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build(deps): bump urllib3 from 2.0.4 to 2.0.7 in /drivers/gpu/drm/ci/xfails #3
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build(deps): bump urllib3 from 2.0.4 to 2.0.7 in /drivers/gpu/drm/ci/xfails #3
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Bumps [urllib3](https://github.com/urllib3/urllib3) from 2.0.4 to 2.0.7. - [Release notes](https://github.com/urllib3/urllib3/releases) - [Changelog](https://github.com/urllib3/urllib3/blob/main/CHANGES.rst) - [Commits](urllib3/urllib3@2.0.4...2.0.7) --- updated-dependencies: - dependency-name: urllib3 dependency-type: direct:production ... Signed-off-by: dependabot[bot] <support@github.com>
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Eduard Zingerman says: ==================== exact states comparison for iterator convergence checks Iterator convergence logic in is_state_visited() uses state_equals() for states with branches counter > 0 to check if iterator based loop converges. This is not fully correct because state_equals() relies on presence of read and precision marks on registers. These marks are not guaranteed to be finalized while state has branches. Commit message for patch #3 describes a program that exhibits such behavior. This patch-set aims to fix iterator convergence logic by adding notion of exact states comparison. Exact comparison does not rely on presence of read or precision marks and thus is more strict. As explained in commit message for patch #3 exact comparisons require addition of speculative register bounds widening. The end result for BPF verifier users could be summarized as follows: (!) After this update verifier would reject programs that conjure an imprecise value on the first loop iteration and use it as precise on the second (for iterator based loops). I urge people to at least skim over the commit message for patch #3. Patches are organized as follows: - patches #1,2: moving/extracting utility functions; - patch #3: introduces exact mode for states comparison and adds widening heuristic; - patch #4: adds test-cases that demonstrate why the series is necessary; - patch #5: extends patch #3 with a notion of state loop entries, these entries have to be tracked to correctly identify that different verifier states belong to the same states loop; - patch gregkh#6: adds a test-case that demonstrates a program which requires loop entry tracking for correct verification; - patch gregkh#7: just adds a few debug prints. The following actions are planned as a followup for this patch-set: - implementation has to be adapted for callbacks handling logic as a part of a fix for [1]; - it is necessary to explore ways to improve widening heuristic to handle iters_task_vma test w/o need to insert barrier_var() calls; - explored states eviction logic on cache miss has to be extended to either: - allow eviction of checkpoint states -or- - be sped up in case if there are many active checkpoints associated with the same instruction. The patch-set is a followup for mailing list discussion [1]. Changelog: - V2 [3] -> V3: - correct check for stack spills in widen_imprecise_scalars(), added test case progs/iters.c:widen_spill to check the behavior (suggested by Andrii); - allow eviction of checkpoint states in is_state_visited() to avoid pathological verifier performance when iterator based loop does not converge (discussion with Alexei). - V1 [2] -> V2, applied changes suggested by Alexei offlist: - __explored_state() function removed; - same_callsites() function is now used in clean_live_states(); - patches #1,2 are added as preparatory code movement; - in process_iter_next_call() a safeguard is added to verify that cur_st->parent exists and has expected insn index / call sites. [1] https://lore.kernel.org/bpf/97a90da09404c65c8e810cf83c94ac703705dc0e.camel@gmail.com/ [2] https://lore.kernel.org/bpf/20231021005939.1041-1-eddyz87@gmail.com/ [3] https://lore.kernel.org/bpf/20231022010812.9201-1-eddyz87@gmail.com/ ==================== Link: https://lore.kernel.org/r/20231024000917.12153-1-eddyz87@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Chuyi Zhou says: ==================== Relax allowlist for open-coded css_task iter Hi, The patchset aims to relax the allowlist for open-coded css_task iter suggested by Alexei[1]. Please see individual patches for more details. And comments are always welcome. Patch summary: * Patch #1: Relax the allowlist and let css_task iter can be used in bpf iters and any sleepable progs. * Patch #2: Add a test in cgroup_iters.c which demonstrates how css_task iters can be combined with cgroup iter. * Patch #3: Add a test to prove css_task iter can be used in normal * sleepable progs. link[1]:https://lore.kernel.org/lkml/CAADnVQKafk_junRyE=-FVAik4hjTRDtThymYGEL8hGTuYoOGpA@mail.gmail.com/ --- Changes in v2: * Fix the incorrect logic in check_css_task_iter_allowlist. Use expected_attach_type to check whether we are using bpf_iters. * Link to v1:https://lore.kernel.org/bpf/20231022154527.229117-1-zhouchuyi@bytedance.com/T/#m946f9cde86b44a13265d9a44c5738a711eb578fd Changes in v3: * Add a testcase to prove css_task can be used in fentry.s * Link to v2:https://lore.kernel.org/bpf/20231024024240.42790-1-zhouchuyi@bytedance.com/T/#m14a97041ff56c2df21bc0149449abd275b73f6a3 Changes in v4: * Add Yonghong's ack for patch #1 and patch #2. * Solve Yonghong's comments for patch #2 * Move prog 'iter_css_task_for_each_sleep' from iters_task_failure.c to iters_css_task.c. Use RUN_TESTS to prove we can load this prog. * Link to v3:https://lore.kernel.org/bpf/20231025075914.30979-1-zhouchuyi@bytedance.com/T/#m3200d8ad29af4ffab97588e297361d0a45d7585d --- ==================== Link: https://lore.kernel.org/r/20231031050438.93297-1-zhouchuyi@bytedance.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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When LAN9303 is MDIO-connected two callchains exist into mdio->bus->write(): 1. switch ports 1&2 ("physical" PHYs): virtual (switch-internal) MDIO bus (lan9303_switch_ops->phy_{read|write})-> lan9303_mdio_phy_{read|write} -> mdiobus_{read|write}_nested 2. LAN9303 virtual PHY: virtual MDIO bus (lan9303_phy_{read|write}) -> lan9303_virt_phy_reg_{read|write} -> regmap -> lan9303_mdio_{read|write} If the latter functions just take mutex_lock(&sw_dev->device->bus->mdio_lock) it triggers a LOCKDEP false-positive splat. It's false-positive because the first mdio_lock in the second callchain above belongs to virtual MDIO bus, the second mdio_lock belongs to physical MDIO bus. Consequent annotation in lan9303_mdio_{read|write} as nested lock (similar to lan9303_mdio_phy_{read|write}, it's the same physical MDIO bus) prevents the following splat: WARNING: possible circular locking dependency detected 5.15.71 #1 Not tainted ------------------------------------------------------ kworker/u4:3/609 is trying to acquire lock: ffff000011531c68 (lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock){+.+.}-{3:3}, at: regmap_lock_mutex but task is already holding lock: ffff0000114c44d8 (&bus->mdio_lock){+.+.}-{3:3}, at: mdiobus_read which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&bus->mdio_lock){+.+.}-{3:3}: lock_acquire __mutex_lock mutex_lock_nested lan9303_mdio_read _regmap_read regmap_read lan9303_probe lan9303_mdio_probe mdio_probe really_probe __driver_probe_device driver_probe_device __device_attach_driver bus_for_each_drv __device_attach device_initial_probe bus_probe_device deferred_probe_work_func process_one_work worker_thread kthread ret_from_fork -> #0 (lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock){+.+.}-{3:3}: __lock_acquire lock_acquire.part.0 lock_acquire __mutex_lock mutex_lock_nested regmap_lock_mutex regmap_read lan9303_phy_read dsa_slave_phy_read __mdiobus_read mdiobus_read get_phy_device mdiobus_scan __mdiobus_register dsa_register_switch lan9303_probe lan9303_mdio_probe mdio_probe really_probe __driver_probe_device driver_probe_device __device_attach_driver bus_for_each_drv __device_attach device_initial_probe bus_probe_device deferred_probe_work_func process_one_work worker_thread kthread ret_from_fork other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&bus->mdio_lock); lock(lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock); lock(&bus->mdio_lock); lock(lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock); *** DEADLOCK *** 5 locks held by kworker/u4:3/609: #0: ffff000002842938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work #1: ffff80000bacbd60 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work #2: ffff000007645178 (&dev->mutex){....}-{3:3}, at: __device_attach #3: ffff8000096e6e78 (dsa2_mutex){+.+.}-{3:3}, at: dsa_register_switch #4: ffff0000114c44d8 (&bus->mdio_lock){+.+.}-{3:3}, at: mdiobus_read stack backtrace: CPU: 1 PID: 609 Comm: kworker/u4:3 Not tainted 5.15.71 #1 Workqueue: events_unbound deferred_probe_work_func Call trace: dump_backtrace show_stack dump_stack_lvl dump_stack print_circular_bug check_noncircular __lock_acquire lock_acquire.part.0 lock_acquire __mutex_lock mutex_lock_nested regmap_lock_mutex regmap_read lan9303_phy_read dsa_slave_phy_read __mdiobus_read mdiobus_read get_phy_device mdiobus_scan __mdiobus_register dsa_register_switch lan9303_probe lan9303_mdio_probe ... Cc: stable@vger.kernel.org Fixes: dc70058 ("net: dsa: LAN9303: add MDIO managed mode support") Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Link: https://lore.kernel.org/r/20231027065741.534971-1-alexander.sverdlin@siemens.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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KMSAN reported the following uninit-value access issue: ===================================================== BUG: KMSAN: uninit-value in virtio_transport_recv_pkt+0x1dfb/0x26a0 net/vmw_vsock/virtio_transport_common.c:1421 virtio_transport_recv_pkt+0x1dfb/0x26a0 net/vmw_vsock/virtio_transport_common.c:1421 vsock_loopback_work+0x3bb/0x5a0 net/vmw_vsock/vsock_loopback.c:120 process_one_work kernel/workqueue.c:2630 [inline] process_scheduled_works+0xff6/0x1e60 kernel/workqueue.c:2703 worker_thread+0xeca/0x14d0 kernel/workqueue.c:2784 kthread+0x3cc/0x520 kernel/kthread.c:388 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 Uninit was stored to memory at: virtio_transport_space_update net/vmw_vsock/virtio_transport_common.c:1274 [inline] virtio_transport_recv_pkt+0x1ee8/0x26a0 net/vmw_vsock/virtio_transport_common.c:1415 vsock_loopback_work+0x3bb/0x5a0 net/vmw_vsock/vsock_loopback.c:120 process_one_work kernel/workqueue.c:2630 [inline] process_scheduled_works+0xff6/0x1e60 kernel/workqueue.c:2703 worker_thread+0xeca/0x14d0 kernel/workqueue.c:2784 kthread+0x3cc/0x520 kernel/kthread.c:388 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 Uninit was created at: slab_post_alloc_hook+0x105/0xad0 mm/slab.h:767 slab_alloc_node mm/slub.c:3478 [inline] kmem_cache_alloc_node+0x5a2/0xaf0 mm/slub.c:3523 kmalloc_reserve+0x13c/0x4a0 net/core/skbuff.c:559 __alloc_skb+0x2fd/0x770 net/core/skbuff.c:650 alloc_skb include/linux/skbuff.h:1286 [inline] virtio_vsock_alloc_skb include/linux/virtio_vsock.h:66 [inline] virtio_transport_alloc_skb+0x90/0x11e0 net/vmw_vsock/virtio_transport_common.c:58 virtio_transport_reset_no_sock net/vmw_vsock/virtio_transport_common.c:957 [inline] virtio_transport_recv_pkt+0x1279/0x26a0 net/vmw_vsock/virtio_transport_common.c:1387 vsock_loopback_work+0x3bb/0x5a0 net/vmw_vsock/vsock_loopback.c:120 process_one_work kernel/workqueue.c:2630 [inline] process_scheduled_works+0xff6/0x1e60 kernel/workqueue.c:2703 worker_thread+0xeca/0x14d0 kernel/workqueue.c:2784 kthread+0x3cc/0x520 kernel/kthread.c:388 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 CPU: 1 PID: 10664 Comm: kworker/1:5 Not tainted 6.6.0-rc3-00146-g9f3ebbef746f #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-1.fc38 04/01/2014 Workqueue: vsock-loopback vsock_loopback_work ===================================================== The following simple reproducer can cause the issue described above: int main(void) { int sock; struct sockaddr_vm addr = { .svm_family = AF_VSOCK, .svm_cid = VMADDR_CID_ANY, .svm_port = 1234, }; sock = socket(AF_VSOCK, SOCK_STREAM, 0); connect(sock, (struct sockaddr *)&addr, sizeof(addr)); return 0; } This issue occurs because the `buf_alloc` and `fwd_cnt` fields of the `struct virtio_vsock_hdr` are not initialized when a new skb is allocated in `virtio_transport_init_hdr()`. This patch resolves the issue by initializing these fields during allocation. Fixes: 71dc9ec ("virtio/vsock: replace virtio_vsock_pkt with sk_buff") Reported-and-tested-by: syzbot+0c8ce1da0ac31abbadcd@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=0c8ce1da0ac31abbadcd Signed-off-by: Shigeru Yoshida <syoshida@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Link: https://lore.kernel.org/r/20231104150531.257952-1-syoshida@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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[ Upstream commit a84fbf2 ] Generating metrics llc_code_read_mpi_demand_plus_prefetch, llc_data_read_mpi_demand_plus_prefetch, llc_miss_local_memory_bandwidth_read, llc_miss_local_memory_bandwidth_write, nllc_miss_remote_memory_bandwidth_read, memory_bandwidth_read, memory_bandwidth_write, uncore_frequency, upi_data_transmit_bw, C2_Pkg_Residency, C3_Core_Residency, C3_Pkg_Residency, C6_Core_Residency, C6_Pkg_Residency, C7_Core_Residency, C7_Pkg_Residency, UNCORE_FREQ and tma_info_system_socket_clks would trigger an address sanitizer heap-buffer-overflows on a SkylakeX. ``` ==2567752==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x5020003ed098 at pc 0x5621a816654e bp 0x7fffb55d4da0 sp 0x7fffb55d4d98 READ of size 4 at 0x5020003eee78 thread T0 #0 0x558265d6654d in aggr_cpu_id__is_empty tools/perf/util/cpumap.c:694:12 #1 0x558265c914da in perf_stat__get_aggr tools/perf/builtin-stat.c:1490:6 #2 0x558265c914da in perf_stat__get_global_cached tools/perf/builtin-stat.c:1530:9 #3 0x558265e53290 in should_skip_zero_counter tools/perf/util/stat-display.c:947:31 #4 0x558265e53290 in print_counter_aggrdata tools/perf/util/stat-display.c:985:18 #5 0x558265e51931 in print_counter tools/perf/util/stat-display.c:1110:3 gregkh#6 0x558265e51931 in evlist__print_counters tools/perf/util/stat-display.c:1571:5 gregkh#7 0x558265c8ec87 in print_counters tools/perf/builtin-stat.c:981:2 gregkh#8 0x558265c8cc71 in cmd_stat tools/perf/builtin-stat.c:2837:3 gregkh#9 0x558265bb9bd4 in run_builtin tools/perf/perf.c:323:11 gregkh#10 0x558265bb98eb in handle_internal_command tools/perf/perf.c:377:8 gregkh#11 0x558265bb9389 in run_argv tools/perf/perf.c:421:2 gregkh#12 0x558265bb9389 in main tools/perf/perf.c:537:3 ``` The issue was the use of testing a cpumap with NULL rather than using empty, as a map containing the dummy value isn't NULL and the -1 results in an empty aggr map being allocated which legitimately overflows when any member is accessed. Fixes: 8a96f45 ("perf stat: Avoid SEGV if core.cpus isn't set") Signed-off-by: Ian Rogers <irogers@google.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20230906003912.3317462-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit ede72dc ] Fuzzing found that an invalid tracepoint name would create a memory leak with an address sanitizer build: ``` $ perf stat -e '*:o/' true event syntax error: '*:o/' \___ parser error Run 'perf list' for a list of valid events Usage: perf stat [<options>] [<command>] -e, --event <event> event selector. use 'perf list' to list available events ================================================================= ==59380==ERROR: LeakSanitizer: detected memory leaks Direct leak of 4 byte(s) in 2 object(s) allocated from: #0 0x7f38ac07077b in __interceptor_strdup ../../../../src/libsanitizer/asan/asan_interceptors.cpp:439 #1 0x55f2f41be73b in str util/parse-events.l:49 #2 0x55f2f41d08e8 in parse_events_lex util/parse-events.l:338 #3 0x55f2f41dc3b1 in parse_events_parse util/parse-events-bison.c:1464 #4 0x55f2f410b8b3 in parse_events__scanner util/parse-events.c:1822 #5 0x55f2f410d1b9 in __parse_events util/parse-events.c:2094 gregkh#6 0x55f2f410e57f in parse_events_option util/parse-events.c:2279 gregkh#7 0x55f2f4427b56 in get_value tools/lib/subcmd/parse-options.c:251 gregkh#8 0x55f2f4428d98 in parse_short_opt tools/lib/subcmd/parse-options.c:351 gregkh#9 0x55f2f4429d80 in parse_options_step tools/lib/subcmd/parse-options.c:539 gregkh#10 0x55f2f442acb9 in parse_options_subcommand tools/lib/subcmd/parse-options.c:654 gregkh#11 0x55f2f3ec99fc in cmd_stat tools/perf/builtin-stat.c:2501 gregkh#12 0x55f2f4093289 in run_builtin tools/perf/perf.c:322 gregkh#13 0x55f2f40937f5 in handle_internal_command tools/perf/perf.c:375 gregkh#14 0x55f2f4093bbd in run_argv tools/perf/perf.c:419 gregkh#15 0x55f2f409412b in main tools/perf/perf.c:535 SUMMARY: AddressSanitizer: 4 byte(s) leaked in 2 allocation(s). ``` Fix by adding the missing destructor. Fixes: 865582c ("perf tools: Adds the tracepoint name parsing support") Signed-off-by: Ian Rogers <irogers@google.com> Cc: He Kuang <hekuang@huawei.com> Link: https://lore.kernel.org/r/20230914164028.363220-1-irogers@google.com Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit d45c4b4 ] A thread started via eg. user_mode_thread() runs in the kernel to begin with and then may later return to userspace. While it's running in the kernel it has a pt_regs at the base of its kernel stack, but that pt_regs is all zeroes. If the thread oopses in that state, it leads to an ugly stack trace with a big block of zero GPRs, as reported by Joel: Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0) CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.5.0-rc7-00004-gf7757129e3de-dirty #3 Hardware name: IBM PowerNV (emulated by qemu) POWER9 0x4e1200 opal:v7.0 PowerNV Call Trace: [c0000000036afb00] [c0000000010dd058] dump_stack_lvl+0x6c/0x9c (unreliable) [c0000000036afb30] [c00000000013c524] panic+0x178/0x424 [c0000000036afbd0] [c000000002005100] mount_root_generic+0x250/0x324 [c0000000036afca0] [c0000000020057d0] prepare_namespace+0x2d4/0x344 [c0000000036afd20] [c0000000020049c0] kernel_init_freeable+0x358/0x3ac [c0000000036afdf0] [c0000000000111b0] kernel_init+0x30/0x1a0 [c0000000036afe50] [c00000000000debc] ret_from_kernel_user_thread+0x14/0x1c --- interrupt: 0 at 0x0 NIP: 0000000000000000 LR: 0000000000000000 CTR: 0000000000000000 REGS: c0000000036afe80 TRAP: 0000 Not tainted (6.5.0-rc7-00004-gf7757129e3de-dirty) MSR: 0000000000000000 <> CR: 00000000 XER: 00000000 CFAR: 0000000000000000 IRQMASK: 0 GPR00: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR04: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR08: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR12: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR24: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR28: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 NIP [0000000000000000] 0x0 LR [0000000000000000] 0x0 --- interrupt: 0 The all-zero pt_regs looks ugly and conveys no useful information, other than its presence. So detect that case and just show the presence of the frame by printing the interrupt marker, eg: Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0) CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.5.0-rc3-00126-g18e9506562a0-dirty #301 Hardware name: IBM pSeries (emulated by qemu) POWER9 (raw) 0x4e1202 0xf000005 of:SLOF,HEAD hv:linux,kvm pSeries Call Trace: [c000000003aabb00] [c000000001143db8] dump_stack_lvl+0x6c/0x9c (unreliable) [c000000003aabb30] [c00000000014c624] panic+0x178/0x424 [c000000003aabbd0] [c0000000020050fc] mount_root_generic+0x250/0x324 [c000000003aabca0] [c0000000020057cc] prepare_namespace+0x2d4/0x344 [c000000003aabd20] [c0000000020049bc] kernel_init_freeable+0x358/0x3ac [c000000003aabdf0] [c0000000000111b0] kernel_init+0x30/0x1a0 [c000000003aabe50] [c00000000000debc] ret_from_kernel_user_thread+0x14/0x1c --- interrupt: 0 at 0x0 To avoid ever suppressing a valid pt_regs make sure the pt_regs has a zero MSR and TRAP value, and is located at the very base of the stack. Fixes: 6895dfc ("powerpc: copy_thread fill in interrupt frame marker and back chain") Reported-by: Joel Stanley <joel@jms.id.au> Reported-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230824064210.907266-1-mpe@ellerman.id.au Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit a84fbf2 ] Generating metrics llc_code_read_mpi_demand_plus_prefetch, llc_data_read_mpi_demand_plus_prefetch, llc_miss_local_memory_bandwidth_read, llc_miss_local_memory_bandwidth_write, nllc_miss_remote_memory_bandwidth_read, memory_bandwidth_read, memory_bandwidth_write, uncore_frequency, upi_data_transmit_bw, C2_Pkg_Residency, C3_Core_Residency, C3_Pkg_Residency, C6_Core_Residency, C6_Pkg_Residency, C7_Core_Residency, C7_Pkg_Residency, UNCORE_FREQ and tma_info_system_socket_clks would trigger an address sanitizer heap-buffer-overflows on a SkylakeX. ``` ==2567752==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x5020003ed098 at pc 0x5621a816654e bp 0x7fffb55d4da0 sp 0x7fffb55d4d98 READ of size 4 at 0x5020003eee78 thread T0 #0 0x558265d6654d in aggr_cpu_id__is_empty tools/perf/util/cpumap.c:694:12 #1 0x558265c914da in perf_stat__get_aggr tools/perf/builtin-stat.c:1490:6 #2 0x558265c914da in perf_stat__get_global_cached tools/perf/builtin-stat.c:1530:9 #3 0x558265e53290 in should_skip_zero_counter tools/perf/util/stat-display.c:947:31 #4 0x558265e53290 in print_counter_aggrdata tools/perf/util/stat-display.c:985:18 #5 0x558265e51931 in print_counter tools/perf/util/stat-display.c:1110:3 gregkh#6 0x558265e51931 in evlist__print_counters tools/perf/util/stat-display.c:1571:5 gregkh#7 0x558265c8ec87 in print_counters tools/perf/builtin-stat.c:981:2 gregkh#8 0x558265c8cc71 in cmd_stat tools/perf/builtin-stat.c:2837:3 gregkh#9 0x558265bb9bd4 in run_builtin tools/perf/perf.c:323:11 gregkh#10 0x558265bb98eb in handle_internal_command tools/perf/perf.c:377:8 gregkh#11 0x558265bb9389 in run_argv tools/perf/perf.c:421:2 gregkh#12 0x558265bb9389 in main tools/perf/perf.c:537:3 ``` The issue was the use of testing a cpumap with NULL rather than using empty, as a map containing the dummy value isn't NULL and the -1 results in an empty aggr map being allocated which legitimately overflows when any member is accessed. Fixes: 8a96f45 ("perf stat: Avoid SEGV if core.cpus isn't set") Signed-off-by: Ian Rogers <irogers@google.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20230906003912.3317462-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit ede72dc ] Fuzzing found that an invalid tracepoint name would create a memory leak with an address sanitizer build: ``` $ perf stat -e '*:o/' true event syntax error: '*:o/' \___ parser error Run 'perf list' for a list of valid events Usage: perf stat [<options>] [<command>] -e, --event <event> event selector. use 'perf list' to list available events ================================================================= ==59380==ERROR: LeakSanitizer: detected memory leaks Direct leak of 4 byte(s) in 2 object(s) allocated from: #0 0x7f38ac07077b in __interceptor_strdup ../../../../src/libsanitizer/asan/asan_interceptors.cpp:439 #1 0x55f2f41be73b in str util/parse-events.l:49 #2 0x55f2f41d08e8 in parse_events_lex util/parse-events.l:338 #3 0x55f2f41dc3b1 in parse_events_parse util/parse-events-bison.c:1464 #4 0x55f2f410b8b3 in parse_events__scanner util/parse-events.c:1822 #5 0x55f2f410d1b9 in __parse_events util/parse-events.c:2094 gregkh#6 0x55f2f410e57f in parse_events_option util/parse-events.c:2279 gregkh#7 0x55f2f4427b56 in get_value tools/lib/subcmd/parse-options.c:251 gregkh#8 0x55f2f4428d98 in parse_short_opt tools/lib/subcmd/parse-options.c:351 gregkh#9 0x55f2f4429d80 in parse_options_step tools/lib/subcmd/parse-options.c:539 gregkh#10 0x55f2f442acb9 in parse_options_subcommand tools/lib/subcmd/parse-options.c:654 gregkh#11 0x55f2f3ec99fc in cmd_stat tools/perf/builtin-stat.c:2501 gregkh#12 0x55f2f4093289 in run_builtin tools/perf/perf.c:322 gregkh#13 0x55f2f40937f5 in handle_internal_command tools/perf/perf.c:375 gregkh#14 0x55f2f4093bbd in run_argv tools/perf/perf.c:419 gregkh#15 0x55f2f409412b in main tools/perf/perf.c:535 SUMMARY: AddressSanitizer: 4 byte(s) leaked in 2 allocation(s). ``` Fix by adding the missing destructor. Fixes: 865582c ("perf tools: Adds the tracepoint name parsing support") Signed-off-by: Ian Rogers <irogers@google.com> Cc: He Kuang <hekuang@huawei.com> Link: https://lore.kernel.org/r/20230914164028.363220-1-irogers@google.com Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit d45c4b4 ] A thread started via eg. user_mode_thread() runs in the kernel to begin with and then may later return to userspace. While it's running in the kernel it has a pt_regs at the base of its kernel stack, but that pt_regs is all zeroes. If the thread oopses in that state, it leads to an ugly stack trace with a big block of zero GPRs, as reported by Joel: Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0) CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.5.0-rc7-00004-gf7757129e3de-dirty #3 Hardware name: IBM PowerNV (emulated by qemu) POWER9 0x4e1200 opal:v7.0 PowerNV Call Trace: [c0000000036afb00] [c0000000010dd058] dump_stack_lvl+0x6c/0x9c (unreliable) [c0000000036afb30] [c00000000013c524] panic+0x178/0x424 [c0000000036afbd0] [c000000002005100] mount_root_generic+0x250/0x324 [c0000000036afca0] [c0000000020057d0] prepare_namespace+0x2d4/0x344 [c0000000036afd20] [c0000000020049c0] kernel_init_freeable+0x358/0x3ac [c0000000036afdf0] [c0000000000111b0] kernel_init+0x30/0x1a0 [c0000000036afe50] [c00000000000debc] ret_from_kernel_user_thread+0x14/0x1c --- interrupt: 0 at 0x0 NIP: 0000000000000000 LR: 0000000000000000 CTR: 0000000000000000 REGS: c0000000036afe80 TRAP: 0000 Not tainted (6.5.0-rc7-00004-gf7757129e3de-dirty) MSR: 0000000000000000 <> CR: 00000000 XER: 00000000 CFAR: 0000000000000000 IRQMASK: 0 GPR00: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR04: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR08: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR12: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR24: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR28: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 NIP [0000000000000000] 0x0 LR [0000000000000000] 0x0 --- interrupt: 0 The all-zero pt_regs looks ugly and conveys no useful information, other than its presence. So detect that case and just show the presence of the frame by printing the interrupt marker, eg: Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0) CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.5.0-rc3-00126-g18e9506562a0-dirty #301 Hardware name: IBM pSeries (emulated by qemu) POWER9 (raw) 0x4e1202 0xf000005 of:SLOF,HEAD hv:linux,kvm pSeries Call Trace: [c000000003aabb00] [c000000001143db8] dump_stack_lvl+0x6c/0x9c (unreliable) [c000000003aabb30] [c00000000014c624] panic+0x178/0x424 [c000000003aabbd0] [c0000000020050fc] mount_root_generic+0x250/0x324 [c000000003aabca0] [c0000000020057cc] prepare_namespace+0x2d4/0x344 [c000000003aabd20] [c0000000020049bc] kernel_init_freeable+0x358/0x3ac [c000000003aabdf0] [c0000000000111b0] kernel_init+0x30/0x1a0 [c000000003aabe50] [c00000000000debc] ret_from_kernel_user_thread+0x14/0x1c --- interrupt: 0 at 0x0 To avoid ever suppressing a valid pt_regs make sure the pt_regs has a zero MSR and TRAP value, and is located at the very base of the stack. Fixes: 6895dfc ("powerpc: copy_thread fill in interrupt frame marker and back chain") Reported-by: Joel Stanley <joel@jms.id.au> Reported-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230824064210.907266-1-mpe@ellerman.id.au Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 34c4eff ] KMSAN reported the following uninit-value access issue: ===================================================== BUG: KMSAN: uninit-value in virtio_transport_recv_pkt+0x1dfb/0x26a0 net/vmw_vsock/virtio_transport_common.c:1421 virtio_transport_recv_pkt+0x1dfb/0x26a0 net/vmw_vsock/virtio_transport_common.c:1421 vsock_loopback_work+0x3bb/0x5a0 net/vmw_vsock/vsock_loopback.c:120 process_one_work kernel/workqueue.c:2630 [inline] process_scheduled_works+0xff6/0x1e60 kernel/workqueue.c:2703 worker_thread+0xeca/0x14d0 kernel/workqueue.c:2784 kthread+0x3cc/0x520 kernel/kthread.c:388 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 Uninit was stored to memory at: virtio_transport_space_update net/vmw_vsock/virtio_transport_common.c:1274 [inline] virtio_transport_recv_pkt+0x1ee8/0x26a0 net/vmw_vsock/virtio_transport_common.c:1415 vsock_loopback_work+0x3bb/0x5a0 net/vmw_vsock/vsock_loopback.c:120 process_one_work kernel/workqueue.c:2630 [inline] process_scheduled_works+0xff6/0x1e60 kernel/workqueue.c:2703 worker_thread+0xeca/0x14d0 kernel/workqueue.c:2784 kthread+0x3cc/0x520 kernel/kthread.c:388 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 Uninit was created at: slab_post_alloc_hook+0x105/0xad0 mm/slab.h:767 slab_alloc_node mm/slub.c:3478 [inline] kmem_cache_alloc_node+0x5a2/0xaf0 mm/slub.c:3523 kmalloc_reserve+0x13c/0x4a0 net/core/skbuff.c:559 __alloc_skb+0x2fd/0x770 net/core/skbuff.c:650 alloc_skb include/linux/skbuff.h:1286 [inline] virtio_vsock_alloc_skb include/linux/virtio_vsock.h:66 [inline] virtio_transport_alloc_skb+0x90/0x11e0 net/vmw_vsock/virtio_transport_common.c:58 virtio_transport_reset_no_sock net/vmw_vsock/virtio_transport_common.c:957 [inline] virtio_transport_recv_pkt+0x1279/0x26a0 net/vmw_vsock/virtio_transport_common.c:1387 vsock_loopback_work+0x3bb/0x5a0 net/vmw_vsock/vsock_loopback.c:120 process_one_work kernel/workqueue.c:2630 [inline] process_scheduled_works+0xff6/0x1e60 kernel/workqueue.c:2703 worker_thread+0xeca/0x14d0 kernel/workqueue.c:2784 kthread+0x3cc/0x520 kernel/kthread.c:388 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 CPU: 1 PID: 10664 Comm: kworker/1:5 Not tainted 6.6.0-rc3-00146-g9f3ebbef746f #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-1.fc38 04/01/2014 Workqueue: vsock-loopback vsock_loopback_work ===================================================== The following simple reproducer can cause the issue described above: int main(void) { int sock; struct sockaddr_vm addr = { .svm_family = AF_VSOCK, .svm_cid = VMADDR_CID_ANY, .svm_port = 1234, }; sock = socket(AF_VSOCK, SOCK_STREAM, 0); connect(sock, (struct sockaddr *)&addr, sizeof(addr)); return 0; } This issue occurs because the `buf_alloc` and `fwd_cnt` fields of the `struct virtio_vsock_hdr` are not initialized when a new skb is allocated in `virtio_transport_init_hdr()`. This patch resolves the issue by initializing these fields during allocation. Fixes: 71dc9ec ("virtio/vsock: replace virtio_vsock_pkt with sk_buff") Reported-and-tested-by: syzbot+0c8ce1da0ac31abbadcd@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=0c8ce1da0ac31abbadcd Signed-off-by: Shigeru Yoshida <syoshida@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Link: https://lore.kernel.org/r/20231104150531.257952-1-syoshida@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
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Andrii Nakryiko says: ==================== BPF control flow graph and precision backtrack fixes A small fix to BPF verifier's CFG logic around handling and reporting ldimm64 instructions. Patch #1 was previously submitted separately ([0]), and so this patch set supersedes that patch. Second patch is fixing obscure corner case in mark_chain_precise() logic. See patch for details. Patch #3 adds a dedicated test, however fragile it might. [0] https://patchwork.kernel.org/project/netdevbpf/patch/20231101205626.119243-1-andrii@kernel.org/ ==================== Link: https://lore.kernel.org/r/20231110002638.4168352-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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This allows it to break the following circular locking dependency. Aug 10 07:01:29 dg1test kernel: ====================================================== Aug 10 07:01:29 dg1test kernel: WARNING: possible circular locking dependency detected Aug 10 07:01:29 dg1test kernel: 6.4.0-rc7+ gregkh#10 Not tainted Aug 10 07:01:29 dg1test kernel: ------------------------------------------------------ Aug 10 07:01:29 dg1test kernel: wireplumber/2236 is trying to acquire lock: Aug 10 07:01:29 dg1test kernel: ffff8fca5320da18 (&fctx->lock){-...}-{2:2}, at: nouveau_fence_wait_uevent_handler+0x2b/0x100 [nouveau] Aug 10 07:01:29 dg1test kernel: but task is already holding lock: Aug 10 07:01:29 dg1test kernel: ffff8fca41208610 (&event->list_lock#2){-...}-{2:2}, at: nvkm_event_ntfy+0x50/0xf0 [nouveau] Aug 10 07:01:29 dg1test kernel: which lock already depends on the new lock. Aug 10 07:01:29 dg1test kernel: the existing dependency chain (in reverse order) is: Aug 10 07:01:29 dg1test kernel: -> #3 (&event->list_lock#2){-...}-{2:2}: Aug 10 07:01:29 dg1test kernel: _raw_spin_lock_irqsave+0x4b/0x70 Aug 10 07:01:29 dg1test kernel: nvkm_event_ntfy+0x50/0xf0 [nouveau] Aug 10 07:01:29 dg1test kernel: ga100_fifo_nonstall_intr+0x24/0x30 [nouveau] Aug 10 07:01:29 dg1test kernel: nvkm_intr+0x12c/0x240 [nouveau] Aug 10 07:01:29 dg1test kernel: __handle_irq_event_percpu+0x88/0x240 Aug 10 07:01:29 dg1test kernel: handle_irq_event+0x38/0x80 Aug 10 07:01:29 dg1test kernel: handle_edge_irq+0xa3/0x240 Aug 10 07:01:29 dg1test kernel: __common_interrupt+0x72/0x160 Aug 10 07:01:29 dg1test kernel: common_interrupt+0x60/0xe0 Aug 10 07:01:29 dg1test kernel: asm_common_interrupt+0x26/0x40 Aug 10 07:01:29 dg1test kernel: -> #2 (&device->intr.lock){-...}-{2:2}: Aug 10 07:01:29 dg1test kernel: _raw_spin_lock_irqsave+0x4b/0x70 Aug 10 07:01:29 dg1test kernel: nvkm_inth_allow+0x2c/0x80 [nouveau] Aug 10 07:01:29 dg1test kernel: nvkm_event_ntfy_state+0x181/0x250 [nouveau] Aug 10 07:01:29 dg1test kernel: nvkm_event_ntfy_allow+0x63/0xd0 [nouveau] Aug 10 07:01:29 dg1test kernel: nvkm_uevent_mthd+0x4d/0x70 [nouveau] Aug 10 07:01:29 dg1test kernel: nvkm_ioctl+0x10b/0x250 [nouveau] Aug 10 07:01:29 dg1test kernel: nvif_object_mthd+0xa8/0x1f0 [nouveau] Aug 10 07:01:29 dg1test kernel: nvif_event_allow+0x2a/0xa0 [nouveau] Aug 10 07:01:29 dg1test kernel: nouveau_fence_enable_signaling+0x78/0x80 [nouveau] Aug 10 07:01:29 dg1test kernel: __dma_fence_enable_signaling+0x5e/0x100 Aug 10 07:01:29 dg1test kernel: dma_fence_add_callback+0x4b/0xd0 Aug 10 07:01:29 dg1test kernel: nouveau_cli_work_queue+0xae/0x110 [nouveau] Aug 10 07:01:29 dg1test kernel: nouveau_gem_object_close+0x1d1/0x2a0 [nouveau] Aug 10 07:01:29 dg1test kernel: drm_gem_handle_delete+0x70/0xe0 [drm] Aug 10 07:01:29 dg1test kernel: drm_ioctl_kernel+0xa5/0x150 [drm] Aug 10 07:01:29 dg1test kernel: drm_ioctl+0x256/0x490 [drm] Aug 10 07:01:29 dg1test kernel: nouveau_drm_ioctl+0x5a/0xb0 [nouveau] Aug 10 07:01:29 dg1test kernel: __x64_sys_ioctl+0x91/0xd0 Aug 10 07:01:29 dg1test kernel: do_syscall_64+0x3c/0x90 Aug 10 07:01:29 dg1test kernel: entry_SYSCALL_64_after_hwframe+0x72/0xdc Aug 10 07:01:29 dg1test kernel: -> #1 (&event->refs_lock#4){....}-{2:2}: Aug 10 07:01:29 dg1test kernel: _raw_spin_lock_irqsave+0x4b/0x70 Aug 10 07:01:29 dg1test kernel: nvkm_event_ntfy_state+0x37/0x250 [nouveau] Aug 10 07:01:29 dg1test kernel: nvkm_event_ntfy_allow+0x63/0xd0 [nouveau] Aug 10 07:01:29 dg1test kernel: nvkm_uevent_mthd+0x4d/0x70 [nouveau] Aug 10 07:01:29 dg1test kernel: nvkm_ioctl+0x10b/0x250 [nouveau] Aug 10 07:01:29 dg1test kernel: nvif_object_mthd+0xa8/0x1f0 [nouveau] Aug 10 07:01:29 dg1test kernel: nvif_event_allow+0x2a/0xa0 [nouveau] Aug 10 07:01:29 dg1test kernel: nouveau_fence_enable_signaling+0x78/0x80 [nouveau] Aug 10 07:01:29 dg1test kernel: __dma_fence_enable_signaling+0x5e/0x100 Aug 10 07:01:29 dg1test kernel: dma_fence_add_callback+0x4b/0xd0 Aug 10 07:01:29 dg1test kernel: nouveau_cli_work_queue+0xae/0x110 [nouveau] Aug 10 07:01:29 dg1test kernel: nouveau_gem_object_close+0x1d1/0x2a0 [nouveau] Aug 10 07:01:29 dg1test kernel: drm_gem_handle_delete+0x70/0xe0 [drm] Aug 10 07:01:29 dg1test kernel: drm_ioctl_kernel+0xa5/0x150 [drm] Aug 10 07:01:29 dg1test kernel: drm_ioctl+0x256/0x490 [drm] Aug 10 07:01:29 dg1test kernel: nouveau_drm_ioctl+0x5a/0xb0 [nouveau] Aug 10 07:01:29 dg1test kernel: __x64_sys_ioctl+0x91/0xd0 Aug 10 07:01:29 dg1test kernel: do_syscall_64+0x3c/0x90 Aug 10 07:01:29 dg1test kernel: entry_SYSCALL_64_after_hwframe+0x72/0xdc Aug 10 07:01:29 dg1test kernel: -> #0 (&fctx->lock){-...}-{2:2}: Aug 10 07:01:29 dg1test kernel: __lock_acquire+0x14e3/0x2240 Aug 10 07:01:29 dg1test kernel: lock_acquire+0xc8/0x2a0 Aug 10 07:01:29 dg1test kernel: _raw_spin_lock_irqsave+0x4b/0x70 Aug 10 07:01:29 dg1test kernel: nouveau_fence_wait_uevent_handler+0x2b/0x100 [nouveau] Aug 10 07:01:29 dg1test kernel: nvkm_client_event+0xf/0x20 [nouveau] Aug 10 07:01:29 dg1test kernel: nvkm_event_ntfy+0x9b/0xf0 [nouveau] Aug 10 07:01:29 dg1test kernel: ga100_fifo_nonstall_intr+0x24/0x30 [nouveau] Aug 10 07:01:29 dg1test kernel: nvkm_intr+0x12c/0x240 [nouveau] Aug 10 07:01:29 dg1test kernel: __handle_irq_event_percpu+0x88/0x240 Aug 10 07:01:29 dg1test kernel: handle_irq_event+0x38/0x80 Aug 10 07:01:29 dg1test kernel: handle_edge_irq+0xa3/0x240 Aug 10 07:01:29 dg1test kernel: __common_interrupt+0x72/0x160 Aug 10 07:01:29 dg1test kernel: common_interrupt+0x60/0xe0 Aug 10 07:01:29 dg1test kernel: asm_common_interrupt+0x26/0x40 Aug 10 07:01:29 dg1test kernel: other info that might help us debug this: Aug 10 07:01:29 dg1test kernel: Chain exists of: &fctx->lock --> &device->intr.lock --> &event->list_lock#2 Aug 10 07:01:29 dg1test kernel: Possible unsafe locking scenario: Aug 10 07:01:29 dg1test kernel: CPU0 CPU1 Aug 10 07:01:29 dg1test kernel: ---- ---- Aug 10 07:01:29 dg1test kernel: lock(&event->list_lock#2); Aug 10 07:01:29 dg1test kernel: lock(&device->intr.lock); Aug 10 07:01:29 dg1test kernel: lock(&event->list_lock#2); Aug 10 07:01:29 dg1test kernel: lock(&fctx->lock); Aug 10 07:01:29 dg1test kernel: *** DEADLOCK *** Aug 10 07:01:29 dg1test kernel: 2 locks held by wireplumber/2236: Aug 10 07:01:29 dg1test kernel: #0: ffff8fca53177bf8 (&device->intr.lock){-...}-{2:2}, at: nvkm_intr+0x29/0x240 [nouveau] Aug 10 07:01:29 dg1test kernel: #1: ffff8fca41208610 (&event->list_lock#2){-...}-{2:2}, at: nvkm_event_ntfy+0x50/0xf0 [nouveau] Aug 10 07:01:29 dg1test kernel: stack backtrace: Aug 10 07:01:29 dg1test kernel: CPU: 6 PID: 2236 Comm: wireplumber Not tainted 6.4.0-rc7+ gregkh#10 Aug 10 07:01:29 dg1test kernel: Hardware name: Gigabyte Technology Co., Ltd. Z390 I AORUS PRO WIFI/Z390 I AORUS PRO WIFI-CF, BIOS F8 11/05/2021 Aug 10 07:01:29 dg1test kernel: Call Trace: Aug 10 07:01:29 dg1test kernel: <TASK> Aug 10 07:01:29 dg1test kernel: dump_stack_lvl+0x5b/0x90 Aug 10 07:01:29 dg1test kernel: check_noncircular+0xe2/0x110 Aug 10 07:01:29 dg1test kernel: __lock_acquire+0x14e3/0x2240 Aug 10 07:01:29 dg1test kernel: lock_acquire+0xc8/0x2a0 Aug 10 07:01:29 dg1test kernel: ? nouveau_fence_wait_uevent_handler+0x2b/0x100 [nouveau] Aug 10 07:01:29 dg1test kernel: ? lock_acquire+0xc8/0x2a0 Aug 10 07:01:29 dg1test kernel: _raw_spin_lock_irqsave+0x4b/0x70 Aug 10 07:01:29 dg1test kernel: ? nouveau_fence_wait_uevent_handler+0x2b/0x100 [nouveau] Aug 10 07:01:29 dg1test kernel: nouveau_fence_wait_uevent_handler+0x2b/0x100 [nouveau] Aug 10 07:01:29 dg1test kernel: nvkm_client_event+0xf/0x20 [nouveau] Aug 10 07:01:29 dg1test kernel: nvkm_event_ntfy+0x9b/0xf0 [nouveau] Aug 10 07:01:29 dg1test kernel: ga100_fifo_nonstall_intr+0x24/0x30 [nouveau] Aug 10 07:01:29 dg1test kernel: nvkm_intr+0x12c/0x240 [nouveau] Aug 10 07:01:29 dg1test kernel: __handle_irq_event_percpu+0x88/0x240 Aug 10 07:01:29 dg1test kernel: handle_irq_event+0x38/0x80 Aug 10 07:01:29 dg1test kernel: handle_edge_irq+0xa3/0x240 Aug 10 07:01:29 dg1test kernel: __common_interrupt+0x72/0x160 Aug 10 07:01:29 dg1test kernel: common_interrupt+0x60/0xe0 Aug 10 07:01:29 dg1test kernel: asm_common_interrupt+0x26/0x40 Aug 10 07:01:29 dg1test kernel: RIP: 0033:0x7fb66174d700 Aug 10 07:01:29 dg1test kernel: Code: c1 e2 05 29 ca 8d 0c 10 0f be 07 84 c0 75 eb 89 c8 c3 0f 1f 84 00 00 00 00 00 f3 0f 1e fa e9 d7 0f fc ff 0f 1f 80 00 00 00 00 <f3> 0f 1e fa e9 c7 0f fc> Aug 10 07:01:29 dg1test kernel: RSP: 002b:00007ffdd3c48438 EFLAGS: 00000206 Aug 10 07:01:29 dg1test kernel: RAX: 000055bb758763c0 RBX: 000055bb758752c0 RCX: 00000000000028b0 Aug 10 07:01:29 dg1test kernel: RDX: 000055bb758752c0 RSI: 000055bb75887490 RDI: 000055bb75862950 Aug 10 07:01:29 dg1test kernel: RBP: 00007ffdd3c48490 R08: 000055bb75873b10 R09: 0000000000000001 Aug 10 07:01:29 dg1test kernel: R10: 0000000000000004 R11: 000055bb7587f000 R12: 000055bb75887490 Aug 10 07:01:29 dg1test kernel: R13: 000055bb757f6280 R14: 000055bb758875c0 R15: 000055bb757f6280 Aug 10 07:01:29 dg1test kernel: </TASK> Signed-off-by: Dave Airlie <airlied@redhat.com> Tested-by: Danilo Krummrich <dakr@redhat.com> Reviewed-by: Danilo Krummrich <dakr@redhat.com> Signed-off-by: Danilo Krummrich <dakr@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20231107053255.2257079-1-airlied@gmail.com
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[ Upstream commit a84fbf2 ] Generating metrics llc_code_read_mpi_demand_plus_prefetch, llc_data_read_mpi_demand_plus_prefetch, llc_miss_local_memory_bandwidth_read, llc_miss_local_memory_bandwidth_write, nllc_miss_remote_memory_bandwidth_read, memory_bandwidth_read, memory_bandwidth_write, uncore_frequency, upi_data_transmit_bw, C2_Pkg_Residency, C3_Core_Residency, C3_Pkg_Residency, C6_Core_Residency, C6_Pkg_Residency, C7_Core_Residency, C7_Pkg_Residency, UNCORE_FREQ and tma_info_system_socket_clks would trigger an address sanitizer heap-buffer-overflows on a SkylakeX. ``` ==2567752==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x5020003ed098 at pc 0x5621a816654e bp 0x7fffb55d4da0 sp 0x7fffb55d4d98 READ of size 4 at 0x5020003eee78 thread T0 #0 0x558265d6654d in aggr_cpu_id__is_empty tools/perf/util/cpumap.c:694:12 #1 0x558265c914da in perf_stat__get_aggr tools/perf/builtin-stat.c:1490:6 #2 0x558265c914da in perf_stat__get_global_cached tools/perf/builtin-stat.c:1530:9 #3 0x558265e53290 in should_skip_zero_counter tools/perf/util/stat-display.c:947:31 #4 0x558265e53290 in print_counter_aggrdata tools/perf/util/stat-display.c:985:18 #5 0x558265e51931 in print_counter tools/perf/util/stat-display.c:1110:3 gregkh#6 0x558265e51931 in evlist__print_counters tools/perf/util/stat-display.c:1571:5 gregkh#7 0x558265c8ec87 in print_counters tools/perf/builtin-stat.c:981:2 gregkh#8 0x558265c8cc71 in cmd_stat tools/perf/builtin-stat.c:2837:3 gregkh#9 0x558265bb9bd4 in run_builtin tools/perf/perf.c:323:11 gregkh#10 0x558265bb98eb in handle_internal_command tools/perf/perf.c:377:8 gregkh#11 0x558265bb9389 in run_argv tools/perf/perf.c:421:2 gregkh#12 0x558265bb9389 in main tools/perf/perf.c:537:3 ``` The issue was the use of testing a cpumap with NULL rather than using empty, as a map containing the dummy value isn't NULL and the -1 results in an empty aggr map being allocated which legitimately overflows when any member is accessed. Fixes: 8a96f45 ("perf stat: Avoid SEGV if core.cpus isn't set") Signed-off-by: Ian Rogers <irogers@google.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20230906003912.3317462-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 34c4eff upstream. KMSAN reported the following uninit-value access issue: ===================================================== BUG: KMSAN: uninit-value in virtio_transport_recv_pkt+0x1dfb/0x26a0 net/vmw_vsock/virtio_transport_common.c:1421 virtio_transport_recv_pkt+0x1dfb/0x26a0 net/vmw_vsock/virtio_transport_common.c:1421 vsock_loopback_work+0x3bb/0x5a0 net/vmw_vsock/vsock_loopback.c:120 process_one_work kernel/workqueue.c:2630 [inline] process_scheduled_works+0xff6/0x1e60 kernel/workqueue.c:2703 worker_thread+0xeca/0x14d0 kernel/workqueue.c:2784 kthread+0x3cc/0x520 kernel/kthread.c:388 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 Uninit was stored to memory at: virtio_transport_space_update net/vmw_vsock/virtio_transport_common.c:1274 [inline] virtio_transport_recv_pkt+0x1ee8/0x26a0 net/vmw_vsock/virtio_transport_common.c:1415 vsock_loopback_work+0x3bb/0x5a0 net/vmw_vsock/vsock_loopback.c:120 process_one_work kernel/workqueue.c:2630 [inline] process_scheduled_works+0xff6/0x1e60 kernel/workqueue.c:2703 worker_thread+0xeca/0x14d0 kernel/workqueue.c:2784 kthread+0x3cc/0x520 kernel/kthread.c:388 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 Uninit was created at: slab_post_alloc_hook+0x105/0xad0 mm/slab.h:767 slab_alloc_node mm/slub.c:3478 [inline] kmem_cache_alloc_node+0x5a2/0xaf0 mm/slub.c:3523 kmalloc_reserve+0x13c/0x4a0 net/core/skbuff.c:559 __alloc_skb+0x2fd/0x770 net/core/skbuff.c:650 alloc_skb include/linux/skbuff.h:1286 [inline] virtio_vsock_alloc_skb include/linux/virtio_vsock.h:66 [inline] virtio_transport_alloc_skb+0x90/0x11e0 net/vmw_vsock/virtio_transport_common.c:58 virtio_transport_reset_no_sock net/vmw_vsock/virtio_transport_common.c:957 [inline] virtio_transport_recv_pkt+0x1279/0x26a0 net/vmw_vsock/virtio_transport_common.c:1387 vsock_loopback_work+0x3bb/0x5a0 net/vmw_vsock/vsock_loopback.c:120 process_one_work kernel/workqueue.c:2630 [inline] process_scheduled_works+0xff6/0x1e60 kernel/workqueue.c:2703 worker_thread+0xeca/0x14d0 kernel/workqueue.c:2784 kthread+0x3cc/0x520 kernel/kthread.c:388 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 CPU: 1 PID: 10664 Comm: kworker/1:5 Not tainted 6.6.0-rc3-00146-g9f3ebbef746f #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-1.fc38 04/01/2014 Workqueue: vsock-loopback vsock_loopback_work ===================================================== The following simple reproducer can cause the issue described above: int main(void) { int sock; struct sockaddr_vm addr = { .svm_family = AF_VSOCK, .svm_cid = VMADDR_CID_ANY, .svm_port = 1234, }; sock = socket(AF_VSOCK, SOCK_STREAM, 0); connect(sock, (struct sockaddr *)&addr, sizeof(addr)); return 0; } This issue occurs because the `buf_alloc` and `fwd_cnt` fields of the `struct virtio_vsock_hdr` are not initialized when a new skb is allocated in `virtio_transport_init_hdr()`. This patch resolves the issue by initializing these fields during allocation. Fixes: 71dc9ec ("virtio/vsock: replace virtio_vsock_pkt with sk_buff") Reported-and-tested-by: syzbot+0c8ce1da0ac31abbadcd@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=0c8ce1da0ac31abbadcd Signed-off-by: Shigeru Yoshida <syoshida@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Link: https://lore.kernel.org/r/20231104150531.257952-1-syoshida@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Looks like urllib3 is up-to-date now, so this is no longer needed. |
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commit 5a22fbc upstream. When LAN9303 is MDIO-connected two callchains exist into mdio->bus->write(): 1. switch ports 1&2 ("physical" PHYs): virtual (switch-internal) MDIO bus (lan9303_switch_ops->phy_{read|write})-> lan9303_mdio_phy_{read|write} -> mdiobus_{read|write}_nested 2. LAN9303 virtual PHY: virtual MDIO bus (lan9303_phy_{read|write}) -> lan9303_virt_phy_reg_{read|write} -> regmap -> lan9303_mdio_{read|write} If the latter functions just take mutex_lock(&sw_dev->device->bus->mdio_lock) it triggers a LOCKDEP false-positive splat. It's false-positive because the first mdio_lock in the second callchain above belongs to virtual MDIO bus, the second mdio_lock belongs to physical MDIO bus. Consequent annotation in lan9303_mdio_{read|write} as nested lock (similar to lan9303_mdio_phy_{read|write}, it's the same physical MDIO bus) prevents the following splat: WARNING: possible circular locking dependency detected 5.15.71 #1 Not tainted ------------------------------------------------------ kworker/u4:3/609 is trying to acquire lock: ffff000011531c68 (lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock){+.+.}-{3:3}, at: regmap_lock_mutex but task is already holding lock: ffff0000114c44d8 (&bus->mdio_lock){+.+.}-{3:3}, at: mdiobus_read which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&bus->mdio_lock){+.+.}-{3:3}: lock_acquire __mutex_lock mutex_lock_nested lan9303_mdio_read _regmap_read regmap_read lan9303_probe lan9303_mdio_probe mdio_probe really_probe __driver_probe_device driver_probe_device __device_attach_driver bus_for_each_drv __device_attach device_initial_probe bus_probe_device deferred_probe_work_func process_one_work worker_thread kthread ret_from_fork -> #0 (lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock){+.+.}-{3:3}: __lock_acquire lock_acquire.part.0 lock_acquire __mutex_lock mutex_lock_nested regmap_lock_mutex regmap_read lan9303_phy_read dsa_slave_phy_read __mdiobus_read mdiobus_read get_phy_device mdiobus_scan __mdiobus_register dsa_register_switch lan9303_probe lan9303_mdio_probe mdio_probe really_probe __driver_probe_device driver_probe_device __device_attach_driver bus_for_each_drv __device_attach device_initial_probe bus_probe_device deferred_probe_work_func process_one_work worker_thread kthread ret_from_fork other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&bus->mdio_lock); lock(lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock); lock(&bus->mdio_lock); lock(lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock); *** DEADLOCK *** 5 locks held by kworker/u4:3/609: #0: ffff000002842938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work #1: ffff80000bacbd60 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work #2: ffff000007645178 (&dev->mutex){....}-{3:3}, at: __device_attach #3: ffff8000096e6e78 (dsa2_mutex){+.+.}-{3:3}, at: dsa_register_switch #4: ffff0000114c44d8 (&bus->mdio_lock){+.+.}-{3:3}, at: mdiobus_read stack backtrace: CPU: 1 PID: 609 Comm: kworker/u4:3 Not tainted 5.15.71 #1 Workqueue: events_unbound deferred_probe_work_func Call trace: dump_backtrace show_stack dump_stack_lvl dump_stack print_circular_bug check_noncircular __lock_acquire lock_acquire.part.0 lock_acquire __mutex_lock mutex_lock_nested regmap_lock_mutex regmap_read lan9303_phy_read dsa_slave_phy_read __mdiobus_read mdiobus_read get_phy_device mdiobus_scan __mdiobus_register dsa_register_switch lan9303_probe lan9303_mdio_probe ... Cc: stable@vger.kernel.org Fixes: dc70058 ("net: dsa: LAN9303: add MDIO managed mode support") Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Link: https://lore.kernel.org/r/20231027065741.534971-1-alexander.sverdlin@siemens.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit dd976a9 upstream. The smp_processor_id() shouldn't be called from preemptible code. Instead use get_cpu() and put_cpu() which disables preemption in addition to getting the processor id. Enable preemption back after calling schedule_work() to make sure that the work gets scheduled on all cores other than the current core. We want to avoid a scenario where current core's stack trace is printed multiple times and one core's stack trace isn't printed because of scheduling of current task. This fixes the following bug: [ 119.143590] sysrq: Show backtrace of all active CPUs [ 119.143902] BUG: using smp_processor_id() in preemptible [00000000] code: bash/873 [ 119.144586] caller is debug_smp_processor_id+0x20/0x30 [ 119.144827] CPU: 6 PID: 873 Comm: bash Not tainted 5.10.124-dirty #3 [ 119.144861] Hardware name: QEMU QEMU Virtual Machine, BIOS 2023.05-1 07/22/2023 [ 119.145053] Call trace: [ 119.145093] dump_backtrace+0x0/0x1a0 [ 119.145122] show_stack+0x18/0x70 [ 119.145141] dump_stack+0xc4/0x11c [ 119.145159] check_preemption_disabled+0x100/0x110 [ 119.145175] debug_smp_processor_id+0x20/0x30 [ 119.145195] sysrq_handle_showallcpus+0x20/0xc0 [ 119.145211] __handle_sysrq+0x8c/0x1a0 [ 119.145227] write_sysrq_trigger+0x94/0x12c [ 119.145247] proc_reg_write+0xa8/0xe4 [ 119.145266] vfs_write+0xec/0x280 [ 119.145282] ksys_write+0x6c/0x100 [ 119.145298] __arm64_sys_write+0x20/0x30 [ 119.145315] el0_svc_common.constprop.0+0x78/0x1e4 [ 119.145332] do_el0_svc+0x24/0x8c [ 119.145348] el0_svc+0x10/0x20 [ 119.145364] el0_sync_handler+0x134/0x140 [ 119.145381] el0_sync+0x180/0x1c0 Cc: jirislaby@kernel.org Cc: stable@vger.kernel.org Fixes: 47cab6a ("debug lockups: Improve lockup detection, fix generic arch fallback") Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com> Link: https://lore.kernel.org/r/20231009162021.3607632-1-usama.anjum@collabora.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 5a22fbc upstream. When LAN9303 is MDIO-connected two callchains exist into mdio->bus->write(): 1. switch ports 1&2 ("physical" PHYs): virtual (switch-internal) MDIO bus (lan9303_switch_ops->phy_{read|write})-> lan9303_mdio_phy_{read|write} -> mdiobus_{read|write}_nested 2. LAN9303 virtual PHY: virtual MDIO bus (lan9303_phy_{read|write}) -> lan9303_virt_phy_reg_{read|write} -> regmap -> lan9303_mdio_{read|write} If the latter functions just take mutex_lock(&sw_dev->device->bus->mdio_lock) it triggers a LOCKDEP false-positive splat. It's false-positive because the first mdio_lock in the second callchain above belongs to virtual MDIO bus, the second mdio_lock belongs to physical MDIO bus. Consequent annotation in lan9303_mdio_{read|write} as nested lock (similar to lan9303_mdio_phy_{read|write}, it's the same physical MDIO bus) prevents the following splat: WARNING: possible circular locking dependency detected 5.15.71 #1 Not tainted ------------------------------------------------------ kworker/u4:3/609 is trying to acquire lock: ffff000011531c68 (lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock){+.+.}-{3:3}, at: regmap_lock_mutex but task is already holding lock: ffff0000114c44d8 (&bus->mdio_lock){+.+.}-{3:3}, at: mdiobus_read which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&bus->mdio_lock){+.+.}-{3:3}: lock_acquire __mutex_lock mutex_lock_nested lan9303_mdio_read _regmap_read regmap_read lan9303_probe lan9303_mdio_probe mdio_probe really_probe __driver_probe_device driver_probe_device __device_attach_driver bus_for_each_drv __device_attach device_initial_probe bus_probe_device deferred_probe_work_func process_one_work worker_thread kthread ret_from_fork -> #0 (lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock){+.+.}-{3:3}: __lock_acquire lock_acquire.part.0 lock_acquire __mutex_lock mutex_lock_nested regmap_lock_mutex regmap_read lan9303_phy_read dsa_slave_phy_read __mdiobus_read mdiobus_read get_phy_device mdiobus_scan __mdiobus_register dsa_register_switch lan9303_probe lan9303_mdio_probe mdio_probe really_probe __driver_probe_device driver_probe_device __device_attach_driver bus_for_each_drv __device_attach device_initial_probe bus_probe_device deferred_probe_work_func process_one_work worker_thread kthread ret_from_fork other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&bus->mdio_lock); lock(lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock); lock(&bus->mdio_lock); lock(lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock); *** DEADLOCK *** 5 locks held by kworker/u4:3/609: #0: ffff000002842938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work #1: ffff80000bacbd60 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work #2: ffff000007645178 (&dev->mutex){....}-{3:3}, at: __device_attach #3: ffff8000096e6e78 (dsa2_mutex){+.+.}-{3:3}, at: dsa_register_switch #4: ffff0000114c44d8 (&bus->mdio_lock){+.+.}-{3:3}, at: mdiobus_read stack backtrace: CPU: 1 PID: 609 Comm: kworker/u4:3 Not tainted 5.15.71 #1 Workqueue: events_unbound deferred_probe_work_func Call trace: dump_backtrace show_stack dump_stack_lvl dump_stack print_circular_bug check_noncircular __lock_acquire lock_acquire.part.0 lock_acquire __mutex_lock mutex_lock_nested regmap_lock_mutex regmap_read lan9303_phy_read dsa_slave_phy_read __mdiobus_read mdiobus_read get_phy_device mdiobus_scan __mdiobus_register dsa_register_switch lan9303_probe lan9303_mdio_probe ... Cc: stable@vger.kernel.org Fixes: dc70058 ("net: dsa: LAN9303: add MDIO managed mode support") Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Link: https://lore.kernel.org/r/20231027065741.534971-1-alexander.sverdlin@siemens.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 5a22fbc upstream. When LAN9303 is MDIO-connected two callchains exist into mdio->bus->write(): 1. switch ports 1&2 ("physical" PHYs): virtual (switch-internal) MDIO bus (lan9303_switch_ops->phy_{read|write})-> lan9303_mdio_phy_{read|write} -> mdiobus_{read|write}_nested 2. LAN9303 virtual PHY: virtual MDIO bus (lan9303_phy_{read|write}) -> lan9303_virt_phy_reg_{read|write} -> regmap -> lan9303_mdio_{read|write} If the latter functions just take mutex_lock(&sw_dev->device->bus->mdio_lock) it triggers a LOCKDEP false-positive splat. It's false-positive because the first mdio_lock in the second callchain above belongs to virtual MDIO bus, the second mdio_lock belongs to physical MDIO bus. Consequent annotation in lan9303_mdio_{read|write} as nested lock (similar to lan9303_mdio_phy_{read|write}, it's the same physical MDIO bus) prevents the following splat: WARNING: possible circular locking dependency detected 5.15.71 #1 Not tainted ------------------------------------------------------ kworker/u4:3/609 is trying to acquire lock: ffff000011531c68 (lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock){+.+.}-{3:3}, at: regmap_lock_mutex but task is already holding lock: ffff0000114c44d8 (&bus->mdio_lock){+.+.}-{3:3}, at: mdiobus_read which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&bus->mdio_lock){+.+.}-{3:3}: lock_acquire __mutex_lock mutex_lock_nested lan9303_mdio_read _regmap_read regmap_read lan9303_probe lan9303_mdio_probe mdio_probe really_probe __driver_probe_device driver_probe_device __device_attach_driver bus_for_each_drv __device_attach device_initial_probe bus_probe_device deferred_probe_work_func process_one_work worker_thread kthread ret_from_fork -> #0 (lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock){+.+.}-{3:3}: __lock_acquire lock_acquire.part.0 lock_acquire __mutex_lock mutex_lock_nested regmap_lock_mutex regmap_read lan9303_phy_read dsa_slave_phy_read __mdiobus_read mdiobus_read get_phy_device mdiobus_scan __mdiobus_register dsa_register_switch lan9303_probe lan9303_mdio_probe mdio_probe really_probe __driver_probe_device driver_probe_device __device_attach_driver bus_for_each_drv __device_attach device_initial_probe bus_probe_device deferred_probe_work_func process_one_work worker_thread kthread ret_from_fork other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&bus->mdio_lock); lock(lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock); lock(&bus->mdio_lock); lock(lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock); *** DEADLOCK *** 5 locks held by kworker/u4:3/609: #0: ffff000002842938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work #1: ffff80000bacbd60 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work #2: ffff000007645178 (&dev->mutex){....}-{3:3}, at: __device_attach #3: ffff8000096e6e78 (dsa2_mutex){+.+.}-{3:3}, at: dsa_register_switch #4: ffff0000114c44d8 (&bus->mdio_lock){+.+.}-{3:3}, at: mdiobus_read stack backtrace: CPU: 1 PID: 609 Comm: kworker/u4:3 Not tainted 5.15.71 #1 Workqueue: events_unbound deferred_probe_work_func Call trace: dump_backtrace show_stack dump_stack_lvl dump_stack print_circular_bug check_noncircular __lock_acquire lock_acquire.part.0 lock_acquire __mutex_lock mutex_lock_nested regmap_lock_mutex regmap_read lan9303_phy_read dsa_slave_phy_read __mdiobus_read mdiobus_read get_phy_device mdiobus_scan __mdiobus_register dsa_register_switch lan9303_probe lan9303_mdio_probe ... Cc: stable@vger.kernel.org Fixes: dc70058 ("net: dsa: LAN9303: add MDIO managed mode support") Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Link: https://lore.kernel.org/r/20231027065741.534971-1-alexander.sverdlin@siemens.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 5a22fbc upstream. When LAN9303 is MDIO-connected two callchains exist into mdio->bus->write(): 1. switch ports 1&2 ("physical" PHYs): virtual (switch-internal) MDIO bus (lan9303_switch_ops->phy_{read|write})-> lan9303_mdio_phy_{read|write} -> mdiobus_{read|write}_nested 2. LAN9303 virtual PHY: virtual MDIO bus (lan9303_phy_{read|write}) -> lan9303_virt_phy_reg_{read|write} -> regmap -> lan9303_mdio_{read|write} If the latter functions just take mutex_lock(&sw_dev->device->bus->mdio_lock) it triggers a LOCKDEP false-positive splat. It's false-positive because the first mdio_lock in the second callchain above belongs to virtual MDIO bus, the second mdio_lock belongs to physical MDIO bus. Consequent annotation in lan9303_mdio_{read|write} as nested lock (similar to lan9303_mdio_phy_{read|write}, it's the same physical MDIO bus) prevents the following splat: WARNING: possible circular locking dependency detected 5.15.71 #1 Not tainted ------------------------------------------------------ kworker/u4:3/609 is trying to acquire lock: ffff000011531c68 (lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock){+.+.}-{3:3}, at: regmap_lock_mutex but task is already holding lock: ffff0000114c44d8 (&bus->mdio_lock){+.+.}-{3:3}, at: mdiobus_read which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&bus->mdio_lock){+.+.}-{3:3}: lock_acquire __mutex_lock mutex_lock_nested lan9303_mdio_read _regmap_read regmap_read lan9303_probe lan9303_mdio_probe mdio_probe really_probe __driver_probe_device driver_probe_device __device_attach_driver bus_for_each_drv __device_attach device_initial_probe bus_probe_device deferred_probe_work_func process_one_work worker_thread kthread ret_from_fork -> #0 (lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock){+.+.}-{3:3}: __lock_acquire lock_acquire.part.0 lock_acquire __mutex_lock mutex_lock_nested regmap_lock_mutex regmap_read lan9303_phy_read dsa_slave_phy_read __mdiobus_read mdiobus_read get_phy_device mdiobus_scan __mdiobus_register dsa_register_switch lan9303_probe lan9303_mdio_probe mdio_probe really_probe __driver_probe_device driver_probe_device __device_attach_driver bus_for_each_drv __device_attach device_initial_probe bus_probe_device deferred_probe_work_func process_one_work worker_thread kthread ret_from_fork other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&bus->mdio_lock); lock(lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock); lock(&bus->mdio_lock); lock(lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock); *** DEADLOCK *** 5 locks held by kworker/u4:3/609: #0: ffff000002842938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work #1: ffff80000bacbd60 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work #2: ffff000007645178 (&dev->mutex){....}-{3:3}, at: __device_attach #3: ffff8000096e6e78 (dsa2_mutex){+.+.}-{3:3}, at: dsa_register_switch #4: ffff0000114c44d8 (&bus->mdio_lock){+.+.}-{3:3}, at: mdiobus_read stack backtrace: CPU: 1 PID: 609 Comm: kworker/u4:3 Not tainted 5.15.71 #1 Workqueue: events_unbound deferred_probe_work_func Call trace: dump_backtrace show_stack dump_stack_lvl dump_stack print_circular_bug check_noncircular __lock_acquire lock_acquire.part.0 lock_acquire __mutex_lock mutex_lock_nested regmap_lock_mutex regmap_read lan9303_phy_read dsa_slave_phy_read __mdiobus_read mdiobus_read get_phy_device mdiobus_scan __mdiobus_register dsa_register_switch lan9303_probe lan9303_mdio_probe ... Cc: stable@vger.kernel.org Fixes: dc70058 ("net: dsa: LAN9303: add MDIO managed mode support") Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Link: https://lore.kernel.org/r/20231027065741.534971-1-alexander.sverdlin@siemens.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit dd976a9 upstream. The smp_processor_id() shouldn't be called from preemptible code. Instead use get_cpu() and put_cpu() which disables preemption in addition to getting the processor id. Enable preemption back after calling schedule_work() to make sure that the work gets scheduled on all cores other than the current core. We want to avoid a scenario where current core's stack trace is printed multiple times and one core's stack trace isn't printed because of scheduling of current task. This fixes the following bug: [ 119.143590] sysrq: Show backtrace of all active CPUs [ 119.143902] BUG: using smp_processor_id() in preemptible [00000000] code: bash/873 [ 119.144586] caller is debug_smp_processor_id+0x20/0x30 [ 119.144827] CPU: 6 PID: 873 Comm: bash Not tainted 5.10.124-dirty #3 [ 119.144861] Hardware name: QEMU QEMU Virtual Machine, BIOS 2023.05-1 07/22/2023 [ 119.145053] Call trace: [ 119.145093] dump_backtrace+0x0/0x1a0 [ 119.145122] show_stack+0x18/0x70 [ 119.145141] dump_stack+0xc4/0x11c [ 119.145159] check_preemption_disabled+0x100/0x110 [ 119.145175] debug_smp_processor_id+0x20/0x30 [ 119.145195] sysrq_handle_showallcpus+0x20/0xc0 [ 119.145211] __handle_sysrq+0x8c/0x1a0 [ 119.145227] write_sysrq_trigger+0x94/0x12c [ 119.145247] proc_reg_write+0xa8/0xe4 [ 119.145266] vfs_write+0xec/0x280 [ 119.145282] ksys_write+0x6c/0x100 [ 119.145298] __arm64_sys_write+0x20/0x30 [ 119.145315] el0_svc_common.constprop.0+0x78/0x1e4 [ 119.145332] do_el0_svc+0x24/0x8c [ 119.145348] el0_svc+0x10/0x20 [ 119.145364] el0_sync_handler+0x134/0x140 [ 119.145381] el0_sync+0x180/0x1c0 Cc: jirislaby@kernel.org Cc: stable@vger.kernel.org Fixes: 47cab6a ("debug lockups: Improve lockup detection, fix generic arch fallback") Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com> Link: https://lore.kernel.org/r/20231009162021.3607632-1-usama.anjum@collabora.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Nov 28, 2023
commit 5a22fbc upstream. When LAN9303 is MDIO-connected two callchains exist into mdio->bus->write(): 1. switch ports 1&2 ("physical" PHYs): virtual (switch-internal) MDIO bus (lan9303_switch_ops->phy_{read|write})-> lan9303_mdio_phy_{read|write} -> mdiobus_{read|write}_nested 2. LAN9303 virtual PHY: virtual MDIO bus (lan9303_phy_{read|write}) -> lan9303_virt_phy_reg_{read|write} -> regmap -> lan9303_mdio_{read|write} If the latter functions just take mutex_lock(&sw_dev->device->bus->mdio_lock) it triggers a LOCKDEP false-positive splat. It's false-positive because the first mdio_lock in the second callchain above belongs to virtual MDIO bus, the second mdio_lock belongs to physical MDIO bus. Consequent annotation in lan9303_mdio_{read|write} as nested lock (similar to lan9303_mdio_phy_{read|write}, it's the same physical MDIO bus) prevents the following splat: WARNING: possible circular locking dependency detected 5.15.71 #1 Not tainted ------------------------------------------------------ kworker/u4:3/609 is trying to acquire lock: ffff000011531c68 (lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock){+.+.}-{3:3}, at: regmap_lock_mutex but task is already holding lock: ffff0000114c44d8 (&bus->mdio_lock){+.+.}-{3:3}, at: mdiobus_read which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&bus->mdio_lock){+.+.}-{3:3}: lock_acquire __mutex_lock mutex_lock_nested lan9303_mdio_read _regmap_read regmap_read lan9303_probe lan9303_mdio_probe mdio_probe really_probe __driver_probe_device driver_probe_device __device_attach_driver bus_for_each_drv __device_attach device_initial_probe bus_probe_device deferred_probe_work_func process_one_work worker_thread kthread ret_from_fork -> #0 (lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock){+.+.}-{3:3}: __lock_acquire lock_acquire.part.0 lock_acquire __mutex_lock mutex_lock_nested regmap_lock_mutex regmap_read lan9303_phy_read dsa_slave_phy_read __mdiobus_read mdiobus_read get_phy_device mdiobus_scan __mdiobus_register dsa_register_switch lan9303_probe lan9303_mdio_probe mdio_probe really_probe __driver_probe_device driver_probe_device __device_attach_driver bus_for_each_drv __device_attach device_initial_probe bus_probe_device deferred_probe_work_func process_one_work worker_thread kthread ret_from_fork other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&bus->mdio_lock); lock(lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock); lock(&bus->mdio_lock); lock(lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock); *** DEADLOCK *** 5 locks held by kworker/u4:3/609: #0: ffff000002842938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work #1: ffff80000bacbd60 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work #2: ffff000007645178 (&dev->mutex){....}-{3:3}, at: __device_attach #3: ffff8000096e6e78 (dsa2_mutex){+.+.}-{3:3}, at: dsa_register_switch #4: ffff0000114c44d8 (&bus->mdio_lock){+.+.}-{3:3}, at: mdiobus_read stack backtrace: CPU: 1 PID: 609 Comm: kworker/u4:3 Not tainted 5.15.71 #1 Workqueue: events_unbound deferred_probe_work_func Call trace: dump_backtrace show_stack dump_stack_lvl dump_stack print_circular_bug check_noncircular __lock_acquire lock_acquire.part.0 lock_acquire __mutex_lock mutex_lock_nested regmap_lock_mutex regmap_read lan9303_phy_read dsa_slave_phy_read __mdiobus_read mdiobus_read get_phy_device mdiobus_scan __mdiobus_register dsa_register_switch lan9303_probe lan9303_mdio_probe ... Cc: stable@vger.kernel.org Fixes: dc70058 ("net: dsa: LAN9303: add MDIO managed mode support") Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Link: https://lore.kernel.org/r/20231027065741.534971-1-alexander.sverdlin@siemens.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit dd976a9 upstream. The smp_processor_id() shouldn't be called from preemptible code. Instead use get_cpu() and put_cpu() which disables preemption in addition to getting the processor id. Enable preemption back after calling schedule_work() to make sure that the work gets scheduled on all cores other than the current core. We want to avoid a scenario where current core's stack trace is printed multiple times and one core's stack trace isn't printed because of scheduling of current task. This fixes the following bug: [ 119.143590] sysrq: Show backtrace of all active CPUs [ 119.143902] BUG: using smp_processor_id() in preemptible [00000000] code: bash/873 [ 119.144586] caller is debug_smp_processor_id+0x20/0x30 [ 119.144827] CPU: 6 PID: 873 Comm: bash Not tainted 5.10.124-dirty #3 [ 119.144861] Hardware name: QEMU QEMU Virtual Machine, BIOS 2023.05-1 07/22/2023 [ 119.145053] Call trace: [ 119.145093] dump_backtrace+0x0/0x1a0 [ 119.145122] show_stack+0x18/0x70 [ 119.145141] dump_stack+0xc4/0x11c [ 119.145159] check_preemption_disabled+0x100/0x110 [ 119.145175] debug_smp_processor_id+0x20/0x30 [ 119.145195] sysrq_handle_showallcpus+0x20/0xc0 [ 119.145211] __handle_sysrq+0x8c/0x1a0 [ 119.145227] write_sysrq_trigger+0x94/0x12c [ 119.145247] proc_reg_write+0xa8/0xe4 [ 119.145266] vfs_write+0xec/0x280 [ 119.145282] ksys_write+0x6c/0x100 [ 119.145298] __arm64_sys_write+0x20/0x30 [ 119.145315] el0_svc_common.constprop.0+0x78/0x1e4 [ 119.145332] do_el0_svc+0x24/0x8c [ 119.145348] el0_svc+0x10/0x20 [ 119.145364] el0_sync_handler+0x134/0x140 [ 119.145381] el0_sync+0x180/0x1c0 Cc: jirislaby@kernel.org Cc: stable@vger.kernel.org Fixes: 47cab6a ("debug lockups: Improve lockup detection, fix generic arch fallback") Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com> Link: https://lore.kernel.org/r/20231009162021.3607632-1-usama.anjum@collabora.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 5a22fbc upstream. When LAN9303 is MDIO-connected two callchains exist into mdio->bus->write(): 1. switch ports 1&2 ("physical" PHYs): virtual (switch-internal) MDIO bus (lan9303_switch_ops->phy_{read|write})-> lan9303_mdio_phy_{read|write} -> mdiobus_{read|write}_nested 2. LAN9303 virtual PHY: virtual MDIO bus (lan9303_phy_{read|write}) -> lan9303_virt_phy_reg_{read|write} -> regmap -> lan9303_mdio_{read|write} If the latter functions just take mutex_lock(&sw_dev->device->bus->mdio_lock) it triggers a LOCKDEP false-positive splat. It's false-positive because the first mdio_lock in the second callchain above belongs to virtual MDIO bus, the second mdio_lock belongs to physical MDIO bus. Consequent annotation in lan9303_mdio_{read|write} as nested lock (similar to lan9303_mdio_phy_{read|write}, it's the same physical MDIO bus) prevents the following splat: WARNING: possible circular locking dependency detected 5.15.71 #1 Not tainted ------------------------------------------------------ kworker/u4:3/609 is trying to acquire lock: ffff000011531c68 (lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock){+.+.}-{3:3}, at: regmap_lock_mutex but task is already holding lock: ffff0000114c44d8 (&bus->mdio_lock){+.+.}-{3:3}, at: mdiobus_read which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&bus->mdio_lock){+.+.}-{3:3}: lock_acquire __mutex_lock mutex_lock_nested lan9303_mdio_read _regmap_read regmap_read lan9303_probe lan9303_mdio_probe mdio_probe really_probe __driver_probe_device driver_probe_device __device_attach_driver bus_for_each_drv __device_attach device_initial_probe bus_probe_device deferred_probe_work_func process_one_work worker_thread kthread ret_from_fork -> #0 (lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock){+.+.}-{3:3}: __lock_acquire lock_acquire.part.0 lock_acquire __mutex_lock mutex_lock_nested regmap_lock_mutex regmap_read lan9303_phy_read dsa_slave_phy_read __mdiobus_read mdiobus_read get_phy_device mdiobus_scan __mdiobus_register dsa_register_switch lan9303_probe lan9303_mdio_probe mdio_probe really_probe __driver_probe_device driver_probe_device __device_attach_driver bus_for_each_drv __device_attach device_initial_probe bus_probe_device deferred_probe_work_func process_one_work worker_thread kthread ret_from_fork other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&bus->mdio_lock); lock(lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock); lock(&bus->mdio_lock); lock(lan9303_mdio:131:(&lan9303_mdio_regmap_config)->lock); *** DEADLOCK *** 5 locks held by kworker/u4:3/609: #0: ffff000002842938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work #1: ffff80000bacbd60 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work #2: ffff000007645178 (&dev->mutex){....}-{3:3}, at: __device_attach #3: ffff8000096e6e78 (dsa2_mutex){+.+.}-{3:3}, at: dsa_register_switch #4: ffff0000114c44d8 (&bus->mdio_lock){+.+.}-{3:3}, at: mdiobus_read stack backtrace: CPU: 1 PID: 609 Comm: kworker/u4:3 Not tainted 5.15.71 #1 Workqueue: events_unbound deferred_probe_work_func Call trace: dump_backtrace show_stack dump_stack_lvl dump_stack print_circular_bug check_noncircular __lock_acquire lock_acquire.part.0 lock_acquire __mutex_lock mutex_lock_nested regmap_lock_mutex regmap_read lan9303_phy_read dsa_slave_phy_read __mdiobus_read mdiobus_read get_phy_device mdiobus_scan __mdiobus_register dsa_register_switch lan9303_probe lan9303_mdio_probe ... Cc: stable@vger.kernel.org Fixes: dc70058 ("net: dsa: LAN9303: add MDIO managed mode support") Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Link: https://lore.kernel.org/r/20231027065741.534971-1-alexander.sverdlin@siemens.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Nov 28, 2023
…f-times' Eduard Zingerman says: ==================== verify callbacks as if they are called unknown number of times This series updates verifier logic for callback functions handling. Current master simulates callback body execution exactly once, which leads to verifier not detecting unsafe programs like below: static int unsafe_on_zero_iter_cb(__u32 idx, struct num_context *ctx) { ctx->i = 0; return 0; } SEC("?raw_tp") int unsafe_on_zero_iter(void *unused) { struct num_context loop_ctx = { .i = 32 }; __u8 choice_arr[2] = { 0, 1 }; bpf_loop(100, unsafe_on_zero_iter_cb, &loop_ctx, 0); return choice_arr[loop_ctx.i]; } This was reported previously in [0]. The basic idea of the fix is to schedule callback entry state for verification in env->head until some identical, previously visited state in current DFS state traversal is found. Same logic as with open coded iterators, and builds on top recent fixes [1] for those. The series is structured as follows: - patches #1,2,3 update strobemeta, xdp_synproxy selftests and bpf_loop_bench benchmark to allow convergence of the bpf_loop callback states; - patches #4,5 just shuffle the code a bit; - patch gregkh#6 is the main part of the series; - patch gregkh#7 adds test cases for gregkh#6; - patch gregkh#8 extend patch gregkh#6 with same speculative scalar widening logic, as used for open coded iterators; - patch gregkh#9 adds test cases for gregkh#8; - patch gregkh#10 extends patch gregkh#6 to track maximal number of callback executions specifically for bpf_loop(); - patch gregkh#11 adds test cases for gregkh#10. Veristat results comparing this series to master+patches #1,2,3 using selftests show the following difference: File Program States (A) States (B) States (DIFF) ------------------------- ------------- ---------- ---------- ------------- bpf_loop_bench.bpf.o benchmark 1 2 +1 (+100.00%) pyperf600_bpf_loop.bpf.o on_event 322 407 +85 (+26.40%) strobemeta_bpf_loop.bpf.o on_event 113 151 +38 (+33.63%) xdp_synproxy_kern.bpf.o syncookie_tc 341 291 -50 (-14.66%) xdp_synproxy_kern.bpf.o syncookie_xdp 344 301 -43 (-12.50%) Veristat results comparing this series to master using Tetragon BPF files [2] also show some differences. States diff varies from +2% to +15% on 23 programs out of 186, no new failures. Changelog: - V3 [5] -> V4, changes suggested by Andrii: - validate mark_chain_precision() result in patch gregkh#10; - renaming s/cumulative_callback_depth/callback_unroll_depth/. - V2 [4] -> V3: - fixes in expected log messages for test cases: - callback_result_precise; - parent_callee_saved_reg_precise_with_callback; - parent_stack_slot_precise_with_callback; - renamings (suggested by Alexei): - s/callback_iter_depth/cumulative_callback_depth/ - s/is_callback_iter_next/calls_callback/ - s/mark_callback_iter_next/mark_calls_callback/ - prepare_func_exit() updated to exit with -EFAULT when callee->in_callback_fn is true but calls_callback() is not true for callsite; - test case 'bpf_loop_iter_limit_nested' rewritten to use return value check instead of verifier log message checks (suggested by Alexei). - V1 [3] -> V2, changes suggested by Andrii: - small changes for error handling code in __check_func_call(); - callback body processing log is now matched in relevant verifier_subprog_precision.c tests; - R1 passed to bpf_loop() is now always marked as precise; - log level 2 message for bpf_loop() iteration termination instead of iteration depth messages; - __no_msg macro removed; - bpf_loop_iter_limit_nested updated to avoid using __no_msg; - commit message for patch #3 updated according to Alexei's request. [0] https://lore.kernel.org/bpf/CA+vRuzPChFNXmouzGG+wsy=6eMcfr1mFG0F3g7rbg-sedGKW3w@mail.gmail.com/ [1] https://lore.kernel.org/bpf/20231024000917.12153-1-eddyz87@gmail.com/ [2] git@github.com:cilium/tetragon.git [3] https://lore.kernel.org/bpf/20231116021803.9982-1-eddyz87@gmail.com/T/#t [4] https://lore.kernel.org/bpf/20231118013355.7943-1-eddyz87@gmail.com/T/#t [5] https://lore.kernel.org/bpf/20231120225945.11741-1-eddyz87@gmail.com/T/#t ==================== Link: https://lore.kernel.org/r/20231121020701.26440-1-eddyz87@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
aahmed71
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Jun 24, 2025
Commit c68cf52 upstream Currently, when CONFIG_ARM64_PTR_AUTH_KERNEL=y (and CONFIG_UNWIND_PATCH_PAC_INTO_SCS=n), we enable pointer authentication for all functions, including leaf functions. This isn't necessary, and is unfortunate for a few reasons: * Any PACIASP instruction is implicitly a `BTI C` landing pad, and forcing the addition of a PACIASP in every function introduces a larger set of BTI gadgets than is necessary. * The PACIASP and AUTIASP instructions make leaf functions larger than necessary, bloating the kernel Image. For a defconfig v6.2-rc3 kernel, this appears to add ~64KiB relative to not signing leaf functions, which is unfortunate but not entirely onerous. * The PACIASP and AUTIASP instructions potentially make leaf functions more expensive in terms of performance and/or power. For many trivial leaf functions, this is clearly unnecessary, e.g. | <arch_local_save_flags>: | d503233f paciasp | d53b4220 mrs x0, daif | d50323bf autiasp | d65f03c0 ret | <calibration_delay_done>: | d503233f paciasp | d50323bf autiasp | d65f03c0 ret | d503201f nop * When CONFIG_UNWIND_PATCH_PAC_INTO_SCS=y we disable pointer authentication for leaf functions, so clearly this is not functionally necessary, indicates we have an inconsistent threat model, and convolutes the Makefile logic. We've used pointer authentication in leaf functions since the introduction of in-kernel pointer authentication in commit: 74afda4 ("arm64: compile the kernel with ptrauth return address signing") ... but at the time we had no rationale for signing leaf functions. Subsequently, we considered avoiding signing leaf functions: https://lore.kernel.org/linux-arm-kernel/1586856741-26839-1-git-send-email-amit.kachhap@arm.com/ https://lore.kernel.org/linux-arm-kernel/1588149371-20310-1-git-send-email-amit.kachhap@arm.com/ ... however at the time we didn't have an abundance of reasons to avoid signing leaf functions as above (e.g. the BTI case), we had no hardware to make performance measurements, and it was reasoned that this gave some level of protection against a limited set of code-reuse gadgets which would fall through to a RET. We documented this in commit: 717b938 ("arm64: Document why we enable PAC support for leaf functions") Notably, this was before we supported any forward-edge CFI scheme (e.g. Arm BTI, or Clang CFI/kCFI), which would prevent jumping into the middle of a function. In addition, even with signing forced for leaf functions, AUTIASP may be placed before a number of instructions which might constitute such a gadget, e.g. | <user_regs_reset_single_step>: | f9400022 ldr x2, [x1] | d503233f paciasp | d50323bf autiasp | f9408401 ldr x1, [x0, #264] | 720b005f tst w2, #0x200000 | b26b0022 orr x2, x1, #0x200000 | 926af821 and x1, x1, #0xffffffffffdfffff | 9a820021 csel x1, x1, x2, eq // eq = none | f9008401 str x1, [x0, #264] | d65f03c0 ret | <fpsimd_cpu_dead>: | 2a0003e3 mov w3, w0 | 9000ff42 adrp x2, ffff800009ffd000 <xen_dynamic_chip+0x48> | 9120e042 add x2, x2, #0x838 | 52800000 mov w0, #0x0 // #0 | d503233f paciasp | f000d041 adrp x1, ffff800009a20000 <this_cpu_vector> | d50323bf autiasp | 9102c021 add x1, x1, #0xb0 | f8635842 ldr x2, [x2, w3, uxtw #3] | f821685f str xzr, [x2, x1] | d65f03c0 ret | d503201f nop So generally, trying to use AUTIASP to detect such gadgetization is not robust, and this is dealt with far better by forward-edge CFI (which is designed to prevent such cases). We should bite the bullet and stop pretending that AUTIASP is a mitigation for such forward-edge gadgetization. For the above reasons, this patch has the kernel consistently sign non-leaf functions and avoid signing leaf functions. Considering a defconfig v6.2-rc3 kernel built with LLVM 15.0.6: * The vmlinux is ~43KiB smaller: | [mark@lakrids:~/src/linux]% ls -al vmlinux-* | -rwxr-xr-x 1 mark mark 338547808 Jan 25 17:17 vmlinux-after | -rwxr-xr-x 1 mark mark 338591472 Jan 25 17:22 vmlinux-before * The resulting Image is 64KiB smaller: | [mark@lakrids:~/src/linux]% ls -al Image-* | -rwxr-xr-x 1 mark mark 32702976 Jan 25 17:17 Image-after | -rwxr-xr-x 1 mark mark 32768512 Jan 25 17:22 Image-before * There are ~400 fewer BTI gadgets: | [mark@lakrids:~/src/linux]% usekorg 12.1.0 aarch64-linux-objdump -d vmlinux-before 2> /dev/null | grep -ow 'paciasp\|bti\sc\?' | sort | uniq -c | 1219 bti c | 61982 paciasp | [mark@lakrids:~/src/linux]% usekorg 12.1.0 aarch64-linux-objdump -d vmlinux-after 2> /dev/null | grep -ow 'paciasp\|bti\sc\?' | sort | uniq -c | 10099 bti c | 52699 paciasp Which is +8880 BTIs, and -9283 PACIASPs, for -403 unnecessary BTI gadgets. While this is small relative to the total, distinguishing the two cases will make it easier to analyse and reduce this set further in future. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Mark Brown <broonie@kernel.org> Cc: Amit Daniel Kachhap <amit.kachhap@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20230131105809.991288-3-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> [resolved conflicts] Signed-off-by: Mahmoud Adam <mngyadam@amazon.com>
paniakin-aws
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Jun 24, 2025
…ress Bug report and analysis from Ding Hui. During iSCSI session logout, if another task accesses the shost ipaddress attr, we can get a KASAN UAF report like this: [ 276.942144] BUG: KASAN: use-after-free in _raw_spin_lock_bh+0x78/0xe0 [ 276.942535] Write of size 4 at addr ffff8881053b45b8 by task cat/4088 [ 276.943511] CPU: 2 PID: 4088 Comm: cat Tainted: G E 6.1.0-rc8+ #3 [ 276.943997] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020 [ 276.944470] Call Trace: [ 276.944943] <TASK> [ 276.945397] dump_stack_lvl+0x34/0x48 [ 276.945887] print_address_description.constprop.0+0x86/0x1e7 [ 276.946421] print_report+0x36/0x4f [ 276.947358] kasan_report+0xad/0x130 [ 276.948234] kasan_check_range+0x35/0x1c0 [ 276.948674] _raw_spin_lock_bh+0x78/0xe0 [ 276.949989] iscsi_sw_tcp_host_get_param+0xad/0x2e0 [iscsi_tcp] [ 276.951765] show_host_param_ISCSI_HOST_PARAM_IPADDRESS+0xe9/0x130 [scsi_transport_iscsi] [ 276.952185] dev_attr_show+0x3f/0x80 [ 276.953005] sysfs_kf_seq_show+0x1fb/0x3e0 [ 276.953401] seq_read_iter+0x402/0x1020 [ 276.954260] vfs_read+0x532/0x7b0 [ 276.955113] ksys_read+0xed/0x1c0 [ 276.955952] do_syscall_64+0x38/0x90 [ 276.956347] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 276.956769] RIP: 0033:0x7f5d3a679222 [ 276.957161] Code: c0 e9 b2 fe ff ff 50 48 8d 3d 32 c0 0b 00 e8 a5 fe 01 00 0f 1f 44 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 0f 05 <48> 3d 00 f0 ff ff 77 56 c3 0f 1f 44 00 00 48 83 ec 28 48 89 54 24 [ 276.958009] RSP: 002b:00007ffc864d16a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 276.958431] RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f5d3a679222 [ 276.958857] RDX: 0000000000020000 RSI: 00007f5d3a4fe000 RDI: 0000000000000003 [ 276.959281] RBP: 00007f5d3a4fe000 R08: 00000000ffffffff R09: 0000000000000000 [ 276.959682] R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000020000 [ 276.960126] R13: 0000000000000003 R14: 0000000000000000 R15: 0000557a26dada58 [ 276.960536] </TASK> [ 276.961357] Allocated by task 2209: [ 276.961756] kasan_save_stack+0x1e/0x40 [ 276.962170] kasan_set_track+0x21/0x30 [ 276.962557] __kasan_kmalloc+0x7e/0x90 [ 276.962923] __kmalloc+0x5b/0x140 [ 276.963308] iscsi_alloc_session+0x28/0x840 [scsi_transport_iscsi] [ 276.963712] iscsi_session_setup+0xda/0xba0 [libiscsi] [ 276.964078] iscsi_sw_tcp_session_create+0x1fd/0x330 [iscsi_tcp] [ 276.964431] iscsi_if_create_session.isra.0+0x50/0x260 [scsi_transport_iscsi] [ 276.964793] iscsi_if_recv_msg+0xc5a/0x2660 [scsi_transport_iscsi] [ 276.965153] iscsi_if_rx+0x198/0x4b0 [scsi_transport_iscsi] [ 276.965546] netlink_unicast+0x4d5/0x7b0 [ 276.965905] netlink_sendmsg+0x78d/0xc30 [ 276.966236] sock_sendmsg+0xe5/0x120 [ 276.966576] ____sys_sendmsg+0x5fe/0x860 [ 276.966923] ___sys_sendmsg+0xe0/0x170 [ 276.967300] __sys_sendmsg+0xc8/0x170 [ 276.967666] do_syscall_64+0x38/0x90 [ 276.968028] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 276.968773] Freed by task 2209: [ 276.969111] kasan_save_stack+0x1e/0x40 [ 276.969449] kasan_set_track+0x21/0x30 [ 276.969789] kasan_save_free_info+0x2a/0x50 [ 276.970146] __kasan_slab_free+0x106/0x190 [ 276.970470] __kmem_cache_free+0x133/0x270 [ 276.970816] device_release+0x98/0x210 [ 276.971145] kobject_cleanup+0x101/0x360 [ 276.971462] iscsi_session_teardown+0x3fb/0x530 [libiscsi] [ 276.971775] iscsi_sw_tcp_session_destroy+0xd8/0x130 [iscsi_tcp] [ 276.972143] iscsi_if_recv_msg+0x1bf1/0x2660 [scsi_transport_iscsi] [ 276.972485] iscsi_if_rx+0x198/0x4b0 [scsi_transport_iscsi] [ 276.972808] netlink_unicast+0x4d5/0x7b0 [ 276.973201] netlink_sendmsg+0x78d/0xc30 [ 276.973544] sock_sendmsg+0xe5/0x120 [ 276.973864] ____sys_sendmsg+0x5fe/0x860 [ 276.974248] ___sys_sendmsg+0xe0/0x170 [ 276.974583] __sys_sendmsg+0xc8/0x170 [ 276.974891] do_syscall_64+0x38/0x90 [ 276.975216] entry_SYSCALL_64_after_hwframe+0x63/0xcd We can easily reproduce by two tasks: 1. while :; do iscsiadm -m node --login; iscsiadm -m node --logout; done 2. while :; do cat \ /sys/devices/platform/host*/iscsi_host/host*/ipaddress; done iscsid | cat --------------------------------+--------------------------------------- |- iscsi_sw_tcp_session_destroy | |- iscsi_session_teardown | |- device_release | |- iscsi_session_release ||- dev_attr_show |- kfree | |- show_host_param_ | ISCSI_HOST_PARAM_IPADDRESS | |- iscsi_sw_tcp_host_get_param | |- r/w tcp_sw_host->session (UAF) |- iscsi_host_remove | |- iscsi_host_free | Fix the above bug by splitting the session removal into 2 parts: 1. removal from iSCSI class which includes sysfs and removal from host tracking. 2. freeing of session. During iscsi_tcp host and session removal we can remove the session from sysfs then remove the host from sysfs. At this point we know userspace is not accessing the kernel via sysfs so we can free the session and host. Link: https://lore.kernel.org/r/20230117193937.21244-2-michael.christie@oracle.com Signed-off-by: Mike Christie <michael.christie@oracle.com> Reviewed-by: Lee Duncan <lduncan@suse.com> Acked-by: Ding Hui <dinghui@sangfor.com.cn> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> (cherry picked from commit 6f1d64b) [Fixed to apply on 5.4] Signed-off-by: Puranjay Mohan <pjy@amazon.com>
mngyadam
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Jun 27, 2025
…ress Bug report and analysis from Ding Hui. During iSCSI session logout, if another task accesses the shost ipaddress attr, we can get a KASAN UAF report like this: [ 276.942144] BUG: KASAN: use-after-free in _raw_spin_lock_bh+0x78/0xe0 [ 276.942535] Write of size 4 at addr ffff8881053b45b8 by task cat/4088 [ 276.943511] CPU: 2 PID: 4088 Comm: cat Tainted: G E 6.1.0-rc8+ #3 [ 276.943997] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020 [ 276.944470] Call Trace: [ 276.944943] <TASK> [ 276.945397] dump_stack_lvl+0x34/0x48 [ 276.945887] print_address_description.constprop.0+0x86/0x1e7 [ 276.946421] print_report+0x36/0x4f [ 276.947358] kasan_report+0xad/0x130 [ 276.948234] kasan_check_range+0x35/0x1c0 [ 276.948674] _raw_spin_lock_bh+0x78/0xe0 [ 276.949989] iscsi_sw_tcp_host_get_param+0xad/0x2e0 [iscsi_tcp] [ 276.951765] show_host_param_ISCSI_HOST_PARAM_IPADDRESS+0xe9/0x130 [scsi_transport_iscsi] [ 276.952185] dev_attr_show+0x3f/0x80 [ 276.953005] sysfs_kf_seq_show+0x1fb/0x3e0 [ 276.953401] seq_read_iter+0x402/0x1020 [ 276.954260] vfs_read+0x532/0x7b0 [ 276.955113] ksys_read+0xed/0x1c0 [ 276.955952] do_syscall_64+0x38/0x90 [ 276.956347] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 276.956769] RIP: 0033:0x7f5d3a679222 [ 276.957161] Code: c0 e9 b2 fe ff ff 50 48 8d 3d 32 c0 0b 00 e8 a5 fe 01 00 0f 1f 44 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 0f 05 <48> 3d 00 f0 ff ff 77 56 c3 0f 1f 44 00 00 48 83 ec 28 48 89 54 24 [ 276.958009] RSP: 002b:00007ffc864d16a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 276.958431] RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f5d3a679222 [ 276.958857] RDX: 0000000000020000 RSI: 00007f5d3a4fe000 RDI: 0000000000000003 [ 276.959281] RBP: 00007f5d3a4fe000 R08: 00000000ffffffff R09: 0000000000000000 [ 276.959682] R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000020000 [ 276.960126] R13: 0000000000000003 R14: 0000000000000000 R15: 0000557a26dada58 [ 276.960536] </TASK> [ 276.961357] Allocated by task 2209: [ 276.961756] kasan_save_stack+0x1e/0x40 [ 276.962170] kasan_set_track+0x21/0x30 [ 276.962557] __kasan_kmalloc+0x7e/0x90 [ 276.962923] __kmalloc+0x5b/0x140 [ 276.963308] iscsi_alloc_session+0x28/0x840 [scsi_transport_iscsi] [ 276.963712] iscsi_session_setup+0xda/0xba0 [libiscsi] [ 276.964078] iscsi_sw_tcp_session_create+0x1fd/0x330 [iscsi_tcp] [ 276.964431] iscsi_if_create_session.isra.0+0x50/0x260 [scsi_transport_iscsi] [ 276.964793] iscsi_if_recv_msg+0xc5a/0x2660 [scsi_transport_iscsi] [ 276.965153] iscsi_if_rx+0x198/0x4b0 [scsi_transport_iscsi] [ 276.965546] netlink_unicast+0x4d5/0x7b0 [ 276.965905] netlink_sendmsg+0x78d/0xc30 [ 276.966236] sock_sendmsg+0xe5/0x120 [ 276.966576] ____sys_sendmsg+0x5fe/0x860 [ 276.966923] ___sys_sendmsg+0xe0/0x170 [ 276.967300] __sys_sendmsg+0xc8/0x170 [ 276.967666] do_syscall_64+0x38/0x90 [ 276.968028] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 276.968773] Freed by task 2209: [ 276.969111] kasan_save_stack+0x1e/0x40 [ 276.969449] kasan_set_track+0x21/0x30 [ 276.969789] kasan_save_free_info+0x2a/0x50 [ 276.970146] __kasan_slab_free+0x106/0x190 [ 276.970470] __kmem_cache_free+0x133/0x270 [ 276.970816] device_release+0x98/0x210 [ 276.971145] kobject_cleanup+0x101/0x360 [ 276.971462] iscsi_session_teardown+0x3fb/0x530 [libiscsi] [ 276.971775] iscsi_sw_tcp_session_destroy+0xd8/0x130 [iscsi_tcp] [ 276.972143] iscsi_if_recv_msg+0x1bf1/0x2660 [scsi_transport_iscsi] [ 276.972485] iscsi_if_rx+0x198/0x4b0 [scsi_transport_iscsi] [ 276.972808] netlink_unicast+0x4d5/0x7b0 [ 276.973201] netlink_sendmsg+0x78d/0xc30 [ 276.973544] sock_sendmsg+0xe5/0x120 [ 276.973864] ____sys_sendmsg+0x5fe/0x860 [ 276.974248] ___sys_sendmsg+0xe0/0x170 [ 276.974583] __sys_sendmsg+0xc8/0x170 [ 276.974891] do_syscall_64+0x38/0x90 [ 276.975216] entry_SYSCALL_64_after_hwframe+0x63/0xcd We can easily reproduce by two tasks: 1. while :; do iscsiadm -m node --login; iscsiadm -m node --logout; done 2. while :; do cat \ /sys/devices/platform/host*/iscsi_host/host*/ipaddress; done iscsid | cat --------------------------------+--------------------------------------- |- iscsi_sw_tcp_session_destroy | |- iscsi_session_teardown | |- device_release | |- iscsi_session_release ||- dev_attr_show |- kfree | |- show_host_param_ | ISCSI_HOST_PARAM_IPADDRESS | |- iscsi_sw_tcp_host_get_param | |- r/w tcp_sw_host->session (UAF) |- iscsi_host_remove | |- iscsi_host_free | Fix the above bug by splitting the session removal into 2 parts: 1. removal from iSCSI class which includes sysfs and removal from host tracking. 2. freeing of session. During iscsi_tcp host and session removal we can remove the session from sysfs then remove the host from sysfs. At this point we know userspace is not accessing the kernel via sysfs so we can free the session and host. Link: https://lore.kernel.org/r/20230117193937.21244-2-michael.christie@oracle.com Signed-off-by: Mike Christie <michael.christie@oracle.com> Reviewed-by: Lee Duncan <lduncan@suse.com> Acked-by: Ding Hui <dinghui@sangfor.com.cn> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> (cherry picked from commit 6f1d64b) [fixed to apply on 4.14] Signed-off-by: Puranjay Mohan <pjy@amazon.com>
mngyadam
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that referenced
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Jun 27, 2025
…ress Bug report and analysis from Ding Hui. During iSCSI session logout, if another task accesses the shost ipaddress attr, we can get a KASAN UAF report like this: [ 276.942144] BUG: KASAN: use-after-free in _raw_spin_lock_bh+0x78/0xe0 [ 276.942535] Write of size 4 at addr ffff8881053b45b8 by task cat/4088 [ 276.943511] CPU: 2 PID: 4088 Comm: cat Tainted: G E 6.1.0-rc8+ #3 [ 276.943997] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020 [ 276.944470] Call Trace: [ 276.944943] <TASK> [ 276.945397] dump_stack_lvl+0x34/0x48 [ 276.945887] print_address_description.constprop.0+0x86/0x1e7 [ 276.946421] print_report+0x36/0x4f [ 276.947358] kasan_report+0xad/0x130 [ 276.948234] kasan_check_range+0x35/0x1c0 [ 276.948674] _raw_spin_lock_bh+0x78/0xe0 [ 276.949989] iscsi_sw_tcp_host_get_param+0xad/0x2e0 [iscsi_tcp] [ 276.951765] show_host_param_ISCSI_HOST_PARAM_IPADDRESS+0xe9/0x130 [scsi_transport_iscsi] [ 276.952185] dev_attr_show+0x3f/0x80 [ 276.953005] sysfs_kf_seq_show+0x1fb/0x3e0 [ 276.953401] seq_read_iter+0x402/0x1020 [ 276.954260] vfs_read+0x532/0x7b0 [ 276.955113] ksys_read+0xed/0x1c0 [ 276.955952] do_syscall_64+0x38/0x90 [ 276.956347] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 276.956769] RIP: 0033:0x7f5d3a679222 [ 276.957161] Code: c0 e9 b2 fe ff ff 50 48 8d 3d 32 c0 0b 00 e8 a5 fe 01 00 0f 1f 44 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 0f 05 <48> 3d 00 f0 ff ff 77 56 c3 0f 1f 44 00 00 48 83 ec 28 48 89 54 24 [ 276.958009] RSP: 002b:00007ffc864d16a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 276.958431] RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f5d3a679222 [ 276.958857] RDX: 0000000000020000 RSI: 00007f5d3a4fe000 RDI: 0000000000000003 [ 276.959281] RBP: 00007f5d3a4fe000 R08: 00000000ffffffff R09: 0000000000000000 [ 276.959682] R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000020000 [ 276.960126] R13: 0000000000000003 R14: 0000000000000000 R15: 0000557a26dada58 [ 276.960536] </TASK> [ 276.961357] Allocated by task 2209: [ 276.961756] kasan_save_stack+0x1e/0x40 [ 276.962170] kasan_set_track+0x21/0x30 [ 276.962557] __kasan_kmalloc+0x7e/0x90 [ 276.962923] __kmalloc+0x5b/0x140 [ 276.963308] iscsi_alloc_session+0x28/0x840 [scsi_transport_iscsi] [ 276.963712] iscsi_session_setup+0xda/0xba0 [libiscsi] [ 276.964078] iscsi_sw_tcp_session_create+0x1fd/0x330 [iscsi_tcp] [ 276.964431] iscsi_if_create_session.isra.0+0x50/0x260 [scsi_transport_iscsi] [ 276.964793] iscsi_if_recv_msg+0xc5a/0x2660 [scsi_transport_iscsi] [ 276.965153] iscsi_if_rx+0x198/0x4b0 [scsi_transport_iscsi] [ 276.965546] netlink_unicast+0x4d5/0x7b0 [ 276.965905] netlink_sendmsg+0x78d/0xc30 [ 276.966236] sock_sendmsg+0xe5/0x120 [ 276.966576] ____sys_sendmsg+0x5fe/0x860 [ 276.966923] ___sys_sendmsg+0xe0/0x170 [ 276.967300] __sys_sendmsg+0xc8/0x170 [ 276.967666] do_syscall_64+0x38/0x90 [ 276.968028] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 276.968773] Freed by task 2209: [ 276.969111] kasan_save_stack+0x1e/0x40 [ 276.969449] kasan_set_track+0x21/0x30 [ 276.969789] kasan_save_free_info+0x2a/0x50 [ 276.970146] __kasan_slab_free+0x106/0x190 [ 276.970470] __kmem_cache_free+0x133/0x270 [ 276.970816] device_release+0x98/0x210 [ 276.971145] kobject_cleanup+0x101/0x360 [ 276.971462] iscsi_session_teardown+0x3fb/0x530 [libiscsi] [ 276.971775] iscsi_sw_tcp_session_destroy+0xd8/0x130 [iscsi_tcp] [ 276.972143] iscsi_if_recv_msg+0x1bf1/0x2660 [scsi_transport_iscsi] [ 276.972485] iscsi_if_rx+0x198/0x4b0 [scsi_transport_iscsi] [ 276.972808] netlink_unicast+0x4d5/0x7b0 [ 276.973201] netlink_sendmsg+0x78d/0xc30 [ 276.973544] sock_sendmsg+0xe5/0x120 [ 276.973864] ____sys_sendmsg+0x5fe/0x860 [ 276.974248] ___sys_sendmsg+0xe0/0x170 [ 276.974583] __sys_sendmsg+0xc8/0x170 [ 276.974891] do_syscall_64+0x38/0x90 [ 276.975216] entry_SYSCALL_64_after_hwframe+0x63/0xcd We can easily reproduce by two tasks: 1. while :; do iscsiadm -m node --login; iscsiadm -m node --logout; done 2. while :; do cat \ /sys/devices/platform/host*/iscsi_host/host*/ipaddress; done iscsid | cat --------------------------------+--------------------------------------- |- iscsi_sw_tcp_session_destroy | |- iscsi_session_teardown | |- device_release | |- iscsi_session_release ||- dev_attr_show |- kfree | |- show_host_param_ | ISCSI_HOST_PARAM_IPADDRESS | |- iscsi_sw_tcp_host_get_param | |- r/w tcp_sw_host->session (UAF) |- iscsi_host_remove | |- iscsi_host_free | Fix the above bug by splitting the session removal into 2 parts: 1. removal from iSCSI class which includes sysfs and removal from host tracking. 2. freeing of session. During iscsi_tcp host and session removal we can remove the session from sysfs then remove the host from sysfs. At this point we know userspace is not accessing the kernel via sysfs so we can free the session and host. Link: https://lore.kernel.org/r/20230117193937.21244-2-michael.christie@oracle.com Signed-off-by: Mike Christie <michael.christie@oracle.com> Reviewed-by: Lee Duncan <lduncan@suse.com> Acked-by: Ding Hui <dinghui@sangfor.com.cn> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> (cherry picked from commit 6f1d64b) [Fixed to apply on 5.4] Signed-off-by: Puranjay Mohan <pjy@amazon.com>
mngyadam
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Jun 27, 2025
Commit c68cf52 upstream Currently, when CONFIG_ARM64_PTR_AUTH_KERNEL=y (and CONFIG_UNWIND_PATCH_PAC_INTO_SCS=n), we enable pointer authentication for all functions, including leaf functions. This isn't necessary, and is unfortunate for a few reasons: * Any PACIASP instruction is implicitly a `BTI C` landing pad, and forcing the addition of a PACIASP in every function introduces a larger set of BTI gadgets than is necessary. * The PACIASP and AUTIASP instructions make leaf functions larger than necessary, bloating the kernel Image. For a defconfig v6.2-rc3 kernel, this appears to add ~64KiB relative to not signing leaf functions, which is unfortunate but not entirely onerous. * The PACIASP and AUTIASP instructions potentially make leaf functions more expensive in terms of performance and/or power. For many trivial leaf functions, this is clearly unnecessary, e.g. | <arch_local_save_flags>: | d503233f paciasp | d53b4220 mrs x0, daif | d50323bf autiasp | d65f03c0 ret | <calibration_delay_done>: | d503233f paciasp | d50323bf autiasp | d65f03c0 ret | d503201f nop * When CONFIG_UNWIND_PATCH_PAC_INTO_SCS=y we disable pointer authentication for leaf functions, so clearly this is not functionally necessary, indicates we have an inconsistent threat model, and convolutes the Makefile logic. We've used pointer authentication in leaf functions since the introduction of in-kernel pointer authentication in commit: 74afda4 ("arm64: compile the kernel with ptrauth return address signing") ... but at the time we had no rationale for signing leaf functions. Subsequently, we considered avoiding signing leaf functions: https://lore.kernel.org/linux-arm-kernel/1586856741-26839-1-git-send-email-amit.kachhap@arm.com/ https://lore.kernel.org/linux-arm-kernel/1588149371-20310-1-git-send-email-amit.kachhap@arm.com/ ... however at the time we didn't have an abundance of reasons to avoid signing leaf functions as above (e.g. the BTI case), we had no hardware to make performance measurements, and it was reasoned that this gave some level of protection against a limited set of code-reuse gadgets which would fall through to a RET. We documented this in commit: 717b938 ("arm64: Document why we enable PAC support for leaf functions") Notably, this was before we supported any forward-edge CFI scheme (e.g. Arm BTI, or Clang CFI/kCFI), which would prevent jumping into the middle of a function. In addition, even with signing forced for leaf functions, AUTIASP may be placed before a number of instructions which might constitute such a gadget, e.g. | <user_regs_reset_single_step>: | f9400022 ldr x2, [x1] | d503233f paciasp | d50323bf autiasp | f9408401 ldr x1, [x0, #264] | 720b005f tst w2, #0x200000 | b26b0022 orr x2, x1, #0x200000 | 926af821 and x1, x1, #0xffffffffffdfffff | 9a820021 csel x1, x1, x2, eq // eq = none | f9008401 str x1, [x0, #264] | d65f03c0 ret | <fpsimd_cpu_dead>: | 2a0003e3 mov w3, w0 | 9000ff42 adrp x2, ffff800009ffd000 <xen_dynamic_chip+0x48> | 9120e042 add x2, x2, #0x838 | 52800000 mov w0, #0x0 // #0 | d503233f paciasp | f000d041 adrp x1, ffff800009a20000 <this_cpu_vector> | d50323bf autiasp | 9102c021 add x1, x1, #0xb0 | f8635842 ldr x2, [x2, w3, uxtw #3] | f821685f str xzr, [x2, x1] | d65f03c0 ret | d503201f nop So generally, trying to use AUTIASP to detect such gadgetization is not robust, and this is dealt with far better by forward-edge CFI (which is designed to prevent such cases). We should bite the bullet and stop pretending that AUTIASP is a mitigation for such forward-edge gadgetization. For the above reasons, this patch has the kernel consistently sign non-leaf functions and avoid signing leaf functions. Considering a defconfig v6.2-rc3 kernel built with LLVM 15.0.6: * The vmlinux is ~43KiB smaller: | [mark@lakrids:~/src/linux]% ls -al vmlinux-* | -rwxr-xr-x 1 mark mark 338547808 Jan 25 17:17 vmlinux-after | -rwxr-xr-x 1 mark mark 338591472 Jan 25 17:22 vmlinux-before * The resulting Image is 64KiB smaller: | [mark@lakrids:~/src/linux]% ls -al Image-* | -rwxr-xr-x 1 mark mark 32702976 Jan 25 17:17 Image-after | -rwxr-xr-x 1 mark mark 32768512 Jan 25 17:22 Image-before * There are ~400 fewer BTI gadgets: | [mark@lakrids:~/src/linux]% usekorg 12.1.0 aarch64-linux-objdump -d vmlinux-before 2> /dev/null | grep -ow 'paciasp\|bti\sc\?' | sort | uniq -c | 1219 bti c | 61982 paciasp | [mark@lakrids:~/src/linux]% usekorg 12.1.0 aarch64-linux-objdump -d vmlinux-after 2> /dev/null | grep -ow 'paciasp\|bti\sc\?' | sort | uniq -c | 10099 bti c | 52699 paciasp Which is +8880 BTIs, and -9283 PACIASPs, for -403 unnecessary BTI gadgets. While this is small relative to the total, distinguishing the two cases will make it easier to analyse and reduce this set further in future. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Mark Brown <broonie@kernel.org> Cc: Amit Daniel Kachhap <amit.kachhap@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20230131105809.991288-3-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> [resolved conflicts] Signed-off-by: Mahmoud Adam <mngyadam@amazon.com>
mngyadam
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Jun 27, 2025
…ress Bug report and analysis from Ding Hui. During iSCSI session logout, if another task accesses the shost ipaddress attr, we can get a KASAN UAF report like this: [ 276.942144] BUG: KASAN: use-after-free in _raw_spin_lock_bh+0x78/0xe0 [ 276.942535] Write of size 4 at addr ffff8881053b45b8 by task cat/4088 [ 276.943511] CPU: 2 PID: 4088 Comm: cat Tainted: G E 6.1.0-rc8+ #3 [ 276.943997] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020 [ 276.944470] Call Trace: [ 276.944943] <TASK> [ 276.945397] dump_stack_lvl+0x34/0x48 [ 276.945887] print_address_description.constprop.0+0x86/0x1e7 [ 276.946421] print_report+0x36/0x4f [ 276.947358] kasan_report+0xad/0x130 [ 276.948234] kasan_check_range+0x35/0x1c0 [ 276.948674] _raw_spin_lock_bh+0x78/0xe0 [ 276.949989] iscsi_sw_tcp_host_get_param+0xad/0x2e0 [iscsi_tcp] [ 276.951765] show_host_param_ISCSI_HOST_PARAM_IPADDRESS+0xe9/0x130 [scsi_transport_iscsi] [ 276.952185] dev_attr_show+0x3f/0x80 [ 276.953005] sysfs_kf_seq_show+0x1fb/0x3e0 [ 276.953401] seq_read_iter+0x402/0x1020 [ 276.954260] vfs_read+0x532/0x7b0 [ 276.955113] ksys_read+0xed/0x1c0 [ 276.955952] do_syscall_64+0x38/0x90 [ 276.956347] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 276.956769] RIP: 0033:0x7f5d3a679222 [ 276.957161] Code: c0 e9 b2 fe ff ff 50 48 8d 3d 32 c0 0b 00 e8 a5 fe 01 00 0f 1f 44 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 0f 05 <48> 3d 00 f0 ff ff 77 56 c3 0f 1f 44 00 00 48 83 ec 28 48 89 54 24 [ 276.958009] RSP: 002b:00007ffc864d16a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 276.958431] RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f5d3a679222 [ 276.958857] RDX: 0000000000020000 RSI: 00007f5d3a4fe000 RDI: 0000000000000003 [ 276.959281] RBP: 00007f5d3a4fe000 R08: 00000000ffffffff R09: 0000000000000000 [ 276.959682] R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000020000 [ 276.960126] R13: 0000000000000003 R14: 0000000000000000 R15: 0000557a26dada58 [ 276.960536] </TASK> [ 276.961357] Allocated by task 2209: [ 276.961756] kasan_save_stack+0x1e/0x40 [ 276.962170] kasan_set_track+0x21/0x30 [ 276.962557] __kasan_kmalloc+0x7e/0x90 [ 276.962923] __kmalloc+0x5b/0x140 [ 276.963308] iscsi_alloc_session+0x28/0x840 [scsi_transport_iscsi] [ 276.963712] iscsi_session_setup+0xda/0xba0 [libiscsi] [ 276.964078] iscsi_sw_tcp_session_create+0x1fd/0x330 [iscsi_tcp] [ 276.964431] iscsi_if_create_session.isra.0+0x50/0x260 [scsi_transport_iscsi] [ 276.964793] iscsi_if_recv_msg+0xc5a/0x2660 [scsi_transport_iscsi] [ 276.965153] iscsi_if_rx+0x198/0x4b0 [scsi_transport_iscsi] [ 276.965546] netlink_unicast+0x4d5/0x7b0 [ 276.965905] netlink_sendmsg+0x78d/0xc30 [ 276.966236] sock_sendmsg+0xe5/0x120 [ 276.966576] ____sys_sendmsg+0x5fe/0x860 [ 276.966923] ___sys_sendmsg+0xe0/0x170 [ 276.967300] __sys_sendmsg+0xc8/0x170 [ 276.967666] do_syscall_64+0x38/0x90 [ 276.968028] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 276.968773] Freed by task 2209: [ 276.969111] kasan_save_stack+0x1e/0x40 [ 276.969449] kasan_set_track+0x21/0x30 [ 276.969789] kasan_save_free_info+0x2a/0x50 [ 276.970146] __kasan_slab_free+0x106/0x190 [ 276.970470] __kmem_cache_free+0x133/0x270 [ 276.970816] device_release+0x98/0x210 [ 276.971145] kobject_cleanup+0x101/0x360 [ 276.971462] iscsi_session_teardown+0x3fb/0x530 [libiscsi] [ 276.971775] iscsi_sw_tcp_session_destroy+0xd8/0x130 [iscsi_tcp] [ 276.972143] iscsi_if_recv_msg+0x1bf1/0x2660 [scsi_transport_iscsi] [ 276.972485] iscsi_if_rx+0x198/0x4b0 [scsi_transport_iscsi] [ 276.972808] netlink_unicast+0x4d5/0x7b0 [ 276.973201] netlink_sendmsg+0x78d/0xc30 [ 276.973544] sock_sendmsg+0xe5/0x120 [ 276.973864] ____sys_sendmsg+0x5fe/0x860 [ 276.974248] ___sys_sendmsg+0xe0/0x170 [ 276.974583] __sys_sendmsg+0xc8/0x170 [ 276.974891] do_syscall_64+0x38/0x90 [ 276.975216] entry_SYSCALL_64_after_hwframe+0x63/0xcd We can easily reproduce by two tasks: 1. while :; do iscsiadm -m node --login; iscsiadm -m node --logout; done 2. while :; do cat \ /sys/devices/platform/host*/iscsi_host/host*/ipaddress; done iscsid | cat --------------------------------+--------------------------------------- |- iscsi_sw_tcp_session_destroy | |- iscsi_session_teardown | |- device_release | |- iscsi_session_release ||- dev_attr_show |- kfree | |- show_host_param_ | ISCSI_HOST_PARAM_IPADDRESS | |- iscsi_sw_tcp_host_get_param | |- r/w tcp_sw_host->session (UAF) |- iscsi_host_remove | |- iscsi_host_free | Fix the above bug by splitting the session removal into 2 parts: 1. removal from iSCSI class which includes sysfs and removal from host tracking. 2. freeing of session. During iscsi_tcp host and session removal we can remove the session from sysfs then remove the host from sysfs. At this point we know userspace is not accessing the kernel via sysfs so we can free the session and host. Link: https://lore.kernel.org/r/20230117193937.21244-2-michael.christie@oracle.com Signed-off-by: Mike Christie <michael.christie@oracle.com> Reviewed-by: Lee Duncan <lduncan@suse.com> Acked-by: Ding Hui <dinghui@sangfor.com.cn> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> (cherry picked from commit 6f1d64b) [Fixed to apply on 5.10] Signed-off-by: Puranjay Mohan <pjy@amazon.com>
mngyadam
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Jun 27, 2025
Commit c68cf52 upstream Currently, when CONFIG_ARM64_PTR_AUTH_KERNEL=y (and CONFIG_UNWIND_PATCH_PAC_INTO_SCS=n), we enable pointer authentication for all functions, including leaf functions. This isn't necessary, and is unfortunate for a few reasons: * Any PACIASP instruction is implicitly a `BTI C` landing pad, and forcing the addition of a PACIASP in every function introduces a larger set of BTI gadgets than is necessary. * The PACIASP and AUTIASP instructions make leaf functions larger than necessary, bloating the kernel Image. For a defconfig v6.2-rc3 kernel, this appears to add ~64KiB relative to not signing leaf functions, which is unfortunate but not entirely onerous. * The PACIASP and AUTIASP instructions potentially make leaf functions more expensive in terms of performance and/or power. For many trivial leaf functions, this is clearly unnecessary, e.g. | <arch_local_save_flags>: | d503233f paciasp | d53b4220 mrs x0, daif | d50323bf autiasp | d65f03c0 ret | <calibration_delay_done>: | d503233f paciasp | d50323bf autiasp | d65f03c0 ret | d503201f nop * When CONFIG_UNWIND_PATCH_PAC_INTO_SCS=y we disable pointer authentication for leaf functions, so clearly this is not functionally necessary, indicates we have an inconsistent threat model, and convolutes the Makefile logic. We've used pointer authentication in leaf functions since the introduction of in-kernel pointer authentication in commit: 74afda4 ("arm64: compile the kernel with ptrauth return address signing") ... but at the time we had no rationale for signing leaf functions. Subsequently, we considered avoiding signing leaf functions: https://lore.kernel.org/linux-arm-kernel/1586856741-26839-1-git-send-email-amit.kachhap@arm.com/ https://lore.kernel.org/linux-arm-kernel/1588149371-20310-1-git-send-email-amit.kachhap@arm.com/ ... however at the time we didn't have an abundance of reasons to avoid signing leaf functions as above (e.g. the BTI case), we had no hardware to make performance measurements, and it was reasoned that this gave some level of protection against a limited set of code-reuse gadgets which would fall through to a RET. We documented this in commit: 717b938 ("arm64: Document why we enable PAC support for leaf functions") Notably, this was before we supported any forward-edge CFI scheme (e.g. Arm BTI, or Clang CFI/kCFI), which would prevent jumping into the middle of a function. In addition, even with signing forced for leaf functions, AUTIASP may be placed before a number of instructions which might constitute such a gadget, e.g. | <user_regs_reset_single_step>: | f9400022 ldr x2, [x1] | d503233f paciasp | d50323bf autiasp | f9408401 ldr x1, [x0, #264] | 720b005f tst w2, #0x200000 | b26b0022 orr x2, x1, #0x200000 | 926af821 and x1, x1, #0xffffffffffdfffff | 9a820021 csel x1, x1, x2, eq // eq = none | f9008401 str x1, [x0, #264] | d65f03c0 ret | <fpsimd_cpu_dead>: | 2a0003e3 mov w3, w0 | 9000ff42 adrp x2, ffff800009ffd000 <xen_dynamic_chip+0x48> | 9120e042 add x2, x2, #0x838 | 52800000 mov w0, #0x0 // #0 | d503233f paciasp | f000d041 adrp x1, ffff800009a20000 <this_cpu_vector> | d50323bf autiasp | 9102c021 add x1, x1, #0xb0 | f8635842 ldr x2, [x2, w3, uxtw #3] | f821685f str xzr, [x2, x1] | d65f03c0 ret | d503201f nop So generally, trying to use AUTIASP to detect such gadgetization is not robust, and this is dealt with far better by forward-edge CFI (which is designed to prevent such cases). We should bite the bullet and stop pretending that AUTIASP is a mitigation for such forward-edge gadgetization. For the above reasons, this patch has the kernel consistently sign non-leaf functions and avoid signing leaf functions. Considering a defconfig v6.2-rc3 kernel built with LLVM 15.0.6: * The vmlinux is ~43KiB smaller: | [mark@lakrids:~/src/linux]% ls -al vmlinux-* | -rwxr-xr-x 1 mark mark 338547808 Jan 25 17:17 vmlinux-after | -rwxr-xr-x 1 mark mark 338591472 Jan 25 17:22 vmlinux-before * The resulting Image is 64KiB smaller: | [mark@lakrids:~/src/linux]% ls -al Image-* | -rwxr-xr-x 1 mark mark 32702976 Jan 25 17:17 Image-after | -rwxr-xr-x 1 mark mark 32768512 Jan 25 17:22 Image-before * There are ~400 fewer BTI gadgets: | [mark@lakrids:~/src/linux]% usekorg 12.1.0 aarch64-linux-objdump -d vmlinux-before 2> /dev/null | grep -ow 'paciasp\|bti\sc\?' | sort | uniq -c | 1219 bti c | 61982 paciasp | [mark@lakrids:~/src/linux]% usekorg 12.1.0 aarch64-linux-objdump -d vmlinux-after 2> /dev/null | grep -ow 'paciasp\|bti\sc\?' | sort | uniq -c | 10099 bti c | 52699 paciasp Which is +8880 BTIs, and -9283 PACIASPs, for -403 unnecessary BTI gadgets. While this is small relative to the total, distinguishing the two cases will make it easier to analyse and reduce this set further in future. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Mark Brown <broonie@kernel.org> Cc: Amit Daniel Kachhap <amit.kachhap@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20230131105809.991288-3-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> [resolved conflicts] Signed-off-by: Mahmoud Adam <mngyadam@amazon.com>
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Jun 27, 2025
Commit c68cf52 upstream Currently, when CONFIG_ARM64_PTR_AUTH_KERNEL=y (and CONFIG_UNWIND_PATCH_PAC_INTO_SCS=n), we enable pointer authentication for all functions, including leaf functions. This isn't necessary, and is unfortunate for a few reasons: * Any PACIASP instruction is implicitly a `BTI C` landing pad, and forcing the addition of a PACIASP in every function introduces a larger set of BTI gadgets than is necessary. * The PACIASP and AUTIASP instructions make leaf functions larger than necessary, bloating the kernel Image. For a defconfig v6.2-rc3 kernel, this appears to add ~64KiB relative to not signing leaf functions, which is unfortunate but not entirely onerous. * The PACIASP and AUTIASP instructions potentially make leaf functions more expensive in terms of performance and/or power. For many trivial leaf functions, this is clearly unnecessary, e.g. | <arch_local_save_flags>: | d503233f paciasp | d53b4220 mrs x0, daif | d50323bf autiasp | d65f03c0 ret | <calibration_delay_done>: | d503233f paciasp | d50323bf autiasp | d65f03c0 ret | d503201f nop * When CONFIG_UNWIND_PATCH_PAC_INTO_SCS=y we disable pointer authentication for leaf functions, so clearly this is not functionally necessary, indicates we have an inconsistent threat model, and convolutes the Makefile logic. We've used pointer authentication in leaf functions since the introduction of in-kernel pointer authentication in commit: 74afda4 ("arm64: compile the kernel with ptrauth return address signing") ... but at the time we had no rationale for signing leaf functions. Subsequently, we considered avoiding signing leaf functions: https://lore.kernel.org/linux-arm-kernel/1586856741-26839-1-git-send-email-amit.kachhap@arm.com/ https://lore.kernel.org/linux-arm-kernel/1588149371-20310-1-git-send-email-amit.kachhap@arm.com/ ... however at the time we didn't have an abundance of reasons to avoid signing leaf functions as above (e.g. the BTI case), we had no hardware to make performance measurements, and it was reasoned that this gave some level of protection against a limited set of code-reuse gadgets which would fall through to a RET. We documented this in commit: 717b938 ("arm64: Document why we enable PAC support for leaf functions") Notably, this was before we supported any forward-edge CFI scheme (e.g. Arm BTI, or Clang CFI/kCFI), which would prevent jumping into the middle of a function. In addition, even with signing forced for leaf functions, AUTIASP may be placed before a number of instructions which might constitute such a gadget, e.g. | <user_regs_reset_single_step>: | f9400022 ldr x2, [x1] | d503233f paciasp | d50323bf autiasp | f9408401 ldr x1, [x0, #264] | 720b005f tst w2, #0x200000 | b26b0022 orr x2, x1, #0x200000 | 926af821 and x1, x1, #0xffffffffffdfffff | 9a820021 csel x1, x1, x2, eq // eq = none | f9008401 str x1, [x0, #264] | d65f03c0 ret | <fpsimd_cpu_dead>: | 2a0003e3 mov w3, w0 | 9000ff42 adrp x2, ffff800009ffd000 <xen_dynamic_chip+0x48> | 9120e042 add x2, x2, #0x838 | 52800000 mov w0, #0x0 // #0 | d503233f paciasp | f000d041 adrp x1, ffff800009a20000 <this_cpu_vector> | d50323bf autiasp | 9102c021 add x1, x1, #0xb0 | f8635842 ldr x2, [x2, w3, uxtw #3] | f821685f str xzr, [x2, x1] | d65f03c0 ret | d503201f nop So generally, trying to use AUTIASP to detect such gadgetization is not robust, and this is dealt with far better by forward-edge CFI (which is designed to prevent such cases). We should bite the bullet and stop pretending that AUTIASP is a mitigation for such forward-edge gadgetization. For the above reasons, this patch has the kernel consistently sign non-leaf functions and avoid signing leaf functions. Considering a defconfig v6.2-rc3 kernel built with LLVM 15.0.6: * The vmlinux is ~43KiB smaller: | [mark@lakrids:~/src/linux]% ls -al vmlinux-* | -rwxr-xr-x 1 mark mark 338547808 Jan 25 17:17 vmlinux-after | -rwxr-xr-x 1 mark mark 338591472 Jan 25 17:22 vmlinux-before * The resulting Image is 64KiB smaller: | [mark@lakrids:~/src/linux]% ls -al Image-* | -rwxr-xr-x 1 mark mark 32702976 Jan 25 17:17 Image-after | -rwxr-xr-x 1 mark mark 32768512 Jan 25 17:22 Image-before * There are ~400 fewer BTI gadgets: | [mark@lakrids:~/src/linux]% usekorg 12.1.0 aarch64-linux-objdump -d vmlinux-before 2> /dev/null | grep -ow 'paciasp\|bti\sc\?' | sort | uniq -c | 1219 bti c | 61982 paciasp | [mark@lakrids:~/src/linux]% usekorg 12.1.0 aarch64-linux-objdump -d vmlinux-after 2> /dev/null | grep -ow 'paciasp\|bti\sc\?' | sort | uniq -c | 10099 bti c | 52699 paciasp Which is +8880 BTIs, and -9283 PACIASPs, for -403 unnecessary BTI gadgets. While this is small relative to the total, distinguishing the two cases will make it easier to analyse and reduce this set further in future. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Mark Brown <broonie@kernel.org> Cc: Amit Daniel Kachhap <amit.kachhap@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20230131105809.991288-3-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> [resolved conflicts] Signed-off-by: Mahmoud Adam <mngyadam@amazon.com>
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[ Upstream commit eedf3e3 ] ACPICA commit 1c28da2242783579d59767617121035dafba18c3 This was originally done in NetBSD: NetBSD/src@b69d1ac and is the correct alternative to the smattering of `memcpy`s I previously contributed to this repository. This also sidesteps the newly strict checks added in UBSAN: llvm/llvm-project@7926744 Before this change we see the following UBSAN stack trace in Fuchsia: #0 0x000021afcfdeca5e in acpi_rs_get_address_common(struct acpi_resource*, union aml_resource*) ../../third_party/acpica/source/components/resources/rsaddr.c:329 <platform-bus-x86.so>+0x6aca5e #1.2 0x000021982bc4af3c in ubsan_get_stack_trace() compiler-rt/lib/ubsan/ubsan_diag.cpp:41 <libclang_rt.asan.so>+0x41f3c #1.1 0x000021982bc4af3c in maybe_print_stack_trace() compiler-rt/lib/ubsan/ubsan_diag.cpp:51 <libclang_rt.asan.so>+0x41f3c #1 0x000021982bc4af3c in ~scoped_report() compiler-rt/lib/ubsan/ubsan_diag.cpp:395 <libclang_rt.asan.so>+0x41f3c #2 0x000021982bc4bb6f in handletype_mismatch_impl() compiler-rt/lib/ubsan/ubsan_handlers.cpp:137 <libclang_rt.asan.so>+0x42b6f #3 0x000021982bc4b723 in __ubsan_handle_type_mismatch_v1 compiler-rt/lib/ubsan/ubsan_handlers.cpp:142 <libclang_rt.asan.so>+0x42723 #4 0x000021afcfdeca5e in acpi_rs_get_address_common(struct acpi_resource*, union aml_resource*) ../../third_party/acpica/source/components/resources/rsaddr.c:329 <platform-bus-x86.so>+0x6aca5e #5 0x000021afcfdf2089 in acpi_rs_convert_aml_to_resource(struct acpi_resource*, union aml_resource*, struct acpi_rsconvert_info*) ../../third_party/acpica/source/components/resources/rsmisc.c:355 <platform-bus-x86.so>+0x6b2089 gregkh#6 0x000021afcfded169 in acpi_rs_convert_aml_to_resources(u8*, u32, u32, u8, void**) ../../third_party/acpica/source/components/resources/rslist.c:137 <platform-bus-x86.so>+0x6ad169 gregkh#7 0x000021afcfe2d24a in acpi_ut_walk_aml_resources(struct acpi_walk_state*, u8*, acpi_size, acpi_walk_aml_callback, void**) ../../third_party/acpica/source/components/utilities/utresrc.c:237 <platform-bus-x86.so>+0x6ed24a gregkh#8 0x000021afcfde66b7 in acpi_rs_create_resource_list(union acpi_operand_object*, struct acpi_buffer*) ../../third_party/acpica/source/components/resources/rscreate.c:199 <platform-bus-x86.so>+0x6a66b7 gregkh#9 0x000021afcfdf6979 in acpi_rs_get_method_data(acpi_handle, const char*, struct acpi_buffer*) ../../third_party/acpica/source/components/resources/rsutils.c:770 <platform-bus-x86.so>+0x6b6979 gregkh#10 0x000021afcfdf708f in acpi_walk_resources(acpi_handle, char*, acpi_walk_resource_callback, void*) ../../third_party/acpica/source/components/resources/rsxface.c:731 <platform-bus-x86.so>+0x6b708f gregkh#11 0x000021afcfa95dcf in acpi::acpi_impl::walk_resources(acpi::acpi_impl*, acpi_handle, const char*, acpi::Acpi::resources_callable) ../../src/devices/board/lib/acpi/acpi-impl.cc:41 <platform-bus-x86.so>+0x355dcf gregkh#12 0x000021afcfaa8278 in acpi::device_builder::gather_resources(acpi::device_builder*, acpi::Acpi*, fidl::any_arena&, acpi::Manager*, acpi::device_builder::gather_resources_callback) ../../src/devices/board/lib/acpi/device-builder.cc:84 <platform-bus-x86.so>+0x368278 gregkh#13 0x000021afcfbddb87 in acpi::Manager::configure_discovered_devices(acpi::Manager*) ../../src/devices/board/lib/acpi/manager.cc:75 <platform-bus-x86.so>+0x49db87 gregkh#14 0x000021afcf99091d in publish_acpi_devices(acpi::Manager*, zx_device_t*, zx_device_t*) ../../src/devices/board/drivers/x86/acpi-nswalk.cc:95 <platform-bus-x86.so>+0x25091d gregkh#15 0x000021afcf9c1d4e in x86::X86::do_init(x86::X86*) ../../src/devices/board/drivers/x86/x86.cc:60 <platform-bus-x86.so>+0x281d4e gregkh#16 0x000021afcf9e33ad in λ(x86::X86::ddk_init::(anon class)*) ../../src/devices/board/drivers/x86/x86.cc:77 <platform-bus-x86.so>+0x2a33ad gregkh#17 0x000021afcf9e313e in fit::internal::target<(lambda at../../src/devices/board/drivers/x86/x86.cc:76:19), false, false, std::__2::allocator<std::byte>, void>::invoke(void*) ../../sdk/lib/fit/include/lib/fit/internal/function.h:183 <platform-bus-x86.so>+0x2a313e gregkh#18 0x000021afcfbab4c7 in fit::internal::function_base<16UL, false, void(), std::__2::allocator<std::byte>>::invoke(const fit::internal::function_base<16UL, false, void (), std::__2::allocator<std::byte> >*) ../../sdk/lib/fit/include/lib/fit/internal/function.h:522 <platform-bus-x86.so>+0x46b4c7 gregkh#19 0x000021afcfbab342 in fit::function_impl<16UL, false, void(), std::__2::allocator<std::byte>>::operator()(const fit::function_impl<16UL, false, void (), std::__2::allocator<std::byte> >*) ../../sdk/lib/fit/include/lib/fit/function.h:315 <platform-bus-x86.so>+0x46b342 gregkh#20 0x000021afcfcd98c3 in async::internal::retained_task::Handler(async_dispatcher_t*, async_task_t*, zx_status_t) ../../sdk/lib/async/task.cc:24 <platform-bus-x86.so>+0x5998c3 gregkh#21 0x00002290f9924616 in λ(const driver_runtime::Dispatcher::post_task::(anon class)*, std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request> >, zx_status_t) ../../src/devices/bin/driver_runtime/dispatcher.cc:789 <libdriver_runtime.so>+0x10a616 #22 0x00002290f9924323 in fit::internal::target<(lambda at../../src/devices/bin/driver_runtime/dispatcher.cc:788:7), true, false, std::__2::allocator<std::byte>, void, std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request>>, int>::invoke(void*, std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request> >, int) ../../sdk/lib/fit/include/lib/fit/internal/function.h:128 <libdriver_runtime.so>+0x10a323 #23 0x00002290f9904b76 in fit::internal::function_base<24UL, true, void(std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request>>, int), std::__2::allocator<std::byte>>::invoke(const fit::internal::function_base<24UL, true, void (std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request> >, int), std::__2::allocator<std::byte> >*, std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request> >, int) ../../sdk/lib/fit/include/lib/fit/internal/function.h:522 <libdriver_runtime.so>+0xeab76 #24 0x00002290f9904831 in fit::callback_impl<24UL, true, void(std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request>>, int), std::__2::allocator<std::byte>>::operator()(fit::callback_impl<24UL, true, void (std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request> >, int), std::__2::allocator<std::byte> >*, std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request> >, int) ../../sdk/lib/fit/include/lib/fit/function.h:471 <libdriver_runtime.so>+0xea831 #25 0x00002290f98d5adc in driver_runtime::callback_request::Call(driver_runtime::callback_request*, std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request> >, zx_status_t) ../../src/devices/bin/driver_runtime/callback_request.h:74 <libdriver_runtime.so>+0xbbadc #26 0x00002290f98e1e58 in driver_runtime::Dispatcher::dispatch_callback(driver_runtime::Dispatcher*, std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request> >) ../../src/devices/bin/driver_runtime/dispatcher.cc:1248 <libdriver_runtime.so>+0xc7e58 #27 0x00002290f98e4159 in driver_runtime::Dispatcher::dispatch_callbacks(driver_runtime::Dispatcher*, std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, fbl::ref_ptr<driver_runtime::Dispatcher>) ../../src/devices/bin/driver_runtime/dispatcher.cc:1308 <libdriver_runtime.so>+0xca159 #28 0x00002290f9918414 in λ(const driver_runtime::Dispatcher::create_with_adder::(anon class)*, std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, fbl::ref_ptr<driver_runtime::Dispatcher>) ../../src/devices/bin/driver_runtime/dispatcher.cc:353 <libdriver_runtime.so>+0xfe414 #29 0x00002290f991812d in fit::internal::target<(lambda at../../src/devices/bin/driver_runtime/dispatcher.cc:351:7), true, false, std::__2::allocator<std::byte>, void, std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter>>, fbl::ref_ptr<driver_runtime::Dispatcher>>::invoke(void*, std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, fbl::ref_ptr<driver_runtime::Dispatcher>) ../../sdk/lib/fit/include/lib/fit/internal/function.h:128 <libdriver_runtime.so>+0xfe12d #30 0x00002290f9906fc7 in fit::internal::function_base<8UL, true, void(std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter>>, fbl::ref_ptr<driver_runtime::Dispatcher>), std::__2::allocator<std::byte>>::invoke(const fit::internal::function_base<8UL, true, void (std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, fbl::ref_ptr<driver_runtime::Dispatcher>), std::__2::allocator<std::byte> >*, std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, fbl::ref_ptr<driver_runtime::Dispatcher>) ../../sdk/lib/fit/include/lib/fit/internal/function.h:522 <libdriver_runtime.so>+0xecfc7 #31 0x00002290f9906c66 in fit::function_impl<8UL, true, void(std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter>>, fbl::ref_ptr<driver_runtime::Dispatcher>), std::__2::allocator<std::byte>>::operator()(const fit::function_impl<8UL, true, void (std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, fbl::ref_ptr<driver_runtime::Dispatcher>), std::__2::allocator<std::byte> >*, std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, fbl::ref_ptr<driver_runtime::Dispatcher>) ../../sdk/lib/fit/include/lib/fit/function.h:315 <libdriver_runtime.so>+0xecc66 #32 0x00002290f98e73d9 in driver_runtime::Dispatcher::event_waiter::invoke_callback(driver_runtime::Dispatcher::event_waiter*, std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, fbl::ref_ptr<driver_runtime::Dispatcher>) ../../src/devices/bin/driver_runtime/dispatcher.h:543 <libdriver_runtime.so>+0xcd3d9 #33 0x00002290f98e700d in driver_runtime::Dispatcher::event_waiter::handle_event(std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, async_dispatcher_t*, async::wait_base*, zx_status_t, zx_packet_signal_t const*) ../../src/devices/bin/driver_runtime/dispatcher.cc:1442 <libdriver_runtime.so>+0xcd00d #34 0x00002290f9918983 in async_loop_owned_event_handler<driver_runtime::Dispatcher::event_waiter>::handle_event(async_loop_owned_event_handler<driver_runtime::Dispatcher::event_waiter>*, async_dispatcher_t*, async::wait_base*, zx_status_t, zx_packet_signal_t const*) ../../src/devices/bin/driver_runtime/async_loop_owned_event_handler.h:59 <libdriver_runtime.so>+0xfe983 #35 0x00002290f9918b9e in async::wait_method<async_loop_owned_event_handler<driver_runtime::Dispatcher::event_waiter>, &async_loop_owned_event_handler<driver_runtime::Dispatcher::event_waiter>::handle_event>::call_handler(async_dispatcher_t*, async_wait_t*, zx_status_t, zx_packet_signal_t const*) ../../sdk/lib/async/include/lib/async/cpp/wait.h:201 <libdriver_runtime.so>+0xfeb9e #36 0x00002290f99bf509 in async_loop_dispatch_wait(async_loop_t*, async_wait_t*, zx_status_t, zx_packet_signal_t const*) ../../sdk/lib/async-loop/loop.c:394 <libdriver_runtime.so>+0x1a5509 #37 0x00002290f99b9958 in async_loop_run_once(async_loop_t*, zx_time_t) ../../sdk/lib/async-loop/loop.c:343 <libdriver_runtime.so>+0x19f958 #38 0x00002290f99b9247 in async_loop_run(async_loop_t*, zx_time_t, _Bool) ../../sdk/lib/async-loop/loop.c:301 <libdriver_runtime.so>+0x19f247 #39 0x00002290f99ba962 in async_loop_run_thread(void*) ../../sdk/lib/async-loop/loop.c:860 <libdriver_runtime.so>+0x1a0962 #40 0x000041afd176ef30 in start_c11(void*) ../../zircon/third_party/ulib/musl/pthread/pthread_create.c:63 <libc.so>+0x84f30 #41 0x000041afd18a448d in thread_trampoline(uintptr_t, uintptr_t) ../../zircon/system/ulib/runtime/thread.cc:100 <libc.so>+0x1ba48d Link: acpica/acpica@1c28da22 Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://patch.msgid.link/4664267.LvFx2qVVIh@rjwysocki.net Signed-off-by: Tamir Duberstein <tamird@gmail.com> [ rjw: Pick up the tag from Tamir ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit ee684de ] As shown in [1], it is possible to corrupt a BPF ELF file such that arbitrary BPF instructions are loaded by libbpf. This can be done by setting a symbol (BPF program) section offset to a large (unsigned) number such that <section start + symbol offset> overflows and points before the section data in the memory. Consider the situation below where: - prog_start = sec_start + symbol_offset <-- size_t overflow here - prog_end = prog_start + prog_size prog_start sec_start prog_end sec_end | | | | v v v v .....................|################################|............ The report in [1] also provides a corrupted BPF ELF which can be used as a reproducer: $ readelf -S crash Section Headers: [Nr] Name Type Address Offset Size EntSize Flags Link Info Align ... [ 2] uretprobe.mu[...] PROGBITS 0000000000000000 00000040 0000000000000068 0000000000000000 AX 0 0 8 $ readelf -s crash Symbol table '.symtab' contains 8 entries: Num: Value Size Type Bind Vis Ndx Name ... 6: ffffffffffffffb8 104 FUNC GLOBAL DEFAULT 2 handle_tp Here, the handle_tp prog has section offset ffffffffffffffb8, i.e. will point before the actual memory where section 2 is allocated. This is also reported by AddressSanitizer: ================================================================= ==1232==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x7c7302fe0000 at pc 0x7fc3046e4b77 bp 0x7ffe64677cd0 sp 0x7ffe64677490 READ of size 104 at 0x7c7302fe0000 thread T0 #0 0x7fc3046e4b76 in memcpy (/lib64/libasan.so.8+0xe4b76) #1 0x00000040df3e in bpf_object__init_prog /src/libbpf/src/libbpf.c:856 #2 0x00000040df3e in bpf_object__add_programs /src/libbpf/src/libbpf.c:928 #3 0x00000040df3e in bpf_object__elf_collect /src/libbpf/src/libbpf.c:3930 #4 0x00000040df3e in bpf_object_open /src/libbpf/src/libbpf.c:8067 #5 0x00000040f176 in bpf_object__open_file /src/libbpf/src/libbpf.c:8090 gregkh#6 0x000000400c16 in main /poc/poc.c:8 gregkh#7 0x7fc3043d25b4 in __libc_start_call_main (/lib64/libc.so.6+0x35b4) gregkh#8 0x7fc3043d2667 in __libc_start_main@@GLIBC_2.34 (/lib64/libc.so.6+0x3667) gregkh#9 0x000000400b34 in _start (/poc/poc+0x400b34) 0x7c7302fe0000 is located 64 bytes before 104-byte region [0x7c7302fe0040,0x7c7302fe00a8) allocated by thread T0 here: #0 0x7fc3046e716b in malloc (/lib64/libasan.so.8+0xe716b) #1 0x7fc3045ee600 in __libelf_set_rawdata_wrlock (/lib64/libelf.so.1+0xb600) #2 0x7fc3045ef018 in __elf_getdata_rdlock (/lib64/libelf.so.1+0xc018) #3 0x00000040642f in elf_sec_data /src/libbpf/src/libbpf.c:3740 The problem here is that currently, libbpf only checks that the program end is within the section bounds. There used to be a check `while (sec_off < sec_sz)` in bpf_object__add_programs, however, it was removed by commit 6245947 ("libbpf: Allow gaps in BPF program sections to support overriden weak functions"). Add a check for detecting the overflow of `sec_off + prog_sz` to bpf_object__init_prog to fix this issue. [1] https://github.com/lmarch2/poc/blob/main/libbpf/libbpf.md Fixes: 6245947 ("libbpf: Allow gaps in BPF program sections to support overriden weak functions") Reported-by: lmarch2 <2524158037@qq.com> Signed-off-by: Viktor Malik <vmalik@redhat.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Shung-Hsi Yu <shung-hsi.yu@suse.com> Link: https://github.com/lmarch2/poc/blob/main/libbpf/libbpf.md Link: https://lore.kernel.org/bpf/20250415155014.397603-1-vmalik@redhat.com Signed-off-by: Sasha Levin <sashal@kernel.org>
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Jun 27, 2025
[ Upstream commit eedf3e3 ] ACPICA commit 1c28da2242783579d59767617121035dafba18c3 This was originally done in NetBSD: NetBSD/src@b69d1ac and is the correct alternative to the smattering of `memcpy`s I previously contributed to this repository. This also sidesteps the newly strict checks added in UBSAN: llvm/llvm-project@7926744 Before this change we see the following UBSAN stack trace in Fuchsia: #0 0x000021afcfdeca5e in acpi_rs_get_address_common(struct acpi_resource*, union aml_resource*) ../../third_party/acpica/source/components/resources/rsaddr.c:329 <platform-bus-x86.so>+0x6aca5e #1.2 0x000021982bc4af3c in ubsan_get_stack_trace() compiler-rt/lib/ubsan/ubsan_diag.cpp:41 <libclang_rt.asan.so>+0x41f3c #1.1 0x000021982bc4af3c in maybe_print_stack_trace() compiler-rt/lib/ubsan/ubsan_diag.cpp:51 <libclang_rt.asan.so>+0x41f3c #1 0x000021982bc4af3c in ~scoped_report() compiler-rt/lib/ubsan/ubsan_diag.cpp:395 <libclang_rt.asan.so>+0x41f3c #2 0x000021982bc4bb6f in handletype_mismatch_impl() compiler-rt/lib/ubsan/ubsan_handlers.cpp:137 <libclang_rt.asan.so>+0x42b6f #3 0x000021982bc4b723 in __ubsan_handle_type_mismatch_v1 compiler-rt/lib/ubsan/ubsan_handlers.cpp:142 <libclang_rt.asan.so>+0x42723 #4 0x000021afcfdeca5e in acpi_rs_get_address_common(struct acpi_resource*, union aml_resource*) ../../third_party/acpica/source/components/resources/rsaddr.c:329 <platform-bus-x86.so>+0x6aca5e #5 0x000021afcfdf2089 in acpi_rs_convert_aml_to_resource(struct acpi_resource*, union aml_resource*, struct acpi_rsconvert_info*) ../../third_party/acpica/source/components/resources/rsmisc.c:355 <platform-bus-x86.so>+0x6b2089 gregkh#6 0x000021afcfded169 in acpi_rs_convert_aml_to_resources(u8*, u32, u32, u8, void**) ../../third_party/acpica/source/components/resources/rslist.c:137 <platform-bus-x86.so>+0x6ad169 gregkh#7 0x000021afcfe2d24a in acpi_ut_walk_aml_resources(struct acpi_walk_state*, u8*, acpi_size, acpi_walk_aml_callback, void**) ../../third_party/acpica/source/components/utilities/utresrc.c:237 <platform-bus-x86.so>+0x6ed24a gregkh#8 0x000021afcfde66b7 in acpi_rs_create_resource_list(union acpi_operand_object*, struct acpi_buffer*) ../../third_party/acpica/source/components/resources/rscreate.c:199 <platform-bus-x86.so>+0x6a66b7 gregkh#9 0x000021afcfdf6979 in acpi_rs_get_method_data(acpi_handle, const char*, struct acpi_buffer*) ../../third_party/acpica/source/components/resources/rsutils.c:770 <platform-bus-x86.so>+0x6b6979 gregkh#10 0x000021afcfdf708f in acpi_walk_resources(acpi_handle, char*, acpi_walk_resource_callback, void*) ../../third_party/acpica/source/components/resources/rsxface.c:731 <platform-bus-x86.so>+0x6b708f gregkh#11 0x000021afcfa95dcf in acpi::acpi_impl::walk_resources(acpi::acpi_impl*, acpi_handle, const char*, acpi::Acpi::resources_callable) ../../src/devices/board/lib/acpi/acpi-impl.cc:41 <platform-bus-x86.so>+0x355dcf gregkh#12 0x000021afcfaa8278 in acpi::device_builder::gather_resources(acpi::device_builder*, acpi::Acpi*, fidl::any_arena&, acpi::Manager*, acpi::device_builder::gather_resources_callback) ../../src/devices/board/lib/acpi/device-builder.cc:84 <platform-bus-x86.so>+0x368278 gregkh#13 0x000021afcfbddb87 in acpi::Manager::configure_discovered_devices(acpi::Manager*) ../../src/devices/board/lib/acpi/manager.cc:75 <platform-bus-x86.so>+0x49db87 gregkh#14 0x000021afcf99091d in publish_acpi_devices(acpi::Manager*, zx_device_t*, zx_device_t*) ../../src/devices/board/drivers/x86/acpi-nswalk.cc:95 <platform-bus-x86.so>+0x25091d gregkh#15 0x000021afcf9c1d4e in x86::X86::do_init(x86::X86*) ../../src/devices/board/drivers/x86/x86.cc:60 <platform-bus-x86.so>+0x281d4e gregkh#16 0x000021afcf9e33ad in λ(x86::X86::ddk_init::(anon class)*) ../../src/devices/board/drivers/x86/x86.cc:77 <platform-bus-x86.so>+0x2a33ad gregkh#17 0x000021afcf9e313e in fit::internal::target<(lambda at../../src/devices/board/drivers/x86/x86.cc:76:19), false, false, std::__2::allocator<std::byte>, void>::invoke(void*) ../../sdk/lib/fit/include/lib/fit/internal/function.h:183 <platform-bus-x86.so>+0x2a313e gregkh#18 0x000021afcfbab4c7 in fit::internal::function_base<16UL, false, void(), std::__2::allocator<std::byte>>::invoke(const fit::internal::function_base<16UL, false, void (), std::__2::allocator<std::byte> >*) ../../sdk/lib/fit/include/lib/fit/internal/function.h:522 <platform-bus-x86.so>+0x46b4c7 gregkh#19 0x000021afcfbab342 in fit::function_impl<16UL, false, void(), std::__2::allocator<std::byte>>::operator()(const fit::function_impl<16UL, false, void (), std::__2::allocator<std::byte> >*) ../../sdk/lib/fit/include/lib/fit/function.h:315 <platform-bus-x86.so>+0x46b342 gregkh#20 0x000021afcfcd98c3 in async::internal::retained_task::Handler(async_dispatcher_t*, async_task_t*, zx_status_t) ../../sdk/lib/async/task.cc:24 <platform-bus-x86.so>+0x5998c3 gregkh#21 0x00002290f9924616 in λ(const driver_runtime::Dispatcher::post_task::(anon class)*, std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request> >, zx_status_t) ../../src/devices/bin/driver_runtime/dispatcher.cc:789 <libdriver_runtime.so>+0x10a616 #22 0x00002290f9924323 in fit::internal::target<(lambda at../../src/devices/bin/driver_runtime/dispatcher.cc:788:7), true, false, std::__2::allocator<std::byte>, void, std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request>>, int>::invoke(void*, std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request> >, int) ../../sdk/lib/fit/include/lib/fit/internal/function.h:128 <libdriver_runtime.so>+0x10a323 #23 0x00002290f9904b76 in fit::internal::function_base<24UL, true, void(std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request>>, int), std::__2::allocator<std::byte>>::invoke(const fit::internal::function_base<24UL, true, void (std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request> >, int), std::__2::allocator<std::byte> >*, std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request> >, int) ../../sdk/lib/fit/include/lib/fit/internal/function.h:522 <libdriver_runtime.so>+0xeab76 #24 0x00002290f9904831 in fit::callback_impl<24UL, true, void(std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request>>, int), std::__2::allocator<std::byte>>::operator()(fit::callback_impl<24UL, true, void (std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request> >, int), std::__2::allocator<std::byte> >*, std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request> >, int) ../../sdk/lib/fit/include/lib/fit/function.h:471 <libdriver_runtime.so>+0xea831 #25 0x00002290f98d5adc in driver_runtime::callback_request::Call(driver_runtime::callback_request*, std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request> >, zx_status_t) ../../src/devices/bin/driver_runtime/callback_request.h:74 <libdriver_runtime.so>+0xbbadc #26 0x00002290f98e1e58 in driver_runtime::Dispatcher::dispatch_callback(driver_runtime::Dispatcher*, std::__2::unique_ptr<driver_runtime::callback_request, std::__2::default_delete<driver_runtime::callback_request> >) ../../src/devices/bin/driver_runtime/dispatcher.cc:1248 <libdriver_runtime.so>+0xc7e58 #27 0x00002290f98e4159 in driver_runtime::Dispatcher::dispatch_callbacks(driver_runtime::Dispatcher*, std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, fbl::ref_ptr<driver_runtime::Dispatcher>) ../../src/devices/bin/driver_runtime/dispatcher.cc:1308 <libdriver_runtime.so>+0xca159 #28 0x00002290f9918414 in λ(const driver_runtime::Dispatcher::create_with_adder::(anon class)*, std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, fbl::ref_ptr<driver_runtime::Dispatcher>) ../../src/devices/bin/driver_runtime/dispatcher.cc:353 <libdriver_runtime.so>+0xfe414 #29 0x00002290f991812d in fit::internal::target<(lambda at../../src/devices/bin/driver_runtime/dispatcher.cc:351:7), true, false, std::__2::allocator<std::byte>, void, std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter>>, fbl::ref_ptr<driver_runtime::Dispatcher>>::invoke(void*, std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, fbl::ref_ptr<driver_runtime::Dispatcher>) ../../sdk/lib/fit/include/lib/fit/internal/function.h:128 <libdriver_runtime.so>+0xfe12d #30 0x00002290f9906fc7 in fit::internal::function_base<8UL, true, void(std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter>>, fbl::ref_ptr<driver_runtime::Dispatcher>), std::__2::allocator<std::byte>>::invoke(const fit::internal::function_base<8UL, true, void (std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, fbl::ref_ptr<driver_runtime::Dispatcher>), std::__2::allocator<std::byte> >*, std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, fbl::ref_ptr<driver_runtime::Dispatcher>) ../../sdk/lib/fit/include/lib/fit/internal/function.h:522 <libdriver_runtime.so>+0xecfc7 #31 0x00002290f9906c66 in fit::function_impl<8UL, true, void(std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter>>, fbl::ref_ptr<driver_runtime::Dispatcher>), std::__2::allocator<std::byte>>::operator()(const fit::function_impl<8UL, true, void (std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, fbl::ref_ptr<driver_runtime::Dispatcher>), std::__2::allocator<std::byte> >*, std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, fbl::ref_ptr<driver_runtime::Dispatcher>) ../../sdk/lib/fit/include/lib/fit/function.h:315 <libdriver_runtime.so>+0xecc66 #32 0x00002290f98e73d9 in driver_runtime::Dispatcher::event_waiter::invoke_callback(driver_runtime::Dispatcher::event_waiter*, std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, fbl::ref_ptr<driver_runtime::Dispatcher>) ../../src/devices/bin/driver_runtime/dispatcher.h:543 <libdriver_runtime.so>+0xcd3d9 #33 0x00002290f98e700d in driver_runtime::Dispatcher::event_waiter::handle_event(std::__2::unique_ptr<driver_runtime::Dispatcher::event_waiter, std::__2::default_delete<driver_runtime::Dispatcher::event_waiter> >, async_dispatcher_t*, async::wait_base*, zx_status_t, zx_packet_signal_t const*) ../../src/devices/bin/driver_runtime/dispatcher.cc:1442 <libdriver_runtime.so>+0xcd00d #34 0x00002290f9918983 in async_loop_owned_event_handler<driver_runtime::Dispatcher::event_waiter>::handle_event(async_loop_owned_event_handler<driver_runtime::Dispatcher::event_waiter>*, async_dispatcher_t*, async::wait_base*, zx_status_t, zx_packet_signal_t const*) ../../src/devices/bin/driver_runtime/async_loop_owned_event_handler.h:59 <libdriver_runtime.so>+0xfe983 #35 0x00002290f9918b9e in async::wait_method<async_loop_owned_event_handler<driver_runtime::Dispatcher::event_waiter>, &async_loop_owned_event_handler<driver_runtime::Dispatcher::event_waiter>::handle_event>::call_handler(async_dispatcher_t*, async_wait_t*, zx_status_t, zx_packet_signal_t const*) ../../sdk/lib/async/include/lib/async/cpp/wait.h:201 <libdriver_runtime.so>+0xfeb9e #36 0x00002290f99bf509 in async_loop_dispatch_wait(async_loop_t*, async_wait_t*, zx_status_t, zx_packet_signal_t const*) ../../sdk/lib/async-loop/loop.c:394 <libdriver_runtime.so>+0x1a5509 #37 0x00002290f99b9958 in async_loop_run_once(async_loop_t*, zx_time_t) ../../sdk/lib/async-loop/loop.c:343 <libdriver_runtime.so>+0x19f958 #38 0x00002290f99b9247 in async_loop_run(async_loop_t*, zx_time_t, _Bool) ../../sdk/lib/async-loop/loop.c:301 <libdriver_runtime.so>+0x19f247 #39 0x00002290f99ba962 in async_loop_run_thread(void*) ../../sdk/lib/async-loop/loop.c:860 <libdriver_runtime.so>+0x1a0962 #40 0x000041afd176ef30 in start_c11(void*) ../../zircon/third_party/ulib/musl/pthread/pthread_create.c:63 <libc.so>+0x84f30 #41 0x000041afd18a448d in thread_trampoline(uintptr_t, uintptr_t) ../../zircon/system/ulib/runtime/thread.cc:100 <libc.so>+0x1ba48d Link: acpica/acpica@1c28da22 Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://patch.msgid.link/4664267.LvFx2qVVIh@rjwysocki.net Signed-off-by: Tamir Duberstein <tamird@gmail.com> [ rjw: Pick up the tag from Tamir ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
paniakin-aws
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Jun 27, 2025
[ Upstream commit ee684de ] As shown in [1], it is possible to corrupt a BPF ELF file such that arbitrary BPF instructions are loaded by libbpf. This can be done by setting a symbol (BPF program) section offset to a large (unsigned) number such that <section start + symbol offset> overflows and points before the section data in the memory. Consider the situation below where: - prog_start = sec_start + symbol_offset <-- size_t overflow here - prog_end = prog_start + prog_size prog_start sec_start prog_end sec_end | | | | v v v v .....................|################################|............ The report in [1] also provides a corrupted BPF ELF which can be used as a reproducer: $ readelf -S crash Section Headers: [Nr] Name Type Address Offset Size EntSize Flags Link Info Align ... [ 2] uretprobe.mu[...] PROGBITS 0000000000000000 00000040 0000000000000068 0000000000000000 AX 0 0 8 $ readelf -s crash Symbol table '.symtab' contains 8 entries: Num: Value Size Type Bind Vis Ndx Name ... 6: ffffffffffffffb8 104 FUNC GLOBAL DEFAULT 2 handle_tp Here, the handle_tp prog has section offset ffffffffffffffb8, i.e. will point before the actual memory where section 2 is allocated. This is also reported by AddressSanitizer: ================================================================= ==1232==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x7c7302fe0000 at pc 0x7fc3046e4b77 bp 0x7ffe64677cd0 sp 0x7ffe64677490 READ of size 104 at 0x7c7302fe0000 thread T0 #0 0x7fc3046e4b76 in memcpy (/lib64/libasan.so.8+0xe4b76) #1 0x00000040df3e in bpf_object__init_prog /src/libbpf/src/libbpf.c:856 #2 0x00000040df3e in bpf_object__add_programs /src/libbpf/src/libbpf.c:928 #3 0x00000040df3e in bpf_object__elf_collect /src/libbpf/src/libbpf.c:3930 #4 0x00000040df3e in bpf_object_open /src/libbpf/src/libbpf.c:8067 #5 0x00000040f176 in bpf_object__open_file /src/libbpf/src/libbpf.c:8090 gregkh#6 0x000000400c16 in main /poc/poc.c:8 gregkh#7 0x7fc3043d25b4 in __libc_start_call_main (/lib64/libc.so.6+0x35b4) gregkh#8 0x7fc3043d2667 in __libc_start_main@@GLIBC_2.34 (/lib64/libc.so.6+0x3667) gregkh#9 0x000000400b34 in _start (/poc/poc+0x400b34) 0x7c7302fe0000 is located 64 bytes before 104-byte region [0x7c7302fe0040,0x7c7302fe00a8) allocated by thread T0 here: #0 0x7fc3046e716b in malloc (/lib64/libasan.so.8+0xe716b) #1 0x7fc3045ee600 in __libelf_set_rawdata_wrlock (/lib64/libelf.so.1+0xb600) #2 0x7fc3045ef018 in __elf_getdata_rdlock (/lib64/libelf.so.1+0xc018) #3 0x00000040642f in elf_sec_data /src/libbpf/src/libbpf.c:3740 The problem here is that currently, libbpf only checks that the program end is within the section bounds. There used to be a check `while (sec_off < sec_sz)` in bpf_object__add_programs, however, it was removed by commit 6245947 ("libbpf: Allow gaps in BPF program sections to support overriden weak functions"). Add a check for detecting the overflow of `sec_off + prog_sz` to bpf_object__init_prog to fix this issue. [1] https://github.com/lmarch2/poc/blob/main/libbpf/libbpf.md Fixes: 6245947 ("libbpf: Allow gaps in BPF program sections to support overriden weak functions") Reported-by: lmarch2 <2524158037@qq.com> Signed-off-by: Viktor Malik <vmalik@redhat.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Shung-Hsi Yu <shung-hsi.yu@suse.com> Link: https://github.com/lmarch2/poc/blob/main/libbpf/libbpf.md Link: https://lore.kernel.org/bpf/20250415155014.397603-1-vmalik@redhat.com Signed-off-by: Sasha Levin <sashal@kernel.org>
nathan-zcgao
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Jun 27, 2025
…ress Bug report and analysis from Ding Hui. During iSCSI session logout, if another task accesses the shost ipaddress attr, we can get a KASAN UAF report like this: [ 276.942144] BUG: KASAN: use-after-free in _raw_spin_lock_bh+0x78/0xe0 [ 276.942535] Write of size 4 at addr ffff8881053b45b8 by task cat/4088 [ 276.943511] CPU: 2 PID: 4088 Comm: cat Tainted: G E 6.1.0-rc8+ #3 [ 276.943997] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020 [ 276.944470] Call Trace: [ 276.944943] <TASK> [ 276.945397] dump_stack_lvl+0x34/0x48 [ 276.945887] print_address_description.constprop.0+0x86/0x1e7 [ 276.946421] print_report+0x36/0x4f [ 276.947358] kasan_report+0xad/0x130 [ 276.948234] kasan_check_range+0x35/0x1c0 [ 276.948674] _raw_spin_lock_bh+0x78/0xe0 [ 276.949989] iscsi_sw_tcp_host_get_param+0xad/0x2e0 [iscsi_tcp] [ 276.951765] show_host_param_ISCSI_HOST_PARAM_IPADDRESS+0xe9/0x130 [scsi_transport_iscsi] [ 276.952185] dev_attr_show+0x3f/0x80 [ 276.953005] sysfs_kf_seq_show+0x1fb/0x3e0 [ 276.953401] seq_read_iter+0x402/0x1020 [ 276.954260] vfs_read+0x532/0x7b0 [ 276.955113] ksys_read+0xed/0x1c0 [ 276.955952] do_syscall_64+0x38/0x90 [ 276.956347] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 276.956769] RIP: 0033:0x7f5d3a679222 [ 276.957161] Code: c0 e9 b2 fe ff ff 50 48 8d 3d 32 c0 0b 00 e8 a5 fe 01 00 0f 1f 44 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 0f 05 <48> 3d 00 f0 ff ff 77 56 c3 0f 1f 44 00 00 48 83 ec 28 48 89 54 24 [ 276.958009] RSP: 002b:00007ffc864d16a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 276.958431] RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f5d3a679222 [ 276.958857] RDX: 0000000000020000 RSI: 00007f5d3a4fe000 RDI: 0000000000000003 [ 276.959281] RBP: 00007f5d3a4fe000 R08: 00000000ffffffff R09: 0000000000000000 [ 276.959682] R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000020000 [ 276.960126] R13: 0000000000000003 R14: 0000000000000000 R15: 0000557a26dada58 [ 276.960536] </TASK> [ 276.961357] Allocated by task 2209: [ 276.961756] kasan_save_stack+0x1e/0x40 [ 276.962170] kasan_set_track+0x21/0x30 [ 276.962557] __kasan_kmalloc+0x7e/0x90 [ 276.962923] __kmalloc+0x5b/0x140 [ 276.963308] iscsi_alloc_session+0x28/0x840 [scsi_transport_iscsi] [ 276.963712] iscsi_session_setup+0xda/0xba0 [libiscsi] [ 276.964078] iscsi_sw_tcp_session_create+0x1fd/0x330 [iscsi_tcp] [ 276.964431] iscsi_if_create_session.isra.0+0x50/0x260 [scsi_transport_iscsi] [ 276.964793] iscsi_if_recv_msg+0xc5a/0x2660 [scsi_transport_iscsi] [ 276.965153] iscsi_if_rx+0x198/0x4b0 [scsi_transport_iscsi] [ 276.965546] netlink_unicast+0x4d5/0x7b0 [ 276.965905] netlink_sendmsg+0x78d/0xc30 [ 276.966236] sock_sendmsg+0xe5/0x120 [ 276.966576] ____sys_sendmsg+0x5fe/0x860 [ 276.966923] ___sys_sendmsg+0xe0/0x170 [ 276.967300] __sys_sendmsg+0xc8/0x170 [ 276.967666] do_syscall_64+0x38/0x90 [ 276.968028] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 276.968773] Freed by task 2209: [ 276.969111] kasan_save_stack+0x1e/0x40 [ 276.969449] kasan_set_track+0x21/0x30 [ 276.969789] kasan_save_free_info+0x2a/0x50 [ 276.970146] __kasan_slab_free+0x106/0x190 [ 276.970470] __kmem_cache_free+0x133/0x270 [ 276.970816] device_release+0x98/0x210 [ 276.971145] kobject_cleanup+0x101/0x360 [ 276.971462] iscsi_session_teardown+0x3fb/0x530 [libiscsi] [ 276.971775] iscsi_sw_tcp_session_destroy+0xd8/0x130 [iscsi_tcp] [ 276.972143] iscsi_if_recv_msg+0x1bf1/0x2660 [scsi_transport_iscsi] [ 276.972485] iscsi_if_rx+0x198/0x4b0 [scsi_transport_iscsi] [ 276.972808] netlink_unicast+0x4d5/0x7b0 [ 276.973201] netlink_sendmsg+0x78d/0xc30 [ 276.973544] sock_sendmsg+0xe5/0x120 [ 276.973864] ____sys_sendmsg+0x5fe/0x860 [ 276.974248] ___sys_sendmsg+0xe0/0x170 [ 276.974583] __sys_sendmsg+0xc8/0x170 [ 276.974891] do_syscall_64+0x38/0x90 [ 276.975216] entry_SYSCALL_64_after_hwframe+0x63/0xcd We can easily reproduce by two tasks: 1. while :; do iscsiadm -m node --login; iscsiadm -m node --logout; done 2. while :; do cat \ /sys/devices/platform/host*/iscsi_host/host*/ipaddress; done iscsid | cat --------------------------------+--------------------------------------- |- iscsi_sw_tcp_session_destroy | |- iscsi_session_teardown | |- device_release | |- iscsi_session_release ||- dev_attr_show |- kfree | |- show_host_param_ | ISCSI_HOST_PARAM_IPADDRESS | |- iscsi_sw_tcp_host_get_param | |- r/w tcp_sw_host->session (UAF) |- iscsi_host_remove | |- iscsi_host_free | Fix the above bug by splitting the session removal into 2 parts: 1. removal from iSCSI class which includes sysfs and removal from host tracking. 2. freeing of session. During iscsi_tcp host and session removal we can remove the session from sysfs then remove the host from sysfs. At this point we know userspace is not accessing the kernel via sysfs so we can free the session and host. Link: https://lore.kernel.org/r/20230117193937.21244-2-michael.christie@oracle.com Signed-off-by: Mike Christie <michael.christie@oracle.com> Reviewed-by: Lee Duncan <lduncan@suse.com> Acked-by: Ding Hui <dinghui@sangfor.com.cn> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> (cherry picked from commit 6f1d64b) [fixed to apply on 4.14] Signed-off-by: Puranjay Mohan <pjy@amazon.com>
nathan-zcgao
pushed a commit
that referenced
this pull request
Jun 27, 2025
…ress Bug report and analysis from Ding Hui. During iSCSI session logout, if another task accesses the shost ipaddress attr, we can get a KASAN UAF report like this: [ 276.942144] BUG: KASAN: use-after-free in _raw_spin_lock_bh+0x78/0xe0 [ 276.942535] Write of size 4 at addr ffff8881053b45b8 by task cat/4088 [ 276.943511] CPU: 2 PID: 4088 Comm: cat Tainted: G E 6.1.0-rc8+ #3 [ 276.943997] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020 [ 276.944470] Call Trace: [ 276.944943] <TASK> [ 276.945397] dump_stack_lvl+0x34/0x48 [ 276.945887] print_address_description.constprop.0+0x86/0x1e7 [ 276.946421] print_report+0x36/0x4f [ 276.947358] kasan_report+0xad/0x130 [ 276.948234] kasan_check_range+0x35/0x1c0 [ 276.948674] _raw_spin_lock_bh+0x78/0xe0 [ 276.949989] iscsi_sw_tcp_host_get_param+0xad/0x2e0 [iscsi_tcp] [ 276.951765] show_host_param_ISCSI_HOST_PARAM_IPADDRESS+0xe9/0x130 [scsi_transport_iscsi] [ 276.952185] dev_attr_show+0x3f/0x80 [ 276.953005] sysfs_kf_seq_show+0x1fb/0x3e0 [ 276.953401] seq_read_iter+0x402/0x1020 [ 276.954260] vfs_read+0x532/0x7b0 [ 276.955113] ksys_read+0xed/0x1c0 [ 276.955952] do_syscall_64+0x38/0x90 [ 276.956347] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 276.956769] RIP: 0033:0x7f5d3a679222 [ 276.957161] Code: c0 e9 b2 fe ff ff 50 48 8d 3d 32 c0 0b 00 e8 a5 fe 01 00 0f 1f 44 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 0f 05 <48> 3d 00 f0 ff ff 77 56 c3 0f 1f 44 00 00 48 83 ec 28 48 89 54 24 [ 276.958009] RSP: 002b:00007ffc864d16a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 276.958431] RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f5d3a679222 [ 276.958857] RDX: 0000000000020000 RSI: 00007f5d3a4fe000 RDI: 0000000000000003 [ 276.959281] RBP: 00007f5d3a4fe000 R08: 00000000ffffffff R09: 0000000000000000 [ 276.959682] R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000020000 [ 276.960126] R13: 0000000000000003 R14: 0000000000000000 R15: 0000557a26dada58 [ 276.960536] </TASK> [ 276.961357] Allocated by task 2209: [ 276.961756] kasan_save_stack+0x1e/0x40 [ 276.962170] kasan_set_track+0x21/0x30 [ 276.962557] __kasan_kmalloc+0x7e/0x90 [ 276.962923] __kmalloc+0x5b/0x140 [ 276.963308] iscsi_alloc_session+0x28/0x840 [scsi_transport_iscsi] [ 276.963712] iscsi_session_setup+0xda/0xba0 [libiscsi] [ 276.964078] iscsi_sw_tcp_session_create+0x1fd/0x330 [iscsi_tcp] [ 276.964431] iscsi_if_create_session.isra.0+0x50/0x260 [scsi_transport_iscsi] [ 276.964793] iscsi_if_recv_msg+0xc5a/0x2660 [scsi_transport_iscsi] [ 276.965153] iscsi_if_rx+0x198/0x4b0 [scsi_transport_iscsi] [ 276.965546] netlink_unicast+0x4d5/0x7b0 [ 276.965905] netlink_sendmsg+0x78d/0xc30 [ 276.966236] sock_sendmsg+0xe5/0x120 [ 276.966576] ____sys_sendmsg+0x5fe/0x860 [ 276.966923] ___sys_sendmsg+0xe0/0x170 [ 276.967300] __sys_sendmsg+0xc8/0x170 [ 276.967666] do_syscall_64+0x38/0x90 [ 276.968028] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 276.968773] Freed by task 2209: [ 276.969111] kasan_save_stack+0x1e/0x40 [ 276.969449] kasan_set_track+0x21/0x30 [ 276.969789] kasan_save_free_info+0x2a/0x50 [ 276.970146] __kasan_slab_free+0x106/0x190 [ 276.970470] __kmem_cache_free+0x133/0x270 [ 276.970816] device_release+0x98/0x210 [ 276.971145] kobject_cleanup+0x101/0x360 [ 276.971462] iscsi_session_teardown+0x3fb/0x530 [libiscsi] [ 276.971775] iscsi_sw_tcp_session_destroy+0xd8/0x130 [iscsi_tcp] [ 276.972143] iscsi_if_recv_msg+0x1bf1/0x2660 [scsi_transport_iscsi] [ 276.972485] iscsi_if_rx+0x198/0x4b0 [scsi_transport_iscsi] [ 276.972808] netlink_unicast+0x4d5/0x7b0 [ 276.973201] netlink_sendmsg+0x78d/0xc30 [ 276.973544] sock_sendmsg+0xe5/0x120 [ 276.973864] ____sys_sendmsg+0x5fe/0x860 [ 276.974248] ___sys_sendmsg+0xe0/0x170 [ 276.974583] __sys_sendmsg+0xc8/0x170 [ 276.974891] do_syscall_64+0x38/0x90 [ 276.975216] entry_SYSCALL_64_after_hwframe+0x63/0xcd We can easily reproduce by two tasks: 1. while :; do iscsiadm -m node --login; iscsiadm -m node --logout; done 2. while :; do cat \ /sys/devices/platform/host*/iscsi_host/host*/ipaddress; done iscsid | cat --------------------------------+--------------------------------------- |- iscsi_sw_tcp_session_destroy | |- iscsi_session_teardown | |- device_release | |- iscsi_session_release ||- dev_attr_show |- kfree | |- show_host_param_ | ISCSI_HOST_PARAM_IPADDRESS | |- iscsi_sw_tcp_host_get_param | |- r/w tcp_sw_host->session (UAF) |- iscsi_host_remove | |- iscsi_host_free | Fix the above bug by splitting the session removal into 2 parts: 1. removal from iSCSI class which includes sysfs and removal from host tracking. 2. freeing of session. During iscsi_tcp host and session removal we can remove the session from sysfs then remove the host from sysfs. At this point we know userspace is not accessing the kernel via sysfs so we can free the session and host. Link: https://lore.kernel.org/r/20230117193937.21244-2-michael.christie@oracle.com Signed-off-by: Mike Christie <michael.christie@oracle.com> Reviewed-by: Lee Duncan <lduncan@suse.com> Acked-by: Ding Hui <dinghui@sangfor.com.cn> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> (cherry picked from commit 6f1d64b) [Fixed to apply on 5.4] Signed-off-by: Puranjay Mohan <pjy@amazon.com>
nathan-zcgao
pushed a commit
that referenced
this pull request
Jun 27, 2025
…ress Bug report and analysis from Ding Hui. During iSCSI session logout, if another task accesses the shost ipaddress attr, we can get a KASAN UAF report like this: [ 276.942144] BUG: KASAN: use-after-free in _raw_spin_lock_bh+0x78/0xe0 [ 276.942535] Write of size 4 at addr ffff8881053b45b8 by task cat/4088 [ 276.943511] CPU: 2 PID: 4088 Comm: cat Tainted: G E 6.1.0-rc8+ #3 [ 276.943997] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020 [ 276.944470] Call Trace: [ 276.944943] <TASK> [ 276.945397] dump_stack_lvl+0x34/0x48 [ 276.945887] print_address_description.constprop.0+0x86/0x1e7 [ 276.946421] print_report+0x36/0x4f [ 276.947358] kasan_report+0xad/0x130 [ 276.948234] kasan_check_range+0x35/0x1c0 [ 276.948674] _raw_spin_lock_bh+0x78/0xe0 [ 276.949989] iscsi_sw_tcp_host_get_param+0xad/0x2e0 [iscsi_tcp] [ 276.951765] show_host_param_ISCSI_HOST_PARAM_IPADDRESS+0xe9/0x130 [scsi_transport_iscsi] [ 276.952185] dev_attr_show+0x3f/0x80 [ 276.953005] sysfs_kf_seq_show+0x1fb/0x3e0 [ 276.953401] seq_read_iter+0x402/0x1020 [ 276.954260] vfs_read+0x532/0x7b0 [ 276.955113] ksys_read+0xed/0x1c0 [ 276.955952] do_syscall_64+0x38/0x90 [ 276.956347] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 276.956769] RIP: 0033:0x7f5d3a679222 [ 276.957161] Code: c0 e9 b2 fe ff ff 50 48 8d 3d 32 c0 0b 00 e8 a5 fe 01 00 0f 1f 44 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 0f 05 <48> 3d 00 f0 ff ff 77 56 c3 0f 1f 44 00 00 48 83 ec 28 48 89 54 24 [ 276.958009] RSP: 002b:00007ffc864d16a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 276.958431] RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f5d3a679222 [ 276.958857] RDX: 0000000000020000 RSI: 00007f5d3a4fe000 RDI: 0000000000000003 [ 276.959281] RBP: 00007f5d3a4fe000 R08: 00000000ffffffff R09: 0000000000000000 [ 276.959682] R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000020000 [ 276.960126] R13: 0000000000000003 R14: 0000000000000000 R15: 0000557a26dada58 [ 276.960536] </TASK> [ 276.961357] Allocated by task 2209: [ 276.961756] kasan_save_stack+0x1e/0x40 [ 276.962170] kasan_set_track+0x21/0x30 [ 276.962557] __kasan_kmalloc+0x7e/0x90 [ 276.962923] __kmalloc+0x5b/0x140 [ 276.963308] iscsi_alloc_session+0x28/0x840 [scsi_transport_iscsi] [ 276.963712] iscsi_session_setup+0xda/0xba0 [libiscsi] [ 276.964078] iscsi_sw_tcp_session_create+0x1fd/0x330 [iscsi_tcp] [ 276.964431] iscsi_if_create_session.isra.0+0x50/0x260 [scsi_transport_iscsi] [ 276.964793] iscsi_if_recv_msg+0xc5a/0x2660 [scsi_transport_iscsi] [ 276.965153] iscsi_if_rx+0x198/0x4b0 [scsi_transport_iscsi] [ 276.965546] netlink_unicast+0x4d5/0x7b0 [ 276.965905] netlink_sendmsg+0x78d/0xc30 [ 276.966236] sock_sendmsg+0xe5/0x120 [ 276.966576] ____sys_sendmsg+0x5fe/0x860 [ 276.966923] ___sys_sendmsg+0xe0/0x170 [ 276.967300] __sys_sendmsg+0xc8/0x170 [ 276.967666] do_syscall_64+0x38/0x90 [ 276.968028] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 276.968773] Freed by task 2209: [ 276.969111] kasan_save_stack+0x1e/0x40 [ 276.969449] kasan_set_track+0x21/0x30 [ 276.969789] kasan_save_free_info+0x2a/0x50 [ 276.970146] __kasan_slab_free+0x106/0x190 [ 276.970470] __kmem_cache_free+0x133/0x270 [ 276.970816] device_release+0x98/0x210 [ 276.971145] kobject_cleanup+0x101/0x360 [ 276.971462] iscsi_session_teardown+0x3fb/0x530 [libiscsi] [ 276.971775] iscsi_sw_tcp_session_destroy+0xd8/0x130 [iscsi_tcp] [ 276.972143] iscsi_if_recv_msg+0x1bf1/0x2660 [scsi_transport_iscsi] [ 276.972485] iscsi_if_rx+0x198/0x4b0 [scsi_transport_iscsi] [ 276.972808] netlink_unicast+0x4d5/0x7b0 [ 276.973201] netlink_sendmsg+0x78d/0xc30 [ 276.973544] sock_sendmsg+0xe5/0x120 [ 276.973864] ____sys_sendmsg+0x5fe/0x860 [ 276.974248] ___sys_sendmsg+0xe0/0x170 [ 276.974583] __sys_sendmsg+0xc8/0x170 [ 276.974891] do_syscall_64+0x38/0x90 [ 276.975216] entry_SYSCALL_64_after_hwframe+0x63/0xcd We can easily reproduce by two tasks: 1. while :; do iscsiadm -m node --login; iscsiadm -m node --logout; done 2. while :; do cat \ /sys/devices/platform/host*/iscsi_host/host*/ipaddress; done iscsid | cat --------------------------------+--------------------------------------- |- iscsi_sw_tcp_session_destroy | |- iscsi_session_teardown | |- device_release | |- iscsi_session_release ||- dev_attr_show |- kfree | |- show_host_param_ | ISCSI_HOST_PARAM_IPADDRESS | |- iscsi_sw_tcp_host_get_param | |- r/w tcp_sw_host->session (UAF) |- iscsi_host_remove | |- iscsi_host_free | Fix the above bug by splitting the session removal into 2 parts: 1. removal from iSCSI class which includes sysfs and removal from host tracking. 2. freeing of session. During iscsi_tcp host and session removal we can remove the session from sysfs then remove the host from sysfs. At this point we know userspace is not accessing the kernel via sysfs so we can free the session and host. Link: https://lore.kernel.org/r/20230117193937.21244-2-michael.christie@oracle.com Signed-off-by: Mike Christie <michael.christie@oracle.com> Reviewed-by: Lee Duncan <lduncan@suse.com> Acked-by: Ding Hui <dinghui@sangfor.com.cn> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> (cherry picked from commit 6f1d64b) [Fixed to apply on 5.4] Signed-off-by: Puranjay Mohan <pjy@amazon.com>
nathan-zcgao
pushed a commit
that referenced
this pull request
Jun 27, 2025
Commit c68cf52 upstream Currently, when CONFIG_ARM64_PTR_AUTH_KERNEL=y (and CONFIG_UNWIND_PATCH_PAC_INTO_SCS=n), we enable pointer authentication for all functions, including leaf functions. This isn't necessary, and is unfortunate for a few reasons: * Any PACIASP instruction is implicitly a `BTI C` landing pad, and forcing the addition of a PACIASP in every function introduces a larger set of BTI gadgets than is necessary. * The PACIASP and AUTIASP instructions make leaf functions larger than necessary, bloating the kernel Image. For a defconfig v6.2-rc3 kernel, this appears to add ~64KiB relative to not signing leaf functions, which is unfortunate but not entirely onerous. * The PACIASP and AUTIASP instructions potentially make leaf functions more expensive in terms of performance and/or power. For many trivial leaf functions, this is clearly unnecessary, e.g. | <arch_local_save_flags>: | d503233f paciasp | d53b4220 mrs x0, daif | d50323bf autiasp | d65f03c0 ret | <calibration_delay_done>: | d503233f paciasp | d50323bf autiasp | d65f03c0 ret | d503201f nop * When CONFIG_UNWIND_PATCH_PAC_INTO_SCS=y we disable pointer authentication for leaf functions, so clearly this is not functionally necessary, indicates we have an inconsistent threat model, and convolutes the Makefile logic. We've used pointer authentication in leaf functions since the introduction of in-kernel pointer authentication in commit: 74afda4 ("arm64: compile the kernel with ptrauth return address signing") ... but at the time we had no rationale for signing leaf functions. Subsequently, we considered avoiding signing leaf functions: https://lore.kernel.org/linux-arm-kernel/1586856741-26839-1-git-send-email-amit.kachhap@arm.com/ https://lore.kernel.org/linux-arm-kernel/1588149371-20310-1-git-send-email-amit.kachhap@arm.com/ ... however at the time we didn't have an abundance of reasons to avoid signing leaf functions as above (e.g. the BTI case), we had no hardware to make performance measurements, and it was reasoned that this gave some level of protection against a limited set of code-reuse gadgets which would fall through to a RET. We documented this in commit: 717b938 ("arm64: Document why we enable PAC support for leaf functions") Notably, this was before we supported any forward-edge CFI scheme (e.g. Arm BTI, or Clang CFI/kCFI), which would prevent jumping into the middle of a function. In addition, even with signing forced for leaf functions, AUTIASP may be placed before a number of instructions which might constitute such a gadget, e.g. | <user_regs_reset_single_step>: | f9400022 ldr x2, [x1] | d503233f paciasp | d50323bf autiasp | f9408401 ldr x1, [x0, #264] | 720b005f tst w2, #0x200000 | b26b0022 orr x2, x1, #0x200000 | 926af821 and x1, x1, #0xffffffffffdfffff | 9a820021 csel x1, x1, x2, eq // eq = none | f9008401 str x1, [x0, #264] | d65f03c0 ret | <fpsimd_cpu_dead>: | 2a0003e3 mov w3, w0 | 9000ff42 adrp x2, ffff800009ffd000 <xen_dynamic_chip+0x48> | 9120e042 add x2, x2, #0x838 | 52800000 mov w0, #0x0 // #0 | d503233f paciasp | f000d041 adrp x1, ffff800009a20000 <this_cpu_vector> | d50323bf autiasp | 9102c021 add x1, x1, #0xb0 | f8635842 ldr x2, [x2, w3, uxtw #3] | f821685f str xzr, [x2, x1] | d65f03c0 ret | d503201f nop So generally, trying to use AUTIASP to detect such gadgetization is not robust, and this is dealt with far better by forward-edge CFI (which is designed to prevent such cases). We should bite the bullet and stop pretending that AUTIASP is a mitigation for such forward-edge gadgetization. For the above reasons, this patch has the kernel consistently sign non-leaf functions and avoid signing leaf functions. Considering a defconfig v6.2-rc3 kernel built with LLVM 15.0.6: * The vmlinux is ~43KiB smaller: | [mark@lakrids:~/src/linux]% ls -al vmlinux-* | -rwxr-xr-x 1 mark mark 338547808 Jan 25 17:17 vmlinux-after | -rwxr-xr-x 1 mark mark 338591472 Jan 25 17:22 vmlinux-before * The resulting Image is 64KiB smaller: | [mark@lakrids:~/src/linux]% ls -al Image-* | -rwxr-xr-x 1 mark mark 32702976 Jan 25 17:17 Image-after | -rwxr-xr-x 1 mark mark 32768512 Jan 25 17:22 Image-before * There are ~400 fewer BTI gadgets: | [mark@lakrids:~/src/linux]% usekorg 12.1.0 aarch64-linux-objdump -d vmlinux-before 2> /dev/null | grep -ow 'paciasp\|bti\sc\?' | sort | uniq -c | 1219 bti c | 61982 paciasp | [mark@lakrids:~/src/linux]% usekorg 12.1.0 aarch64-linux-objdump -d vmlinux-after 2> /dev/null | grep -ow 'paciasp\|bti\sc\?' | sort | uniq -c | 10099 bti c | 52699 paciasp Which is +8880 BTIs, and -9283 PACIASPs, for -403 unnecessary BTI gadgets. While this is small relative to the total, distinguishing the two cases will make it easier to analyse and reduce this set further in future. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Mark Brown <broonie@kernel.org> Cc: Amit Daniel Kachhap <amit.kachhap@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20230131105809.991288-3-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> [resolved conflicts] Signed-off-by: Mahmoud Adam <mngyadam@amazon.com>
nathan-zcgao
pushed a commit
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Jun 27, 2025
…ress Bug report and analysis from Ding Hui. During iSCSI session logout, if another task accesses the shost ipaddress attr, we can get a KASAN UAF report like this: [ 276.942144] BUG: KASAN: use-after-free in _raw_spin_lock_bh+0x78/0xe0 [ 276.942535] Write of size 4 at addr ffff8881053b45b8 by task cat/4088 [ 276.943511] CPU: 2 PID: 4088 Comm: cat Tainted: G E 6.1.0-rc8+ #3 [ 276.943997] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020 [ 276.944470] Call Trace: [ 276.944943] <TASK> [ 276.945397] dump_stack_lvl+0x34/0x48 [ 276.945887] print_address_description.constprop.0+0x86/0x1e7 [ 276.946421] print_report+0x36/0x4f [ 276.947358] kasan_report+0xad/0x130 [ 276.948234] kasan_check_range+0x35/0x1c0 [ 276.948674] _raw_spin_lock_bh+0x78/0xe0 [ 276.949989] iscsi_sw_tcp_host_get_param+0xad/0x2e0 [iscsi_tcp] [ 276.951765] show_host_param_ISCSI_HOST_PARAM_IPADDRESS+0xe9/0x130 [scsi_transport_iscsi] [ 276.952185] dev_attr_show+0x3f/0x80 [ 276.953005] sysfs_kf_seq_show+0x1fb/0x3e0 [ 276.953401] seq_read_iter+0x402/0x1020 [ 276.954260] vfs_read+0x532/0x7b0 [ 276.955113] ksys_read+0xed/0x1c0 [ 276.955952] do_syscall_64+0x38/0x90 [ 276.956347] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 276.956769] RIP: 0033:0x7f5d3a679222 [ 276.957161] Code: c0 e9 b2 fe ff ff 50 48 8d 3d 32 c0 0b 00 e8 a5 fe 01 00 0f 1f 44 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 0f 05 <48> 3d 00 f0 ff ff 77 56 c3 0f 1f 44 00 00 48 83 ec 28 48 89 54 24 [ 276.958009] RSP: 002b:00007ffc864d16a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 276.958431] RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f5d3a679222 [ 276.958857] RDX: 0000000000020000 RSI: 00007f5d3a4fe000 RDI: 0000000000000003 [ 276.959281] RBP: 00007f5d3a4fe000 R08: 00000000ffffffff R09: 0000000000000000 [ 276.959682] R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000020000 [ 276.960126] R13: 0000000000000003 R14: 0000000000000000 R15: 0000557a26dada58 [ 276.960536] </TASK> [ 276.961357] Allocated by task 2209: [ 276.961756] kasan_save_stack+0x1e/0x40 [ 276.962170] kasan_set_track+0x21/0x30 [ 276.962557] __kasan_kmalloc+0x7e/0x90 [ 276.962923] __kmalloc+0x5b/0x140 [ 276.963308] iscsi_alloc_session+0x28/0x840 [scsi_transport_iscsi] [ 276.963712] iscsi_session_setup+0xda/0xba0 [libiscsi] [ 276.964078] iscsi_sw_tcp_session_create+0x1fd/0x330 [iscsi_tcp] [ 276.964431] iscsi_if_create_session.isra.0+0x50/0x260 [scsi_transport_iscsi] [ 276.964793] iscsi_if_recv_msg+0xc5a/0x2660 [scsi_transport_iscsi] [ 276.965153] iscsi_if_rx+0x198/0x4b0 [scsi_transport_iscsi] [ 276.965546] netlink_unicast+0x4d5/0x7b0 [ 276.965905] netlink_sendmsg+0x78d/0xc30 [ 276.966236] sock_sendmsg+0xe5/0x120 [ 276.966576] ____sys_sendmsg+0x5fe/0x860 [ 276.966923] ___sys_sendmsg+0xe0/0x170 [ 276.967300] __sys_sendmsg+0xc8/0x170 [ 276.967666] do_syscall_64+0x38/0x90 [ 276.968028] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 276.968773] Freed by task 2209: [ 276.969111] kasan_save_stack+0x1e/0x40 [ 276.969449] kasan_set_track+0x21/0x30 [ 276.969789] kasan_save_free_info+0x2a/0x50 [ 276.970146] __kasan_slab_free+0x106/0x190 [ 276.970470] __kmem_cache_free+0x133/0x270 [ 276.970816] device_release+0x98/0x210 [ 276.971145] kobject_cleanup+0x101/0x360 [ 276.971462] iscsi_session_teardown+0x3fb/0x530 [libiscsi] [ 276.971775] iscsi_sw_tcp_session_destroy+0xd8/0x130 [iscsi_tcp] [ 276.972143] iscsi_if_recv_msg+0x1bf1/0x2660 [scsi_transport_iscsi] [ 276.972485] iscsi_if_rx+0x198/0x4b0 [scsi_transport_iscsi] [ 276.972808] netlink_unicast+0x4d5/0x7b0 [ 276.973201] netlink_sendmsg+0x78d/0xc30 [ 276.973544] sock_sendmsg+0xe5/0x120 [ 276.973864] ____sys_sendmsg+0x5fe/0x860 [ 276.974248] ___sys_sendmsg+0xe0/0x170 [ 276.974583] __sys_sendmsg+0xc8/0x170 [ 276.974891] do_syscall_64+0x38/0x90 [ 276.975216] entry_SYSCALL_64_after_hwframe+0x63/0xcd We can easily reproduce by two tasks: 1. while :; do iscsiadm -m node --login; iscsiadm -m node --logout; done 2. while :; do cat \ /sys/devices/platform/host*/iscsi_host/host*/ipaddress; done iscsid | cat --------------------------------+--------------------------------------- |- iscsi_sw_tcp_session_destroy | |- iscsi_session_teardown | |- device_release | |- iscsi_session_release ||- dev_attr_show |- kfree | |- show_host_param_ | ISCSI_HOST_PARAM_IPADDRESS | |- iscsi_sw_tcp_host_get_param | |- r/w tcp_sw_host->session (UAF) |- iscsi_host_remove | |- iscsi_host_free | Fix the above bug by splitting the session removal into 2 parts: 1. removal from iSCSI class which includes sysfs and removal from host tracking. 2. freeing of session. During iscsi_tcp host and session removal we can remove the session from sysfs then remove the host from sysfs. At this point we know userspace is not accessing the kernel via sysfs so we can free the session and host. Link: https://lore.kernel.org/r/20230117193937.21244-2-michael.christie@oracle.com Signed-off-by: Mike Christie <michael.christie@oracle.com> Reviewed-by: Lee Duncan <lduncan@suse.com> Acked-by: Ding Hui <dinghui@sangfor.com.cn> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> (cherry picked from commit 6f1d64b) [Fixed to apply on 5.10] Signed-off-by: Puranjay Mohan <pjy@amazon.com>
nathan-zcgao
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Jun 27, 2025
Commit c68cf52 upstream Currently, when CONFIG_ARM64_PTR_AUTH_KERNEL=y (and CONFIG_UNWIND_PATCH_PAC_INTO_SCS=n), we enable pointer authentication for all functions, including leaf functions. This isn't necessary, and is unfortunate for a few reasons: * Any PACIASP instruction is implicitly a `BTI C` landing pad, and forcing the addition of a PACIASP in every function introduces a larger set of BTI gadgets than is necessary. * The PACIASP and AUTIASP instructions make leaf functions larger than necessary, bloating the kernel Image. For a defconfig v6.2-rc3 kernel, this appears to add ~64KiB relative to not signing leaf functions, which is unfortunate but not entirely onerous. * The PACIASP and AUTIASP instructions potentially make leaf functions more expensive in terms of performance and/or power. For many trivial leaf functions, this is clearly unnecessary, e.g. | <arch_local_save_flags>: | d503233f paciasp | d53b4220 mrs x0, daif | d50323bf autiasp | d65f03c0 ret | <calibration_delay_done>: | d503233f paciasp | d50323bf autiasp | d65f03c0 ret | d503201f nop * When CONFIG_UNWIND_PATCH_PAC_INTO_SCS=y we disable pointer authentication for leaf functions, so clearly this is not functionally necessary, indicates we have an inconsistent threat model, and convolutes the Makefile logic. We've used pointer authentication in leaf functions since the introduction of in-kernel pointer authentication in commit: 74afda4 ("arm64: compile the kernel with ptrauth return address signing") ... but at the time we had no rationale for signing leaf functions. Subsequently, we considered avoiding signing leaf functions: https://lore.kernel.org/linux-arm-kernel/1586856741-26839-1-git-send-email-amit.kachhap@arm.com/ https://lore.kernel.org/linux-arm-kernel/1588149371-20310-1-git-send-email-amit.kachhap@arm.com/ ... however at the time we didn't have an abundance of reasons to avoid signing leaf functions as above (e.g. the BTI case), we had no hardware to make performance measurements, and it was reasoned that this gave some level of protection against a limited set of code-reuse gadgets which would fall through to a RET. We documented this in commit: 717b938 ("arm64: Document why we enable PAC support for leaf functions") Notably, this was before we supported any forward-edge CFI scheme (e.g. Arm BTI, or Clang CFI/kCFI), which would prevent jumping into the middle of a function. In addition, even with signing forced for leaf functions, AUTIASP may be placed before a number of instructions which might constitute such a gadget, e.g. | <user_regs_reset_single_step>: | f9400022 ldr x2, [x1] | d503233f paciasp | d50323bf autiasp | f9408401 ldr x1, [x0, #264] | 720b005f tst w2, #0x200000 | b26b0022 orr x2, x1, #0x200000 | 926af821 and x1, x1, #0xffffffffffdfffff | 9a820021 csel x1, x1, x2, eq // eq = none | f9008401 str x1, [x0, #264] | d65f03c0 ret | <fpsimd_cpu_dead>: | 2a0003e3 mov w3, w0 | 9000ff42 adrp x2, ffff800009ffd000 <xen_dynamic_chip+0x48> | 9120e042 add x2, x2, #0x838 | 52800000 mov w0, #0x0 // #0 | d503233f paciasp | f000d041 adrp x1, ffff800009a20000 <this_cpu_vector> | d50323bf autiasp | 9102c021 add x1, x1, #0xb0 | f8635842 ldr x2, [x2, w3, uxtw #3] | f821685f str xzr, [x2, x1] | d65f03c0 ret | d503201f nop So generally, trying to use AUTIASP to detect such gadgetization is not robust, and this is dealt with far better by forward-edge CFI (which is designed to prevent such cases). We should bite the bullet and stop pretending that AUTIASP is a mitigation for such forward-edge gadgetization. For the above reasons, this patch has the kernel consistently sign non-leaf functions and avoid signing leaf functions. Considering a defconfig v6.2-rc3 kernel built with LLVM 15.0.6: * The vmlinux is ~43KiB smaller: | [mark@lakrids:~/src/linux]% ls -al vmlinux-* | -rwxr-xr-x 1 mark mark 338547808 Jan 25 17:17 vmlinux-after | -rwxr-xr-x 1 mark mark 338591472 Jan 25 17:22 vmlinux-before * The resulting Image is 64KiB smaller: | [mark@lakrids:~/src/linux]% ls -al Image-* | -rwxr-xr-x 1 mark mark 32702976 Jan 25 17:17 Image-after | -rwxr-xr-x 1 mark mark 32768512 Jan 25 17:22 Image-before * There are ~400 fewer BTI gadgets: | [mark@lakrids:~/src/linux]% usekorg 12.1.0 aarch64-linux-objdump -d vmlinux-before 2> /dev/null | grep -ow 'paciasp\|bti\sc\?' | sort | uniq -c | 1219 bti c | 61982 paciasp | [mark@lakrids:~/src/linux]% usekorg 12.1.0 aarch64-linux-objdump -d vmlinux-after 2> /dev/null | grep -ow 'paciasp\|bti\sc\?' | sort | uniq -c | 10099 bti c | 52699 paciasp Which is +8880 BTIs, and -9283 PACIASPs, for -403 unnecessary BTI gadgets. While this is small relative to the total, distinguishing the two cases will make it easier to analyse and reduce this set further in future. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Mark Brown <broonie@kernel.org> Cc: Amit Daniel Kachhap <amit.kachhap@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20230131105809.991288-3-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> [resolved conflicts] Signed-off-by: Mahmoud Adam <mngyadam@amazon.com>
nathan-zcgao
pushed a commit
that referenced
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Jun 27, 2025
…ress Bug report and analysis from Ding Hui. During iSCSI session logout, if another task accesses the shost ipaddress attr, we can get a KASAN UAF report like this: [ 276.942144] BUG: KASAN: use-after-free in _raw_spin_lock_bh+0x78/0xe0 [ 276.942535] Write of size 4 at addr ffff8881053b45b8 by task cat/4088 [ 276.943511] CPU: 2 PID: 4088 Comm: cat Tainted: G E 6.1.0-rc8+ #3 [ 276.943997] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020 [ 276.944470] Call Trace: [ 276.944943] <TASK> [ 276.945397] dump_stack_lvl+0x34/0x48 [ 276.945887] print_address_description.constprop.0+0x86/0x1e7 [ 276.946421] print_report+0x36/0x4f [ 276.947358] kasan_report+0xad/0x130 [ 276.948234] kasan_check_range+0x35/0x1c0 [ 276.948674] _raw_spin_lock_bh+0x78/0xe0 [ 276.949989] iscsi_sw_tcp_host_get_param+0xad/0x2e0 [iscsi_tcp] [ 276.951765] show_host_param_ISCSI_HOST_PARAM_IPADDRESS+0xe9/0x130 [scsi_transport_iscsi] [ 276.952185] dev_attr_show+0x3f/0x80 [ 276.953005] sysfs_kf_seq_show+0x1fb/0x3e0 [ 276.953401] seq_read_iter+0x402/0x1020 [ 276.954260] vfs_read+0x532/0x7b0 [ 276.955113] ksys_read+0xed/0x1c0 [ 276.955952] do_syscall_64+0x38/0x90 [ 276.956347] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 276.956769] RIP: 0033:0x7f5d3a679222 [ 276.957161] Code: c0 e9 b2 fe ff ff 50 48 8d 3d 32 c0 0b 00 e8 a5 fe 01 00 0f 1f 44 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 0f 05 <48> 3d 00 f0 ff ff 77 56 c3 0f 1f 44 00 00 48 83 ec 28 48 89 54 24 [ 276.958009] RSP: 002b:00007ffc864d16a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 276.958431] RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f5d3a679222 [ 276.958857] RDX: 0000000000020000 RSI: 00007f5d3a4fe000 RDI: 0000000000000003 [ 276.959281] RBP: 00007f5d3a4fe000 R08: 00000000ffffffff R09: 0000000000000000 [ 276.959682] R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000020000 [ 276.960126] R13: 0000000000000003 R14: 0000000000000000 R15: 0000557a26dada58 [ 276.960536] </TASK> [ 276.961357] Allocated by task 2209: [ 276.961756] kasan_save_stack+0x1e/0x40 [ 276.962170] kasan_set_track+0x21/0x30 [ 276.962557] __kasan_kmalloc+0x7e/0x90 [ 276.962923] __kmalloc+0x5b/0x140 [ 276.963308] iscsi_alloc_session+0x28/0x840 [scsi_transport_iscsi] [ 276.963712] iscsi_session_setup+0xda/0xba0 [libiscsi] [ 276.964078] iscsi_sw_tcp_session_create+0x1fd/0x330 [iscsi_tcp] [ 276.964431] iscsi_if_create_session.isra.0+0x50/0x260 [scsi_transport_iscsi] [ 276.964793] iscsi_if_recv_msg+0xc5a/0x2660 [scsi_transport_iscsi] [ 276.965153] iscsi_if_rx+0x198/0x4b0 [scsi_transport_iscsi] [ 276.965546] netlink_unicast+0x4d5/0x7b0 [ 276.965905] netlink_sendmsg+0x78d/0xc30 [ 276.966236] sock_sendmsg+0xe5/0x120 [ 276.966576] ____sys_sendmsg+0x5fe/0x860 [ 276.966923] ___sys_sendmsg+0xe0/0x170 [ 276.967300] __sys_sendmsg+0xc8/0x170 [ 276.967666] do_syscall_64+0x38/0x90 [ 276.968028] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 276.968773] Freed by task 2209: [ 276.969111] kasan_save_stack+0x1e/0x40 [ 276.969449] kasan_set_track+0x21/0x30 [ 276.969789] kasan_save_free_info+0x2a/0x50 [ 276.970146] __kasan_slab_free+0x106/0x190 [ 276.970470] __kmem_cache_free+0x133/0x270 [ 276.970816] device_release+0x98/0x210 [ 276.971145] kobject_cleanup+0x101/0x360 [ 276.971462] iscsi_session_teardown+0x3fb/0x530 [libiscsi] [ 276.971775] iscsi_sw_tcp_session_destroy+0xd8/0x130 [iscsi_tcp] [ 276.972143] iscsi_if_recv_msg+0x1bf1/0x2660 [scsi_transport_iscsi] [ 276.972485] iscsi_if_rx+0x198/0x4b0 [scsi_transport_iscsi] [ 276.972808] netlink_unicast+0x4d5/0x7b0 [ 276.973201] netlink_sendmsg+0x78d/0xc30 [ 276.973544] sock_sendmsg+0xe5/0x120 [ 276.973864] ____sys_sendmsg+0x5fe/0x860 [ 276.974248] ___sys_sendmsg+0xe0/0x170 [ 276.974583] __sys_sendmsg+0xc8/0x170 [ 276.974891] do_syscall_64+0x38/0x90 [ 276.975216] entry_SYSCALL_64_after_hwframe+0x63/0xcd We can easily reproduce by two tasks: 1. while :; do iscsiadm -m node --login; iscsiadm -m node --logout; done 2. while :; do cat \ /sys/devices/platform/host*/iscsi_host/host*/ipaddress; done iscsid | cat --------------------------------+--------------------------------------- |- iscsi_sw_tcp_session_destroy | |- iscsi_session_teardown | |- device_release | |- iscsi_session_release ||- dev_attr_show |- kfree | |- show_host_param_ | ISCSI_HOST_PARAM_IPADDRESS | |- iscsi_sw_tcp_host_get_param | |- r/w tcp_sw_host->session (UAF) |- iscsi_host_remove | |- iscsi_host_free | Fix the above bug by splitting the session removal into 2 parts: 1. removal from iSCSI class which includes sysfs and removal from host tracking. 2. freeing of session. During iscsi_tcp host and session removal we can remove the session from sysfs then remove the host from sysfs. At this point we know userspace is not accessing the kernel via sysfs so we can free the session and host. Link: https://lore.kernel.org/r/20230117193937.21244-2-michael.christie@oracle.com Signed-off-by: Mike Christie <michael.christie@oracle.com> Reviewed-by: Lee Duncan <lduncan@suse.com> Acked-by: Ding Hui <dinghui@sangfor.com.cn> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> (cherry picked from commit 6f1d64b) [Fixed to apply on 5.10] Signed-off-by: Puranjay Mohan <pjy@amazon.com>
aahmed71
pushed a commit
that referenced
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Jun 28, 2025
…ress Bug report and analysis from Ding Hui. During iSCSI session logout, if another task accesses the shost ipaddress attr, we can get a KASAN UAF report like this: [ 276.942144] BUG: KASAN: use-after-free in _raw_spin_lock_bh+0x78/0xe0 [ 276.942535] Write of size 4 at addr ffff8881053b45b8 by task cat/4088 [ 276.943511] CPU: 2 PID: 4088 Comm: cat Tainted: G E 6.1.0-rc8+ #3 [ 276.943997] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020 [ 276.944470] Call Trace: [ 276.944943] <TASK> [ 276.945397] dump_stack_lvl+0x34/0x48 [ 276.945887] print_address_description.constprop.0+0x86/0x1e7 [ 276.946421] print_report+0x36/0x4f [ 276.947358] kasan_report+0xad/0x130 [ 276.948234] kasan_check_range+0x35/0x1c0 [ 276.948674] _raw_spin_lock_bh+0x78/0xe0 [ 276.949989] iscsi_sw_tcp_host_get_param+0xad/0x2e0 [iscsi_tcp] [ 276.951765] show_host_param_ISCSI_HOST_PARAM_IPADDRESS+0xe9/0x130 [scsi_transport_iscsi] [ 276.952185] dev_attr_show+0x3f/0x80 [ 276.953005] sysfs_kf_seq_show+0x1fb/0x3e0 [ 276.953401] seq_read_iter+0x402/0x1020 [ 276.954260] vfs_read+0x532/0x7b0 [ 276.955113] ksys_read+0xed/0x1c0 [ 276.955952] do_syscall_64+0x38/0x90 [ 276.956347] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 276.956769] RIP: 0033:0x7f5d3a679222 [ 276.957161] Code: c0 e9 b2 fe ff ff 50 48 8d 3d 32 c0 0b 00 e8 a5 fe 01 00 0f 1f 44 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 0f 05 <48> 3d 00 f0 ff ff 77 56 c3 0f 1f 44 00 00 48 83 ec 28 48 89 54 24 [ 276.958009] RSP: 002b:00007ffc864d16a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 276.958431] RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f5d3a679222 [ 276.958857] RDX: 0000000000020000 RSI: 00007f5d3a4fe000 RDI: 0000000000000003 [ 276.959281] RBP: 00007f5d3a4fe000 R08: 00000000ffffffff R09: 0000000000000000 [ 276.959682] R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000020000 [ 276.960126] R13: 0000000000000003 R14: 0000000000000000 R15: 0000557a26dada58 [ 276.960536] </TASK> [ 276.961357] Allocated by task 2209: [ 276.961756] kasan_save_stack+0x1e/0x40 [ 276.962170] kasan_set_track+0x21/0x30 [ 276.962557] __kasan_kmalloc+0x7e/0x90 [ 276.962923] __kmalloc+0x5b/0x140 [ 276.963308] iscsi_alloc_session+0x28/0x840 [scsi_transport_iscsi] [ 276.963712] iscsi_session_setup+0xda/0xba0 [libiscsi] [ 276.964078] iscsi_sw_tcp_session_create+0x1fd/0x330 [iscsi_tcp] [ 276.964431] iscsi_if_create_session.isra.0+0x50/0x260 [scsi_transport_iscsi] [ 276.964793] iscsi_if_recv_msg+0xc5a/0x2660 [scsi_transport_iscsi] [ 276.965153] iscsi_if_rx+0x198/0x4b0 [scsi_transport_iscsi] [ 276.965546] netlink_unicast+0x4d5/0x7b0 [ 276.965905] netlink_sendmsg+0x78d/0xc30 [ 276.966236] sock_sendmsg+0xe5/0x120 [ 276.966576] ____sys_sendmsg+0x5fe/0x860 [ 276.966923] ___sys_sendmsg+0xe0/0x170 [ 276.967300] __sys_sendmsg+0xc8/0x170 [ 276.967666] do_syscall_64+0x38/0x90 [ 276.968028] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 276.968773] Freed by task 2209: [ 276.969111] kasan_save_stack+0x1e/0x40 [ 276.969449] kasan_set_track+0x21/0x30 [ 276.969789] kasan_save_free_info+0x2a/0x50 [ 276.970146] __kasan_slab_free+0x106/0x190 [ 276.970470] __kmem_cache_free+0x133/0x270 [ 276.970816] device_release+0x98/0x210 [ 276.971145] kobject_cleanup+0x101/0x360 [ 276.971462] iscsi_session_teardown+0x3fb/0x530 [libiscsi] [ 276.971775] iscsi_sw_tcp_session_destroy+0xd8/0x130 [iscsi_tcp] [ 276.972143] iscsi_if_recv_msg+0x1bf1/0x2660 [scsi_transport_iscsi] [ 276.972485] iscsi_if_rx+0x198/0x4b0 [scsi_transport_iscsi] [ 276.972808] netlink_unicast+0x4d5/0x7b0 [ 276.973201] netlink_sendmsg+0x78d/0xc30 [ 276.973544] sock_sendmsg+0xe5/0x120 [ 276.973864] ____sys_sendmsg+0x5fe/0x860 [ 276.974248] ___sys_sendmsg+0xe0/0x170 [ 276.974583] __sys_sendmsg+0xc8/0x170 [ 276.974891] do_syscall_64+0x38/0x90 [ 276.975216] entry_SYSCALL_64_after_hwframe+0x63/0xcd We can easily reproduce by two tasks: 1. while :; do iscsiadm -m node --login; iscsiadm -m node --logout; done 2. while :; do cat \ /sys/devices/platform/host*/iscsi_host/host*/ipaddress; done iscsid | cat --------------------------------+--------------------------------------- |- iscsi_sw_tcp_session_destroy | |- iscsi_session_teardown | |- device_release | |- iscsi_session_release ||- dev_attr_show |- kfree | |- show_host_param_ | ISCSI_HOST_PARAM_IPADDRESS | |- iscsi_sw_tcp_host_get_param | |- r/w tcp_sw_host->session (UAF) |- iscsi_host_remove | |- iscsi_host_free | Fix the above bug by splitting the session removal into 2 parts: 1. removal from iSCSI class which includes sysfs and removal from host tracking. 2. freeing of session. During iscsi_tcp host and session removal we can remove the session from sysfs then remove the host from sysfs. At this point we know userspace is not accessing the kernel via sysfs so we can free the session and host. Link: https://lore.kernel.org/r/20230117193937.21244-2-michael.christie@oracle.com Signed-off-by: Mike Christie <michael.christie@oracle.com> Reviewed-by: Lee Duncan <lduncan@suse.com> Acked-by: Ding Hui <dinghui@sangfor.com.cn> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> (cherry picked from commit 6f1d64b) [fixed to apply on 4.14] Signed-off-by: Puranjay Mohan <pjy@amazon.com>
aahmed71
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Jul 1, 2025
Commit c68cf52 upstream Currently, when CONFIG_ARM64_PTR_AUTH_KERNEL=y (and CONFIG_UNWIND_PATCH_PAC_INTO_SCS=n), we enable pointer authentication for all functions, including leaf functions. This isn't necessary, and is unfortunate for a few reasons: * Any PACIASP instruction is implicitly a `BTI C` landing pad, and forcing the addition of a PACIASP in every function introduces a larger set of BTI gadgets than is necessary. * The PACIASP and AUTIASP instructions make leaf functions larger than necessary, bloating the kernel Image. For a defconfig v6.2-rc3 kernel, this appears to add ~64KiB relative to not signing leaf functions, which is unfortunate but not entirely onerous. * The PACIASP and AUTIASP instructions potentially make leaf functions more expensive in terms of performance and/or power. For many trivial leaf functions, this is clearly unnecessary, e.g. | <arch_local_save_flags>: | d503233f paciasp | d53b4220 mrs x0, daif | d50323bf autiasp | d65f03c0 ret | <calibration_delay_done>: | d503233f paciasp | d50323bf autiasp | d65f03c0 ret | d503201f nop * When CONFIG_UNWIND_PATCH_PAC_INTO_SCS=y we disable pointer authentication for leaf functions, so clearly this is not functionally necessary, indicates we have an inconsistent threat model, and convolutes the Makefile logic. We've used pointer authentication in leaf functions since the introduction of in-kernel pointer authentication in commit: 74afda4 ("arm64: compile the kernel with ptrauth return address signing") ... but at the time we had no rationale for signing leaf functions. Subsequently, we considered avoiding signing leaf functions: https://lore.kernel.org/linux-arm-kernel/1586856741-26839-1-git-send-email-amit.kachhap@arm.com/ https://lore.kernel.org/linux-arm-kernel/1588149371-20310-1-git-send-email-amit.kachhap@arm.com/ ... however at the time we didn't have an abundance of reasons to avoid signing leaf functions as above (e.g. the BTI case), we had no hardware to make performance measurements, and it was reasoned that this gave some level of protection against a limited set of code-reuse gadgets which would fall through to a RET. We documented this in commit: 717b938 ("arm64: Document why we enable PAC support for leaf functions") Notably, this was before we supported any forward-edge CFI scheme (e.g. Arm BTI, or Clang CFI/kCFI), which would prevent jumping into the middle of a function. In addition, even with signing forced for leaf functions, AUTIASP may be placed before a number of instructions which might constitute such a gadget, e.g. | <user_regs_reset_single_step>: | f9400022 ldr x2, [x1] | d503233f paciasp | d50323bf autiasp | f9408401 ldr x1, [x0, #264] | 720b005f tst w2, #0x200000 | b26b0022 orr x2, x1, #0x200000 | 926af821 and x1, x1, #0xffffffffffdfffff | 9a820021 csel x1, x1, x2, eq // eq = none | f9008401 str x1, [x0, #264] | d65f03c0 ret | <fpsimd_cpu_dead>: | 2a0003e3 mov w3, w0 | 9000ff42 adrp x2, ffff800009ffd000 <xen_dynamic_chip+0x48> | 9120e042 add x2, x2, #0x838 | 52800000 mov w0, #0x0 // #0 | d503233f paciasp | f000d041 adrp x1, ffff800009a20000 <this_cpu_vector> | d50323bf autiasp | 9102c021 add x1, x1, #0xb0 | f8635842 ldr x2, [x2, w3, uxtw #3] | f821685f str xzr, [x2, x1] | d65f03c0 ret | d503201f nop So generally, trying to use AUTIASP to detect such gadgetization is not robust, and this is dealt with far better by forward-edge CFI (which is designed to prevent such cases). We should bite the bullet and stop pretending that AUTIASP is a mitigation for such forward-edge gadgetization. For the above reasons, this patch has the kernel consistently sign non-leaf functions and avoid signing leaf functions. Considering a defconfig v6.2-rc3 kernel built with LLVM 15.0.6: * The vmlinux is ~43KiB smaller: | [mark@lakrids:~/src/linux]% ls -al vmlinux-* | -rwxr-xr-x 1 mark mark 338547808 Jan 25 17:17 vmlinux-after | -rwxr-xr-x 1 mark mark 338591472 Jan 25 17:22 vmlinux-before * The resulting Image is 64KiB smaller: | [mark@lakrids:~/src/linux]% ls -al Image-* | -rwxr-xr-x 1 mark mark 32702976 Jan 25 17:17 Image-after | -rwxr-xr-x 1 mark mark 32768512 Jan 25 17:22 Image-before * There are ~400 fewer BTI gadgets: | [mark@lakrids:~/src/linux]% usekorg 12.1.0 aarch64-linux-objdump -d vmlinux-before 2> /dev/null | grep -ow 'paciasp\|bti\sc\?' | sort | uniq -c | 1219 bti c | 61982 paciasp | [mark@lakrids:~/src/linux]% usekorg 12.1.0 aarch64-linux-objdump -d vmlinux-after 2> /dev/null | grep -ow 'paciasp\|bti\sc\?' | sort | uniq -c | 10099 bti c | 52699 paciasp Which is +8880 BTIs, and -9283 PACIASPs, for -403 unnecessary BTI gadgets. While this is small relative to the total, distinguishing the two cases will make it easier to analyse and reduce this set further in future. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Mark Brown <broonie@kernel.org> Cc: Amit Daniel Kachhap <amit.kachhap@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20230131105809.991288-3-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> [resolved conflicts] Signed-off-by: Mahmoud Adam <mngyadam@amazon.com>
heynemax
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Jul 1, 2025
…ress Bug report and analysis from Ding Hui. During iSCSI session logout, if another task accesses the shost ipaddress attr, we can get a KASAN UAF report like this: [ 276.942144] BUG: KASAN: use-after-free in _raw_spin_lock_bh+0x78/0xe0 [ 276.942535] Write of size 4 at addr ffff8881053b45b8 by task cat/4088 [ 276.943511] CPU: 2 PID: 4088 Comm: cat Tainted: G E 6.1.0-rc8+ #3 [ 276.943997] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020 [ 276.944470] Call Trace: [ 276.944943] <TASK> [ 276.945397] dump_stack_lvl+0x34/0x48 [ 276.945887] print_address_description.constprop.0+0x86/0x1e7 [ 276.946421] print_report+0x36/0x4f [ 276.947358] kasan_report+0xad/0x130 [ 276.948234] kasan_check_range+0x35/0x1c0 [ 276.948674] _raw_spin_lock_bh+0x78/0xe0 [ 276.949989] iscsi_sw_tcp_host_get_param+0xad/0x2e0 [iscsi_tcp] [ 276.951765] show_host_param_ISCSI_HOST_PARAM_IPADDRESS+0xe9/0x130 [scsi_transport_iscsi] [ 276.952185] dev_attr_show+0x3f/0x80 [ 276.953005] sysfs_kf_seq_show+0x1fb/0x3e0 [ 276.953401] seq_read_iter+0x402/0x1020 [ 276.954260] vfs_read+0x532/0x7b0 [ 276.955113] ksys_read+0xed/0x1c0 [ 276.955952] do_syscall_64+0x38/0x90 [ 276.956347] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 276.956769] RIP: 0033:0x7f5d3a679222 [ 276.957161] Code: c0 e9 b2 fe ff ff 50 48 8d 3d 32 c0 0b 00 e8 a5 fe 01 00 0f 1f 44 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 0f 05 <48> 3d 00 f0 ff ff 77 56 c3 0f 1f 44 00 00 48 83 ec 28 48 89 54 24 [ 276.958009] RSP: 002b:00007ffc864d16a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 276.958431] RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f5d3a679222 [ 276.958857] RDX: 0000000000020000 RSI: 00007f5d3a4fe000 RDI: 0000000000000003 [ 276.959281] RBP: 00007f5d3a4fe000 R08: 00000000ffffffff R09: 0000000000000000 [ 276.959682] R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000020000 [ 276.960126] R13: 0000000000000003 R14: 0000000000000000 R15: 0000557a26dada58 [ 276.960536] </TASK> [ 276.961357] Allocated by task 2209: [ 276.961756] kasan_save_stack+0x1e/0x40 [ 276.962170] kasan_set_track+0x21/0x30 [ 276.962557] __kasan_kmalloc+0x7e/0x90 [ 276.962923] __kmalloc+0x5b/0x140 [ 276.963308] iscsi_alloc_session+0x28/0x840 [scsi_transport_iscsi] [ 276.963712] iscsi_session_setup+0xda/0xba0 [libiscsi] [ 276.964078] iscsi_sw_tcp_session_create+0x1fd/0x330 [iscsi_tcp] [ 276.964431] iscsi_if_create_session.isra.0+0x50/0x260 [scsi_transport_iscsi] [ 276.964793] iscsi_if_recv_msg+0xc5a/0x2660 [scsi_transport_iscsi] [ 276.965153] iscsi_if_rx+0x198/0x4b0 [scsi_transport_iscsi] [ 276.965546] netlink_unicast+0x4d5/0x7b0 [ 276.965905] netlink_sendmsg+0x78d/0xc30 [ 276.966236] sock_sendmsg+0xe5/0x120 [ 276.966576] ____sys_sendmsg+0x5fe/0x860 [ 276.966923] ___sys_sendmsg+0xe0/0x170 [ 276.967300] __sys_sendmsg+0xc8/0x170 [ 276.967666] do_syscall_64+0x38/0x90 [ 276.968028] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 276.968773] Freed by task 2209: [ 276.969111] kasan_save_stack+0x1e/0x40 [ 276.969449] kasan_set_track+0x21/0x30 [ 276.969789] kasan_save_free_info+0x2a/0x50 [ 276.970146] __kasan_slab_free+0x106/0x190 [ 276.970470] __kmem_cache_free+0x133/0x270 [ 276.970816] device_release+0x98/0x210 [ 276.971145] kobject_cleanup+0x101/0x360 [ 276.971462] iscsi_session_teardown+0x3fb/0x530 [libiscsi] [ 276.971775] iscsi_sw_tcp_session_destroy+0xd8/0x130 [iscsi_tcp] [ 276.972143] iscsi_if_recv_msg+0x1bf1/0x2660 [scsi_transport_iscsi] [ 276.972485] iscsi_if_rx+0x198/0x4b0 [scsi_transport_iscsi] [ 276.972808] netlink_unicast+0x4d5/0x7b0 [ 276.973201] netlink_sendmsg+0x78d/0xc30 [ 276.973544] sock_sendmsg+0xe5/0x120 [ 276.973864] ____sys_sendmsg+0x5fe/0x860 [ 276.974248] ___sys_sendmsg+0xe0/0x170 [ 276.974583] __sys_sendmsg+0xc8/0x170 [ 276.974891] do_syscall_64+0x38/0x90 [ 276.975216] entry_SYSCALL_64_after_hwframe+0x63/0xcd We can easily reproduce by two tasks: 1. while :; do iscsiadm -m node --login; iscsiadm -m node --logout; done 2. while :; do cat \ /sys/devices/platform/host*/iscsi_host/host*/ipaddress; done iscsid | cat --------------------------------+--------------------------------------- |- iscsi_sw_tcp_session_destroy | |- iscsi_session_teardown | |- device_release | |- iscsi_session_release ||- dev_attr_show |- kfree | |- show_host_param_ | ISCSI_HOST_PARAM_IPADDRESS | |- iscsi_sw_tcp_host_get_param | |- r/w tcp_sw_host->session (UAF) |- iscsi_host_remove | |- iscsi_host_free | Fix the above bug by splitting the session removal into 2 parts: 1. removal from iSCSI class which includes sysfs and removal from host tracking. 2. freeing of session. During iscsi_tcp host and session removal we can remove the session from sysfs then remove the host from sysfs. At this point we know userspace is not accessing the kernel via sysfs so we can free the session and host. Link: https://lore.kernel.org/r/20230117193937.21244-2-michael.christie@oracle.com Signed-off-by: Mike Christie <michael.christie@oracle.com> Reviewed-by: Lee Duncan <lduncan@suse.com> Acked-by: Ding Hui <dinghui@sangfor.com.cn> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> (cherry picked from commit 6f1d64b) [Fixed to apply on 5.4] Signed-off-by: Puranjay Mohan <pjy@amazon.com>
heynemax
pushed a commit
that referenced
this pull request
Jul 1, 2025
…ress Bug report and analysis from Ding Hui. During iSCSI session logout, if another task accesses the shost ipaddress attr, we can get a KASAN UAF report like this: [ 276.942144] BUG: KASAN: use-after-free in _raw_spin_lock_bh+0x78/0xe0 [ 276.942535] Write of size 4 at addr ffff8881053b45b8 by task cat/4088 [ 276.943511] CPU: 2 PID: 4088 Comm: cat Tainted: G E 6.1.0-rc8+ #3 [ 276.943997] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020 [ 276.944470] Call Trace: [ 276.944943] <TASK> [ 276.945397] dump_stack_lvl+0x34/0x48 [ 276.945887] print_address_description.constprop.0+0x86/0x1e7 [ 276.946421] print_report+0x36/0x4f [ 276.947358] kasan_report+0xad/0x130 [ 276.948234] kasan_check_range+0x35/0x1c0 [ 276.948674] _raw_spin_lock_bh+0x78/0xe0 [ 276.949989] iscsi_sw_tcp_host_get_param+0xad/0x2e0 [iscsi_tcp] [ 276.951765] show_host_param_ISCSI_HOST_PARAM_IPADDRESS+0xe9/0x130 [scsi_transport_iscsi] [ 276.952185] dev_attr_show+0x3f/0x80 [ 276.953005] sysfs_kf_seq_show+0x1fb/0x3e0 [ 276.953401] seq_read_iter+0x402/0x1020 [ 276.954260] vfs_read+0x532/0x7b0 [ 276.955113] ksys_read+0xed/0x1c0 [ 276.955952] do_syscall_64+0x38/0x90 [ 276.956347] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 276.956769] RIP: 0033:0x7f5d3a679222 [ 276.957161] Code: c0 e9 b2 fe ff ff 50 48 8d 3d 32 c0 0b 00 e8 a5 fe 01 00 0f 1f 44 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 0f 05 <48> 3d 00 f0 ff ff 77 56 c3 0f 1f 44 00 00 48 83 ec 28 48 89 54 24 [ 276.958009] RSP: 002b:00007ffc864d16a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 276.958431] RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f5d3a679222 [ 276.958857] RDX: 0000000000020000 RSI: 00007f5d3a4fe000 RDI: 0000000000000003 [ 276.959281] RBP: 00007f5d3a4fe000 R08: 00000000ffffffff R09: 0000000000000000 [ 276.959682] R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000020000 [ 276.960126] R13: 0000000000000003 R14: 0000000000000000 R15: 0000557a26dada58 [ 276.960536] </TASK> [ 276.961357] Allocated by task 2209: [ 276.961756] kasan_save_stack+0x1e/0x40 [ 276.962170] kasan_set_track+0x21/0x30 [ 276.962557] __kasan_kmalloc+0x7e/0x90 [ 276.962923] __kmalloc+0x5b/0x140 [ 276.963308] iscsi_alloc_session+0x28/0x840 [scsi_transport_iscsi] [ 276.963712] iscsi_session_setup+0xda/0xba0 [libiscsi] [ 276.964078] iscsi_sw_tcp_session_create+0x1fd/0x330 [iscsi_tcp] [ 276.964431] iscsi_if_create_session.isra.0+0x50/0x260 [scsi_transport_iscsi] [ 276.964793] iscsi_if_recv_msg+0xc5a/0x2660 [scsi_transport_iscsi] [ 276.965153] iscsi_if_rx+0x198/0x4b0 [scsi_transport_iscsi] [ 276.965546] netlink_unicast+0x4d5/0x7b0 [ 276.965905] netlink_sendmsg+0x78d/0xc30 [ 276.966236] sock_sendmsg+0xe5/0x120 [ 276.966576] ____sys_sendmsg+0x5fe/0x860 [ 276.966923] ___sys_sendmsg+0xe0/0x170 [ 276.967300] __sys_sendmsg+0xc8/0x170 [ 276.967666] do_syscall_64+0x38/0x90 [ 276.968028] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 276.968773] Freed by task 2209: [ 276.969111] kasan_save_stack+0x1e/0x40 [ 276.969449] kasan_set_track+0x21/0x30 [ 276.969789] kasan_save_free_info+0x2a/0x50 [ 276.970146] __kasan_slab_free+0x106/0x190 [ 276.970470] __kmem_cache_free+0x133/0x270 [ 276.970816] device_release+0x98/0x210 [ 276.971145] kobject_cleanup+0x101/0x360 [ 276.971462] iscsi_session_teardown+0x3fb/0x530 [libiscsi] [ 276.971775] iscsi_sw_tcp_session_destroy+0xd8/0x130 [iscsi_tcp] [ 276.972143] iscsi_if_recv_msg+0x1bf1/0x2660 [scsi_transport_iscsi] [ 276.972485] iscsi_if_rx+0x198/0x4b0 [scsi_transport_iscsi] [ 276.972808] netlink_unicast+0x4d5/0x7b0 [ 276.973201] netlink_sendmsg+0x78d/0xc30 [ 276.973544] sock_sendmsg+0xe5/0x120 [ 276.973864] ____sys_sendmsg+0x5fe/0x860 [ 276.974248] ___sys_sendmsg+0xe0/0x170 [ 276.974583] __sys_sendmsg+0xc8/0x170 [ 276.974891] do_syscall_64+0x38/0x90 [ 276.975216] entry_SYSCALL_64_after_hwframe+0x63/0xcd We can easily reproduce by two tasks: 1. while :; do iscsiadm -m node --login; iscsiadm -m node --logout; done 2. while :; do cat \ /sys/devices/platform/host*/iscsi_host/host*/ipaddress; done iscsid | cat --------------------------------+--------------------------------------- |- iscsi_sw_tcp_session_destroy | |- iscsi_session_teardown | |- device_release | |- iscsi_session_release ||- dev_attr_show |- kfree | |- show_host_param_ | ISCSI_HOST_PARAM_IPADDRESS | |- iscsi_sw_tcp_host_get_param | |- r/w tcp_sw_host->session (UAF) |- iscsi_host_remove | |- iscsi_host_free | Fix the above bug by splitting the session removal into 2 parts: 1. removal from iSCSI class which includes sysfs and removal from host tracking. 2. freeing of session. During iscsi_tcp host and session removal we can remove the session from sysfs then remove the host from sysfs. At this point we know userspace is not accessing the kernel via sysfs so we can free the session and host. Link: https://lore.kernel.org/r/20230117193937.21244-2-michael.christie@oracle.com Signed-off-by: Mike Christie <michael.christie@oracle.com> Reviewed-by: Lee Duncan <lduncan@suse.com> Acked-by: Ding Hui <dinghui@sangfor.com.cn> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> (cherry picked from commit 6f1d64b) [Fixed to apply on 5.4] Signed-off-by: Puranjay Mohan <pjy@amazon.com>
aahmed71
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Jul 1, 2025
Commit c68cf52 upstream Currently, when CONFIG_ARM64_PTR_AUTH_KERNEL=y (and CONFIG_UNWIND_PATCH_PAC_INTO_SCS=n), we enable pointer authentication for all functions, including leaf functions. This isn't necessary, and is unfortunate for a few reasons: * Any PACIASP instruction is implicitly a `BTI C` landing pad, and forcing the addition of a PACIASP in every function introduces a larger set of BTI gadgets than is necessary. * The PACIASP and AUTIASP instructions make leaf functions larger than necessary, bloating the kernel Image. For a defconfig v6.2-rc3 kernel, this appears to add ~64KiB relative to not signing leaf functions, which is unfortunate but not entirely onerous. * The PACIASP and AUTIASP instructions potentially make leaf functions more expensive in terms of performance and/or power. For many trivial leaf functions, this is clearly unnecessary, e.g. | <arch_local_save_flags>: | d503233f paciasp | d53b4220 mrs x0, daif | d50323bf autiasp | d65f03c0 ret | <calibration_delay_done>: | d503233f paciasp | d50323bf autiasp | d65f03c0 ret | d503201f nop * When CONFIG_UNWIND_PATCH_PAC_INTO_SCS=y we disable pointer authentication for leaf functions, so clearly this is not functionally necessary, indicates we have an inconsistent threat model, and convolutes the Makefile logic. We've used pointer authentication in leaf functions since the introduction of in-kernel pointer authentication in commit: 74afda4 ("arm64: compile the kernel with ptrauth return address signing") ... but at the time we had no rationale for signing leaf functions. Subsequently, we considered avoiding signing leaf functions: https://lore.kernel.org/linux-arm-kernel/1586856741-26839-1-git-send-email-amit.kachhap@arm.com/ https://lore.kernel.org/linux-arm-kernel/1588149371-20310-1-git-send-email-amit.kachhap@arm.com/ ... however at the time we didn't have an abundance of reasons to avoid signing leaf functions as above (e.g. the BTI case), we had no hardware to make performance measurements, and it was reasoned that this gave some level of protection against a limited set of code-reuse gadgets which would fall through to a RET. We documented this in commit: 717b938 ("arm64: Document why we enable PAC support for leaf functions") Notably, this was before we supported any forward-edge CFI scheme (e.g. Arm BTI, or Clang CFI/kCFI), which would prevent jumping into the middle of a function. In addition, even with signing forced for leaf functions, AUTIASP may be placed before a number of instructions which might constitute such a gadget, e.g. | <user_regs_reset_single_step>: | f9400022 ldr x2, [x1] | d503233f paciasp | d50323bf autiasp | f9408401 ldr x1, [x0, #264] | 720b005f tst w2, #0x200000 | b26b0022 orr x2, x1, #0x200000 | 926af821 and x1, x1, #0xffffffffffdfffff | 9a820021 csel x1, x1, x2, eq // eq = none | f9008401 str x1, [x0, #264] | d65f03c0 ret | <fpsimd_cpu_dead>: | 2a0003e3 mov w3, w0 | 9000ff42 adrp x2, ffff800009ffd000 <xen_dynamic_chip+0x48> | 9120e042 add x2, x2, #0x838 | 52800000 mov w0, #0x0 // #0 | d503233f paciasp | f000d041 adrp x1, ffff800009a20000 <this_cpu_vector> | d50323bf autiasp | 9102c021 add x1, x1, #0xb0 | f8635842 ldr x2, [x2, w3, uxtw #3] | f821685f str xzr, [x2, x1] | d65f03c0 ret | d503201f nop So generally, trying to use AUTIASP to detect such gadgetization is not robust, and this is dealt with far better by forward-edge CFI (which is designed to prevent such cases). We should bite the bullet and stop pretending that AUTIASP is a mitigation for such forward-edge gadgetization. For the above reasons, this patch has the kernel consistently sign non-leaf functions and avoid signing leaf functions. Considering a defconfig v6.2-rc3 kernel built with LLVM 15.0.6: * The vmlinux is ~43KiB smaller: | [mark@lakrids:~/src/linux]% ls -al vmlinux-* | -rwxr-xr-x 1 mark mark 338547808 Jan 25 17:17 vmlinux-after | -rwxr-xr-x 1 mark mark 338591472 Jan 25 17:22 vmlinux-before * The resulting Image is 64KiB smaller: | [mark@lakrids:~/src/linux]% ls -al Image-* | -rwxr-xr-x 1 mark mark 32702976 Jan 25 17:17 Image-after | -rwxr-xr-x 1 mark mark 32768512 Jan 25 17:22 Image-before * There are ~400 fewer BTI gadgets: | [mark@lakrids:~/src/linux]% usekorg 12.1.0 aarch64-linux-objdump -d vmlinux-before 2> /dev/null | grep -ow 'paciasp\|bti\sc\?' | sort | uniq -c | 1219 bti c | 61982 paciasp | [mark@lakrids:~/src/linux]% usekorg 12.1.0 aarch64-linux-objdump -d vmlinux-after 2> /dev/null | grep -ow 'paciasp\|bti\sc\?' | sort | uniq -c | 10099 bti c | 52699 paciasp Which is +8880 BTIs, and -9283 PACIASPs, for -403 unnecessary BTI gadgets. While this is small relative to the total, distinguishing the two cases will make it easier to analyse and reduce this set further in future. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Mark Brown <broonie@kernel.org> Cc: Amit Daniel Kachhap <amit.kachhap@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20230131105809.991288-3-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> [resolved conflicts] Signed-off-by: Mahmoud Adam <mngyadam@amazon.com>
heynemax
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Jul 1, 2025
Commit c68cf52 upstream Currently, when CONFIG_ARM64_PTR_AUTH_KERNEL=y (and CONFIG_UNWIND_PATCH_PAC_INTO_SCS=n), we enable pointer authentication for all functions, including leaf functions. This isn't necessary, and is unfortunate for a few reasons: * Any PACIASP instruction is implicitly a `BTI C` landing pad, and forcing the addition of a PACIASP in every function introduces a larger set of BTI gadgets than is necessary. * The PACIASP and AUTIASP instructions make leaf functions larger than necessary, bloating the kernel Image. For a defconfig v6.2-rc3 kernel, this appears to add ~64KiB relative to not signing leaf functions, which is unfortunate but not entirely onerous. * The PACIASP and AUTIASP instructions potentially make leaf functions more expensive in terms of performance and/or power. For many trivial leaf functions, this is clearly unnecessary, e.g. | <arch_local_save_flags>: | d503233f paciasp | d53b4220 mrs x0, daif | d50323bf autiasp | d65f03c0 ret | <calibration_delay_done>: | d503233f paciasp | d50323bf autiasp | d65f03c0 ret | d503201f nop * When CONFIG_UNWIND_PATCH_PAC_INTO_SCS=y we disable pointer authentication for leaf functions, so clearly this is not functionally necessary, indicates we have an inconsistent threat model, and convolutes the Makefile logic. We've used pointer authentication in leaf functions since the introduction of in-kernel pointer authentication in commit: 74afda4 ("arm64: compile the kernel with ptrauth return address signing") ... but at the time we had no rationale for signing leaf functions. Subsequently, we considered avoiding signing leaf functions: https://lore.kernel.org/linux-arm-kernel/1586856741-26839-1-git-send-email-amit.kachhap@arm.com/ https://lore.kernel.org/linux-arm-kernel/1588149371-20310-1-git-send-email-amit.kachhap@arm.com/ ... however at the time we didn't have an abundance of reasons to avoid signing leaf functions as above (e.g. the BTI case), we had no hardware to make performance measurements, and it was reasoned that this gave some level of protection against a limited set of code-reuse gadgets which would fall through to a RET. We documented this in commit: 717b938 ("arm64: Document why we enable PAC support for leaf functions") Notably, this was before we supported any forward-edge CFI scheme (e.g. Arm BTI, or Clang CFI/kCFI), which would prevent jumping into the middle of a function. In addition, even with signing forced for leaf functions, AUTIASP may be placed before a number of instructions which might constitute such a gadget, e.g. | <user_regs_reset_single_step>: | f9400022 ldr x2, [x1] | d503233f paciasp | d50323bf autiasp | f9408401 ldr x1, [x0, #264] | 720b005f tst w2, #0x200000 | b26b0022 orr x2, x1, #0x200000 | 926af821 and x1, x1, #0xffffffffffdfffff | 9a820021 csel x1, x1, x2, eq // eq = none | f9008401 str x1, [x0, #264] | d65f03c0 ret | <fpsimd_cpu_dead>: | 2a0003e3 mov w3, w0 | 9000ff42 adrp x2, ffff800009ffd000 <xen_dynamic_chip+0x48> | 9120e042 add x2, x2, #0x838 | 52800000 mov w0, #0x0 // #0 | d503233f paciasp | f000d041 adrp x1, ffff800009a20000 <this_cpu_vector> | d50323bf autiasp | 9102c021 add x1, x1, #0xb0 | f8635842 ldr x2, [x2, w3, uxtw #3] | f821685f str xzr, [x2, x1] | d65f03c0 ret | d503201f nop So generally, trying to use AUTIASP to detect such gadgetization is not robust, and this is dealt with far better by forward-edge CFI (which is designed to prevent such cases). We should bite the bullet and stop pretending that AUTIASP is a mitigation for such forward-edge gadgetization. For the above reasons, this patch has the kernel consistently sign non-leaf functions and avoid signing leaf functions. Considering a defconfig v6.2-rc3 kernel built with LLVM 15.0.6: * The vmlinux is ~43KiB smaller: | [mark@lakrids:~/src/linux]% ls -al vmlinux-* | -rwxr-xr-x 1 mark mark 338547808 Jan 25 17:17 vmlinux-after | -rwxr-xr-x 1 mark mark 338591472 Jan 25 17:22 vmlinux-before * The resulting Image is 64KiB smaller: | [mark@lakrids:~/src/linux]% ls -al Image-* | -rwxr-xr-x 1 mark mark 32702976 Jan 25 17:17 Image-after | -rwxr-xr-x 1 mark mark 32768512 Jan 25 17:22 Image-before * There are ~400 fewer BTI gadgets: | [mark@lakrids:~/src/linux]% usekorg 12.1.0 aarch64-linux-objdump -d vmlinux-before 2> /dev/null | grep -ow 'paciasp\|bti\sc\?' | sort | uniq -c | 1219 bti c | 61982 paciasp | [mark@lakrids:~/src/linux]% usekorg 12.1.0 aarch64-linux-objdump -d vmlinux-after 2> /dev/null | grep -ow 'paciasp\|bti\sc\?' | sort | uniq -c | 10099 bti c | 52699 paciasp Which is +8880 BTIs, and -9283 PACIASPs, for -403 unnecessary BTI gadgets. While this is small relative to the total, distinguishing the two cases will make it easier to analyse and reduce this set further in future. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Mark Brown <broonie@kernel.org> Cc: Amit Daniel Kachhap <amit.kachhap@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20230131105809.991288-3-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> [resolved conflicts] Signed-off-by: Mahmoud Adam <mngyadam@amazon.com>
jaywang-amazon
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Commit c68cf52 upstream Currently, when CONFIG_ARM64_PTR_AUTH_KERNEL=y (and CONFIG_UNWIND_PATCH_PAC_INTO_SCS=n), we enable pointer authentication for all functions, including leaf functions. This isn't necessary, and is unfortunate for a few reasons: * Any PACIASP instruction is implicitly a `BTI C` landing pad, and forcing the addition of a PACIASP in every function introduces a larger set of BTI gadgets than is necessary. * The PACIASP and AUTIASP instructions make leaf functions larger than necessary, bloating the kernel Image. For a defconfig v6.2-rc3 kernel, this appears to add ~64KiB relative to not signing leaf functions, which is unfortunate but not entirely onerous. * The PACIASP and AUTIASP instructions potentially make leaf functions more expensive in terms of performance and/or power. For many trivial leaf functions, this is clearly unnecessary, e.g. | <arch_local_save_flags>: | d503233f paciasp | d53b4220 mrs x0, daif | d50323bf autiasp | d65f03c0 ret | <calibration_delay_done>: | d503233f paciasp | d50323bf autiasp | d65f03c0 ret | d503201f nop * When CONFIG_UNWIND_PATCH_PAC_INTO_SCS=y we disable pointer authentication for leaf functions, so clearly this is not functionally necessary, indicates we have an inconsistent threat model, and convolutes the Makefile logic. We've used pointer authentication in leaf functions since the introduction of in-kernel pointer authentication in commit: 74afda4 ("arm64: compile the kernel with ptrauth return address signing") ... but at the time we had no rationale for signing leaf functions. Subsequently, we considered avoiding signing leaf functions: https://lore.kernel.org/linux-arm-kernel/1586856741-26839-1-git-send-email-amit.kachhap@arm.com/ https://lore.kernel.org/linux-arm-kernel/1588149371-20310-1-git-send-email-amit.kachhap@arm.com/ ... however at the time we didn't have an abundance of reasons to avoid signing leaf functions as above (e.g. the BTI case), we had no hardware to make performance measurements, and it was reasoned that this gave some level of protection against a limited set of code-reuse gadgets which would fall through to a RET. We documented this in commit: 717b938 ("arm64: Document why we enable PAC support for leaf functions") Notably, this was before we supported any forward-edge CFI scheme (e.g. Arm BTI, or Clang CFI/kCFI), which would prevent jumping into the middle of a function. In addition, even with signing forced for leaf functions, AUTIASP may be placed before a number of instructions which might constitute such a gadget, e.g. | <user_regs_reset_single_step>: | f9400022 ldr x2, [x1] | d503233f paciasp | d50323bf autiasp | f9408401 ldr x1, [x0, #264] | 720b005f tst w2, #0x200000 | b26b0022 orr x2, x1, #0x200000 | 926af821 and x1, x1, #0xffffffffffdfffff | 9a820021 csel x1, x1, x2, eq // eq = none | f9008401 str x1, [x0, #264] | d65f03c0 ret | <fpsimd_cpu_dead>: | 2a0003e3 mov w3, w0 | 9000ff42 adrp x2, ffff800009ffd000 <xen_dynamic_chip+0x48> | 9120e042 add x2, x2, #0x838 | 52800000 mov w0, #0x0 // #0 | d503233f paciasp | f000d041 adrp x1, ffff800009a20000 <this_cpu_vector> | d50323bf autiasp | 9102c021 add x1, x1, #0xb0 | f8635842 ldr x2, [x2, w3, uxtw #3] | f821685f str xzr, [x2, x1] | d65f03c0 ret | d503201f nop So generally, trying to use AUTIASP to detect such gadgetization is not robust, and this is dealt with far better by forward-edge CFI (which is designed to prevent such cases). We should bite the bullet and stop pretending that AUTIASP is a mitigation for such forward-edge gadgetization. For the above reasons, this patch has the kernel consistently sign non-leaf functions and avoid signing leaf functions. Considering a defconfig v6.2-rc3 kernel built with LLVM 15.0.6: * The vmlinux is ~43KiB smaller: | [mark@lakrids:~/src/linux]% ls -al vmlinux-* | -rwxr-xr-x 1 mark mark 338547808 Jan 25 17:17 vmlinux-after | -rwxr-xr-x 1 mark mark 338591472 Jan 25 17:22 vmlinux-before * The resulting Image is 64KiB smaller: | [mark@lakrids:~/src/linux]% ls -al Image-* | -rwxr-xr-x 1 mark mark 32702976 Jan 25 17:17 Image-after | -rwxr-xr-x 1 mark mark 32768512 Jan 25 17:22 Image-before * There are ~400 fewer BTI gadgets: | [mark@lakrids:~/src/linux]% usekorg 12.1.0 aarch64-linux-objdump -d vmlinux-before 2> /dev/null | grep -ow 'paciasp\|bti\sc\?' | sort | uniq -c | 1219 bti c | 61982 paciasp | [mark@lakrids:~/src/linux]% usekorg 12.1.0 aarch64-linux-objdump -d vmlinux-after 2> /dev/null | grep -ow 'paciasp\|bti\sc\?' | sort | uniq -c | 10099 bti c | 52699 paciasp Which is +8880 BTIs, and -9283 PACIASPs, for -403 unnecessary BTI gadgets. While this is small relative to the total, distinguishing the two cases will make it easier to analyse and reduce this set further in future. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Mark Brown <broonie@kernel.org> Cc: Amit Daniel Kachhap <amit.kachhap@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20230131105809.991288-3-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> [resolved conflicts] Signed-off-by: Mahmoud Adam <mngyadam@amazon.com>
paniakin-aws
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Jul 1, 2025
Commit c68cf52 upstream Currently, when CONFIG_ARM64_PTR_AUTH_KERNEL=y (and CONFIG_UNWIND_PATCH_PAC_INTO_SCS=n), we enable pointer authentication for all functions, including leaf functions. This isn't necessary, and is unfortunate for a few reasons: * Any PACIASP instruction is implicitly a `BTI C` landing pad, and forcing the addition of a PACIASP in every function introduces a larger set of BTI gadgets than is necessary. * The PACIASP and AUTIASP instructions make leaf functions larger than necessary, bloating the kernel Image. For a defconfig v6.2-rc3 kernel, this appears to add ~64KiB relative to not signing leaf functions, which is unfortunate but not entirely onerous. * The PACIASP and AUTIASP instructions potentially make leaf functions more expensive in terms of performance and/or power. For many trivial leaf functions, this is clearly unnecessary, e.g. | <arch_local_save_flags>: | d503233f paciasp | d53b4220 mrs x0, daif | d50323bf autiasp | d65f03c0 ret | <calibration_delay_done>: | d503233f paciasp | d50323bf autiasp | d65f03c0 ret | d503201f nop * When CONFIG_UNWIND_PATCH_PAC_INTO_SCS=y we disable pointer authentication for leaf functions, so clearly this is not functionally necessary, indicates we have an inconsistent threat model, and convolutes the Makefile logic. We've used pointer authentication in leaf functions since the introduction of in-kernel pointer authentication in commit: 74afda4 ("arm64: compile the kernel with ptrauth return address signing") ... but at the time we had no rationale for signing leaf functions. Subsequently, we considered avoiding signing leaf functions: https://lore.kernel.org/linux-arm-kernel/1586856741-26839-1-git-send-email-amit.kachhap@arm.com/ https://lore.kernel.org/linux-arm-kernel/1588149371-20310-1-git-send-email-amit.kachhap@arm.com/ ... however at the time we didn't have an abundance of reasons to avoid signing leaf functions as above (e.g. the BTI case), we had no hardware to make performance measurements, and it was reasoned that this gave some level of protection against a limited set of code-reuse gadgets which would fall through to a RET. We documented this in commit: 717b938 ("arm64: Document why we enable PAC support for leaf functions") Notably, this was before we supported any forward-edge CFI scheme (e.g. Arm BTI, or Clang CFI/kCFI), which would prevent jumping into the middle of a function. In addition, even with signing forced for leaf functions, AUTIASP may be placed before a number of instructions which might constitute such a gadget, e.g. | <user_regs_reset_single_step>: | f9400022 ldr x2, [x1] | d503233f paciasp | d50323bf autiasp | f9408401 ldr x1, [x0, #264] | 720b005f tst w2, #0x200000 | b26b0022 orr x2, x1, #0x200000 | 926af821 and x1, x1, #0xffffffffffdfffff | 9a820021 csel x1, x1, x2, eq // eq = none | f9008401 str x1, [x0, #264] | d65f03c0 ret | <fpsimd_cpu_dead>: | 2a0003e3 mov w3, w0 | 9000ff42 adrp x2, ffff800009ffd000 <xen_dynamic_chip+0x48> | 9120e042 add x2, x2, #0x838 | 52800000 mov w0, #0x0 // #0 | d503233f paciasp | f000d041 adrp x1, ffff800009a20000 <this_cpu_vector> | d50323bf autiasp | 9102c021 add x1, x1, #0xb0 | f8635842 ldr x2, [x2, w3, uxtw #3] | f821685f str xzr, [x2, x1] | d65f03c0 ret | d503201f nop So generally, trying to use AUTIASP to detect such gadgetization is not robust, and this is dealt with far better by forward-edge CFI (which is designed to prevent such cases). We should bite the bullet and stop pretending that AUTIASP is a mitigation for such forward-edge gadgetization. For the above reasons, this patch has the kernel consistently sign non-leaf functions and avoid signing leaf functions. Considering a defconfig v6.2-rc3 kernel built with LLVM 15.0.6: * The vmlinux is ~43KiB smaller: | [mark@lakrids:~/src/linux]% ls -al vmlinux-* | -rwxr-xr-x 1 mark mark 338547808 Jan 25 17:17 vmlinux-after | -rwxr-xr-x 1 mark mark 338591472 Jan 25 17:22 vmlinux-before * The resulting Image is 64KiB smaller: | [mark@lakrids:~/src/linux]% ls -al Image-* | -rwxr-xr-x 1 mark mark 32702976 Jan 25 17:17 Image-after | -rwxr-xr-x 1 mark mark 32768512 Jan 25 17:22 Image-before * There are ~400 fewer BTI gadgets: | [mark@lakrids:~/src/linux]% usekorg 12.1.0 aarch64-linux-objdump -d vmlinux-before 2> /dev/null | grep -ow 'paciasp\|bti\sc\?' | sort | uniq -c | 1219 bti c | 61982 paciasp | [mark@lakrids:~/src/linux]% usekorg 12.1.0 aarch64-linux-objdump -d vmlinux-after 2> /dev/null | grep -ow 'paciasp\|bti\sc\?' | sort | uniq -c | 10099 bti c | 52699 paciasp Which is +8880 BTIs, and -9283 PACIASPs, for -403 unnecessary BTI gadgets. While this is small relative to the total, distinguishing the two cases will make it easier to analyse and reduce this set further in future. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Mark Brown <broonie@kernel.org> Cc: Amit Daniel Kachhap <amit.kachhap@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20230131105809.991288-3-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> [resolved conflicts] Signed-off-by: Mahmoud Adam <mngyadam@amazon.com>
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…ress Bug report and analysis from Ding Hui. During iSCSI session logout, if another task accesses the shost ipaddress attr, we can get a KASAN UAF report like this: [ 276.942144] BUG: KASAN: use-after-free in _raw_spin_lock_bh+0x78/0xe0 [ 276.942535] Write of size 4 at addr ffff8881053b45b8 by task cat/4088 [ 276.943511] CPU: 2 PID: 4088 Comm: cat Tainted: G E 6.1.0-rc8+ #3 [ 276.943997] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020 [ 276.944470] Call Trace: [ 276.944943] <TASK> [ 276.945397] dump_stack_lvl+0x34/0x48 [ 276.945887] print_address_description.constprop.0+0x86/0x1e7 [ 276.946421] print_report+0x36/0x4f [ 276.947358] kasan_report+0xad/0x130 [ 276.948234] kasan_check_range+0x35/0x1c0 [ 276.948674] _raw_spin_lock_bh+0x78/0xe0 [ 276.949989] iscsi_sw_tcp_host_get_param+0xad/0x2e0 [iscsi_tcp] [ 276.951765] show_host_param_ISCSI_HOST_PARAM_IPADDRESS+0xe9/0x130 [scsi_transport_iscsi] [ 276.952185] dev_attr_show+0x3f/0x80 [ 276.953005] sysfs_kf_seq_show+0x1fb/0x3e0 [ 276.953401] seq_read_iter+0x402/0x1020 [ 276.954260] vfs_read+0x532/0x7b0 [ 276.955113] ksys_read+0xed/0x1c0 [ 276.955952] do_syscall_64+0x38/0x90 [ 276.956347] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 276.956769] RIP: 0033:0x7f5d3a679222 [ 276.957161] Code: c0 e9 b2 fe ff ff 50 48 8d 3d 32 c0 0b 00 e8 a5 fe 01 00 0f 1f 44 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 0f 05 <48> 3d 00 f0 ff ff 77 56 c3 0f 1f 44 00 00 48 83 ec 28 48 89 54 24 [ 276.958009] RSP: 002b:00007ffc864d16a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 276.958431] RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f5d3a679222 [ 276.958857] RDX: 0000000000020000 RSI: 00007f5d3a4fe000 RDI: 0000000000000003 [ 276.959281] RBP: 00007f5d3a4fe000 R08: 00000000ffffffff R09: 0000000000000000 [ 276.959682] R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000020000 [ 276.960126] R13: 0000000000000003 R14: 0000000000000000 R15: 0000557a26dada58 [ 276.960536] </TASK> [ 276.961357] Allocated by task 2209: [ 276.961756] kasan_save_stack+0x1e/0x40 [ 276.962170] kasan_set_track+0x21/0x30 [ 276.962557] __kasan_kmalloc+0x7e/0x90 [ 276.962923] __kmalloc+0x5b/0x140 [ 276.963308] iscsi_alloc_session+0x28/0x840 [scsi_transport_iscsi] [ 276.963712] iscsi_session_setup+0xda/0xba0 [libiscsi] [ 276.964078] iscsi_sw_tcp_session_create+0x1fd/0x330 [iscsi_tcp] [ 276.964431] iscsi_if_create_session.isra.0+0x50/0x260 [scsi_transport_iscsi] [ 276.964793] iscsi_if_recv_msg+0xc5a/0x2660 [scsi_transport_iscsi] [ 276.965153] iscsi_if_rx+0x198/0x4b0 [scsi_transport_iscsi] [ 276.965546] netlink_unicast+0x4d5/0x7b0 [ 276.965905] netlink_sendmsg+0x78d/0xc30 [ 276.966236] sock_sendmsg+0xe5/0x120 [ 276.966576] ____sys_sendmsg+0x5fe/0x860 [ 276.966923] ___sys_sendmsg+0xe0/0x170 [ 276.967300] __sys_sendmsg+0xc8/0x170 [ 276.967666] do_syscall_64+0x38/0x90 [ 276.968028] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 276.968773] Freed by task 2209: [ 276.969111] kasan_save_stack+0x1e/0x40 [ 276.969449] kasan_set_track+0x21/0x30 [ 276.969789] kasan_save_free_info+0x2a/0x50 [ 276.970146] __kasan_slab_free+0x106/0x190 [ 276.970470] __kmem_cache_free+0x133/0x270 [ 276.970816] device_release+0x98/0x210 [ 276.971145] kobject_cleanup+0x101/0x360 [ 276.971462] iscsi_session_teardown+0x3fb/0x530 [libiscsi] [ 276.971775] iscsi_sw_tcp_session_destroy+0xd8/0x130 [iscsi_tcp] [ 276.972143] iscsi_if_recv_msg+0x1bf1/0x2660 [scsi_transport_iscsi] [ 276.972485] iscsi_if_rx+0x198/0x4b0 [scsi_transport_iscsi] [ 276.972808] netlink_unicast+0x4d5/0x7b0 [ 276.973201] netlink_sendmsg+0x78d/0xc30 [ 276.973544] sock_sendmsg+0xe5/0x120 [ 276.973864] ____sys_sendmsg+0x5fe/0x860 [ 276.974248] ___sys_sendmsg+0xe0/0x170 [ 276.974583] __sys_sendmsg+0xc8/0x170 [ 276.974891] do_syscall_64+0x38/0x90 [ 276.975216] entry_SYSCALL_64_after_hwframe+0x63/0xcd We can easily reproduce by two tasks: 1. while :; do iscsiadm -m node --login; iscsiadm -m node --logout; done 2. while :; do cat \ /sys/devices/platform/host*/iscsi_host/host*/ipaddress; done iscsid | cat --------------------------------+--------------------------------------- |- iscsi_sw_tcp_session_destroy | |- iscsi_session_teardown | |- device_release | |- iscsi_session_release ||- dev_attr_show |- kfree | |- show_host_param_ | ISCSI_HOST_PARAM_IPADDRESS | |- iscsi_sw_tcp_host_get_param | |- r/w tcp_sw_host->session (UAF) |- iscsi_host_remove | |- iscsi_host_free | Fix the above bug by splitting the session removal into 2 parts: 1. removal from iSCSI class which includes sysfs and removal from host tracking. 2. freeing of session. During iscsi_tcp host and session removal we can remove the session from sysfs then remove the host from sysfs. At this point we know userspace is not accessing the kernel via sysfs so we can free the session and host. Link: https://lore.kernel.org/r/20230117193937.21244-2-michael.christie@oracle.com Signed-off-by: Mike Christie <michael.christie@oracle.com> Reviewed-by: Lee Duncan <lduncan@suse.com> Acked-by: Ding Hui <dinghui@sangfor.com.cn> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> (cherry picked from commit 6f1d64b) [Fixed to apply on 5.10] Signed-off-by: Puranjay Mohan <pjy@amazon.com>
paniakin-aws
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Commit c68cf52 upstream Currently, when CONFIG_ARM64_PTR_AUTH_KERNEL=y (and CONFIG_UNWIND_PATCH_PAC_INTO_SCS=n), we enable pointer authentication for all functions, including leaf functions. This isn't necessary, and is unfortunate for a few reasons: * Any PACIASP instruction is implicitly a `BTI C` landing pad, and forcing the addition of a PACIASP in every function introduces a larger set of BTI gadgets than is necessary. * The PACIASP and AUTIASP instructions make leaf functions larger than necessary, bloating the kernel Image. For a defconfig v6.2-rc3 kernel, this appears to add ~64KiB relative to not signing leaf functions, which is unfortunate but not entirely onerous. * The PACIASP and AUTIASP instructions potentially make leaf functions more expensive in terms of performance and/or power. For many trivial leaf functions, this is clearly unnecessary, e.g. | <arch_local_save_flags>: | d503233f paciasp | d53b4220 mrs x0, daif | d50323bf autiasp | d65f03c0 ret | <calibration_delay_done>: | d503233f paciasp | d50323bf autiasp | d65f03c0 ret | d503201f nop * When CONFIG_UNWIND_PATCH_PAC_INTO_SCS=y we disable pointer authentication for leaf functions, so clearly this is not functionally necessary, indicates we have an inconsistent threat model, and convolutes the Makefile logic. We've used pointer authentication in leaf functions since the introduction of in-kernel pointer authentication in commit: 74afda4 ("arm64: compile the kernel with ptrauth return address signing") ... but at the time we had no rationale for signing leaf functions. Subsequently, we considered avoiding signing leaf functions: https://lore.kernel.org/linux-arm-kernel/1586856741-26839-1-git-send-email-amit.kachhap@arm.com/ https://lore.kernel.org/linux-arm-kernel/1588149371-20310-1-git-send-email-amit.kachhap@arm.com/ ... however at the time we didn't have an abundance of reasons to avoid signing leaf functions as above (e.g. the BTI case), we had no hardware to make performance measurements, and it was reasoned that this gave some level of protection against a limited set of code-reuse gadgets which would fall through to a RET. We documented this in commit: 717b938 ("arm64: Document why we enable PAC support for leaf functions") Notably, this was before we supported any forward-edge CFI scheme (e.g. Arm BTI, or Clang CFI/kCFI), which would prevent jumping into the middle of a function. In addition, even with signing forced for leaf functions, AUTIASP may be placed before a number of instructions which might constitute such a gadget, e.g. | <user_regs_reset_single_step>: | f9400022 ldr x2, [x1] | d503233f paciasp | d50323bf autiasp | f9408401 ldr x1, [x0, #264] | 720b005f tst w2, #0x200000 | b26b0022 orr x2, x1, #0x200000 | 926af821 and x1, x1, #0xffffffffffdfffff | 9a820021 csel x1, x1, x2, eq // eq = none | f9008401 str x1, [x0, #264] | d65f03c0 ret | <fpsimd_cpu_dead>: | 2a0003e3 mov w3, w0 | 9000ff42 adrp x2, ffff800009ffd000 <xen_dynamic_chip+0x48> | 9120e042 add x2, x2, #0x838 | 52800000 mov w0, #0x0 // #0 | d503233f paciasp | f000d041 adrp x1, ffff800009a20000 <this_cpu_vector> | d50323bf autiasp | 9102c021 add x1, x1, #0xb0 | f8635842 ldr x2, [x2, w3, uxtw #3] | f821685f str xzr, [x2, x1] | d65f03c0 ret | d503201f nop So generally, trying to use AUTIASP to detect such gadgetization is not robust, and this is dealt with far better by forward-edge CFI (which is designed to prevent such cases). We should bite the bullet and stop pretending that AUTIASP is a mitigation for such forward-edge gadgetization. For the above reasons, this patch has the kernel consistently sign non-leaf functions and avoid signing leaf functions. Considering a defconfig v6.2-rc3 kernel built with LLVM 15.0.6: * The vmlinux is ~43KiB smaller: | [mark@lakrids:~/src/linux]% ls -al vmlinux-* | -rwxr-xr-x 1 mark mark 338547808 Jan 25 17:17 vmlinux-after | -rwxr-xr-x 1 mark mark 338591472 Jan 25 17:22 vmlinux-before * The resulting Image is 64KiB smaller: | [mark@lakrids:~/src/linux]% ls -al Image-* | -rwxr-xr-x 1 mark mark 32702976 Jan 25 17:17 Image-after | -rwxr-xr-x 1 mark mark 32768512 Jan 25 17:22 Image-before * There are ~400 fewer BTI gadgets: | [mark@lakrids:~/src/linux]% usekorg 12.1.0 aarch64-linux-objdump -d vmlinux-before 2> /dev/null | grep -ow 'paciasp\|bti\sc\?' | sort | uniq -c | 1219 bti c | 61982 paciasp | [mark@lakrids:~/src/linux]% usekorg 12.1.0 aarch64-linux-objdump -d vmlinux-after 2> /dev/null | grep -ow 'paciasp\|bti\sc\?' | sort | uniq -c | 10099 bti c | 52699 paciasp Which is +8880 BTIs, and -9283 PACIASPs, for -403 unnecessary BTI gadgets. While this is small relative to the total, distinguishing the two cases will make it easier to analyse and reduce this set further in future. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Mark Brown <broonie@kernel.org> Cc: Amit Daniel Kachhap <amit.kachhap@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20230131105809.991288-3-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> [resolved conflicts] Signed-off-by: Mahmoud Adam <mngyadam@amazon.com>
paniakin-aws
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Jul 1, 2025
…ress Bug report and analysis from Ding Hui. During iSCSI session logout, if another task accesses the shost ipaddress attr, we can get a KASAN UAF report like this: [ 276.942144] BUG: KASAN: use-after-free in _raw_spin_lock_bh+0x78/0xe0 [ 276.942535] Write of size 4 at addr ffff8881053b45b8 by task cat/4088 [ 276.943511] CPU: 2 PID: 4088 Comm: cat Tainted: G E 6.1.0-rc8+ #3 [ 276.943997] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020 [ 276.944470] Call Trace: [ 276.944943] <TASK> [ 276.945397] dump_stack_lvl+0x34/0x48 [ 276.945887] print_address_description.constprop.0+0x86/0x1e7 [ 276.946421] print_report+0x36/0x4f [ 276.947358] kasan_report+0xad/0x130 [ 276.948234] kasan_check_range+0x35/0x1c0 [ 276.948674] _raw_spin_lock_bh+0x78/0xe0 [ 276.949989] iscsi_sw_tcp_host_get_param+0xad/0x2e0 [iscsi_tcp] [ 276.951765] show_host_param_ISCSI_HOST_PARAM_IPADDRESS+0xe9/0x130 [scsi_transport_iscsi] [ 276.952185] dev_attr_show+0x3f/0x80 [ 276.953005] sysfs_kf_seq_show+0x1fb/0x3e0 [ 276.953401] seq_read_iter+0x402/0x1020 [ 276.954260] vfs_read+0x532/0x7b0 [ 276.955113] ksys_read+0xed/0x1c0 [ 276.955952] do_syscall_64+0x38/0x90 [ 276.956347] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 276.956769] RIP: 0033:0x7f5d3a679222 [ 276.957161] Code: c0 e9 b2 fe ff ff 50 48 8d 3d 32 c0 0b 00 e8 a5 fe 01 00 0f 1f 44 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 0f 05 <48> 3d 00 f0 ff ff 77 56 c3 0f 1f 44 00 00 48 83 ec 28 48 89 54 24 [ 276.958009] RSP: 002b:00007ffc864d16a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 [ 276.958431] RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f5d3a679222 [ 276.958857] RDX: 0000000000020000 RSI: 00007f5d3a4fe000 RDI: 0000000000000003 [ 276.959281] RBP: 00007f5d3a4fe000 R08: 00000000ffffffff R09: 0000000000000000 [ 276.959682] R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000020000 [ 276.960126] R13: 0000000000000003 R14: 0000000000000000 R15: 0000557a26dada58 [ 276.960536] </TASK> [ 276.961357] Allocated by task 2209: [ 276.961756] kasan_save_stack+0x1e/0x40 [ 276.962170] kasan_set_track+0x21/0x30 [ 276.962557] __kasan_kmalloc+0x7e/0x90 [ 276.962923] __kmalloc+0x5b/0x140 [ 276.963308] iscsi_alloc_session+0x28/0x840 [scsi_transport_iscsi] [ 276.963712] iscsi_session_setup+0xda/0xba0 [libiscsi] [ 276.964078] iscsi_sw_tcp_session_create+0x1fd/0x330 [iscsi_tcp] [ 276.964431] iscsi_if_create_session.isra.0+0x50/0x260 [scsi_transport_iscsi] [ 276.964793] iscsi_if_recv_msg+0xc5a/0x2660 [scsi_transport_iscsi] [ 276.965153] iscsi_if_rx+0x198/0x4b0 [scsi_transport_iscsi] [ 276.965546] netlink_unicast+0x4d5/0x7b0 [ 276.965905] netlink_sendmsg+0x78d/0xc30 [ 276.966236] sock_sendmsg+0xe5/0x120 [ 276.966576] ____sys_sendmsg+0x5fe/0x860 [ 276.966923] ___sys_sendmsg+0xe0/0x170 [ 276.967300] __sys_sendmsg+0xc8/0x170 [ 276.967666] do_syscall_64+0x38/0x90 [ 276.968028] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 276.968773] Freed by task 2209: [ 276.969111] kasan_save_stack+0x1e/0x40 [ 276.969449] kasan_set_track+0x21/0x30 [ 276.969789] kasan_save_free_info+0x2a/0x50 [ 276.970146] __kasan_slab_free+0x106/0x190 [ 276.970470] __kmem_cache_free+0x133/0x270 [ 276.970816] device_release+0x98/0x210 [ 276.971145] kobject_cleanup+0x101/0x360 [ 276.971462] iscsi_session_teardown+0x3fb/0x530 [libiscsi] [ 276.971775] iscsi_sw_tcp_session_destroy+0xd8/0x130 [iscsi_tcp] [ 276.972143] iscsi_if_recv_msg+0x1bf1/0x2660 [scsi_transport_iscsi] [ 276.972485] iscsi_if_rx+0x198/0x4b0 [scsi_transport_iscsi] [ 276.972808] netlink_unicast+0x4d5/0x7b0 [ 276.973201] netlink_sendmsg+0x78d/0xc30 [ 276.973544] sock_sendmsg+0xe5/0x120 [ 276.973864] ____sys_sendmsg+0x5fe/0x860 [ 276.974248] ___sys_sendmsg+0xe0/0x170 [ 276.974583] __sys_sendmsg+0xc8/0x170 [ 276.974891] do_syscall_64+0x38/0x90 [ 276.975216] entry_SYSCALL_64_after_hwframe+0x63/0xcd We can easily reproduce by two tasks: 1. while :; do iscsiadm -m node --login; iscsiadm -m node --logout; done 2. while :; do cat \ /sys/devices/platform/host*/iscsi_host/host*/ipaddress; done iscsid | cat --------------------------------+--------------------------------------- |- iscsi_sw_tcp_session_destroy | |- iscsi_session_teardown | |- device_release | |- iscsi_session_release ||- dev_attr_show |- kfree | |- show_host_param_ | ISCSI_HOST_PARAM_IPADDRESS | |- iscsi_sw_tcp_host_get_param | |- r/w tcp_sw_host->session (UAF) |- iscsi_host_remove | |- iscsi_host_free | Fix the above bug by splitting the session removal into 2 parts: 1. removal from iSCSI class which includes sysfs and removal from host tracking. 2. freeing of session. During iscsi_tcp host and session removal we can remove the session from sysfs then remove the host from sysfs. At this point we know userspace is not accessing the kernel via sysfs so we can free the session and host. Link: https://lore.kernel.org/r/20230117193937.21244-2-michael.christie@oracle.com Signed-off-by: Mike Christie <michael.christie@oracle.com> Reviewed-by: Lee Duncan <lduncan@suse.com> Acked-by: Ding Hui <dinghui@sangfor.com.cn> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> (cherry picked from commit 6f1d64b) [Fixed to apply on 5.10] Signed-off-by: Puranjay Mohan <pjy@amazon.com>
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Bumps urllib3 from 2.0.4 to 2.0.7.
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Release 2.0.74e50fbc
Merge pull request from GHSA-g4mx-q9vg-27p480808b0
Fix docs build on Python 3.12 (#3144)f28deff
Add 1.26.17 to the current changelog262e3e3
Release 2.0.6644124e
Merge pull request from GHSA-v845-jxx5-vc9f740380c
Bump cryptography from 41.0.3 to 41.0.4 (#3131)d9f85a7
Release 2.0.5d41f412
Undeprecate pyOpenSSL module (#3127)b6c04cb
Fix a link to "absolute URI" definition (#3128)Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting
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