Amazon 5.10.y/btrfs soft lockup #2
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The huge_ptep_set_access_flags() can not make the huge pte old according to the discussion [1], that means we will always mornitor the young state of the hugetlb though we stopped accessing the hugetlb, as a result DAMON will get inaccurate accessing statistics. So changing to use set_huge_pte_at() to make the huge pte old to fix this issue. [1] https://lore.kernel.org/all/Yqy97gXI4Nqb7dYo@arm.com/ Link: https://lkml.kernel.org/r/1655692482-28797-1-git-send-email-baolin.wang@linux.alibaba.com Fixes: 49f4203 ("mm/damon: add access checking for hugetlb pages") Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: SeongJae Park <sj@kernel.org> Acked-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
damon_reclaim_init() allocates a memory chunk for ctx with damon_new_ctx(). When damon_select_ops() fails, ctx is not released, which will lead to a memory leak. We should release the ctx with damon_destroy_ctx() when damon_select_ops() fails to fix the memory leak. Link: https://lkml.kernel.org/r/20220714063746.2343549-1-niejianglei2021@163.com Fixes: 4d69c34 ("mm/damon/reclaim: use damon_select_ops() instead of damon_{v,p}a_set_operations()") Signed-off-by: Jianglei Nie <niejianglei2021@163.com> Reviewed-by: SeongJae Park <sj@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When user tries to create a DAMON context via the DAMON debugfs interface
with a name of an already existing context, the context directory creation
fails but a new context is created and added in the internal data
structure, due to absence of the directory creation success check. As a
result, memory could leak and DAMON cannot be turned on. An example test
case is as below:
# cd /sys/kernel/debug/damon/
# echo "off" > monitor_on
# echo paddr > target_ids
# echo "abc" > mk_context
# echo "abc" > mk_context
# echo $$ > abc/target_ids
# echo "on" > monitor_on <<< fails
Return value of 'debugfs_create_dir()' is expected to be ignored in
general, but this is an exceptional case as DAMON feature is depending
on the debugfs functionality and it has the potential duplicate name
issue. This commit therefore fixes the issue by checking the directory
creation failure and immediately return the error in the case.
Link: https://lkml.kernel.org/r/20220821180853.2400-1-sj@kernel.org
Fixes: 75c1c2b ("mm/damon/dbgfs: support multiple contexts")
Signed-off-by: Badari Pulavarty <badari.pulavarty@intel.com>
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org> [ 5.15.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This reverts commit 509c2c9. Commit "1a072f13b2dc Mitigate unbalanced RETs on vmexit via serialising wrmsr" addresses this with less performance impact. [ Hailmo: Resolved conflicts when rebasing onto 5.10.190 and adding SRSO and GDS support ] Signed-off-by: Suraj Jitindar Singh <surajjs@amazon.com>
…-rwx-segments" This reverts commit 8f4f2c9. This causes arm64 debug builds to fail with: *** ERROR: No build ID note found in /builddir/build/BUILDROOT/kernel-5.15.63-32.131.amzn2.aarch64/usr/lib/debug/lib/modules/5.15.63-32.131.amzn2.aarch64/vmlinux This is due to the notes section which contains the build id being missing from the linux elf. Revert this commit until this can be remedied. Signed-off-by: Suraj Jitindar Singh <surajjs@amazon.com>
Source: https://github.com/amzn/amzn-drivers/ Change Log: ## r2.8.0 release notes **Notes** * The driver is now dependent on the ptp module for loading See README for more details. **New Features** * Add support for PTP HW clock * Add support for SRD metrics Feature's enablement and documentation would be in future release **Bug Fixes** * Fix potential sign extension issue * Reduce memory footprint of some structs * Fix updating rx_copybreak issue * Fix xdp drops handling due to multibuf packets * Handle ena_calc_io_queue_size() possible errors * Destroy correct amount of xdp queues upon failure **Minor Changes** * Remove wide LLQ comment on supported versions * Backport uapi/bpf.h inclusion * Add a counter for driver's reset failures * Take xdp packets stats into account in ena_get_stats64() * Make queue stats code cleaner by removing if block * Remove redundant empty line * Remove confusing comment * Remove flag reading code duplication * Replace ENA local ENA_NAPI_BUDGET to global NAPI_POLL_WEIGHT * Change default print level for netif_ prints * Relocate skb_tx_timestamp() to improve time stamping accuracy * Backport bpf_warn_invalid_xdp_action() change * Fix incorrect indentation using spaces * Driver now compiles with Linux kernel 5.19 Signed-off-by: Suraj Jitindar Singh <surajjs@amazon.com>
Signed-off-by: Shaoying Xu <shaoyi@amazon.com>
When calling debugfs_lookup() the result must have dput() called on it, otherwise the memory will leak over time. Fix this up by properly calling dput(). Link: https://lkml.kernel.org/r/20220902191149.112434-1-sj@kernel.org Fixes: 75c1c2b ("mm/damon/dbgfs: support multiple contexts") Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: SeongJae Park <sj@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When damon_sysfs_add_target couldn't find proper task, New allocated damon_target structure isn't registered yet, So, it's impossible to free new allocated one by damon_sysfs_destroy_targets. By calling damon_add_target as soon as allocating new target, Fix this possible memory leak. Link: https://lkml.kernel.org/r/20220926160611.48536-1-sj@kernel.org Fixes: a61ea56 ("mm/damon/sysfs: link DAMON for virtual address spaces monitoring") Signed-off-by: Levi Yun <ppbuk5246@gmail.com> Signed-off-by: SeongJae Park <sj@kernel.org> Reviewed-by: SeongJae Park <sj@kernel.org> Cc: <stable@vger.kernel.org> [5.17.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: SeongJae Park <sjpark@amazon.com>
commit 9e7a4d9 upstream. Usage of spin locks was not allowed for tracing programs due to insufficient preemption checks. The verifier does not currently prevent LSM programs from using spin locks, but the helpers are not exposed via bpf_lsm_func_proto. Based on the discussion in [1], non-sleepable LSM programs should be able to use bpf_spin_{lock, unlock}. Sleepable LSM programs can be preempted which means that allowng spin locks will need more work (disabling preemption and the verifier ensuring that no sleepable helpers are called when a spin lock is held). [1]: https://lore.kernel.org/bpf/20201103153132.2717326-1-kpsingh@chromium.org/T/#md601a053229287659071600d3483523f752cd2fb Signed-off-by: KP Singh <kpsingh@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20201106103747.2780972-2-kpsingh@chromium.org Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
commit 4cf1bc1 upstream. Similar to bpf_local_storage for sockets and inodes add local storage for task_struct. The life-cycle of storage is managed with the life-cycle of the task_struct. i.e. the storage is destroyed along with the owning task with a callback to the bpf_task_storage_free from the task_free LSM hook. The BPF LSM allocates an __rcu pointer to the bpf_local_storage in the security blob which are now stackable and can co-exist with other LSMs. The userspace map operations can be done by using a pid fd as a key passed to the lookup, update and delete operations. Signed-off-by: KP Singh <kpsingh@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20201106103747.2780972-3-kpsingh@chromium.org Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Instead of putting io_uring's registered files in unix_gc() we want it to be done by io_uring itself. The trick here is to consider io_uring registered files for cycle detection but not actually putting them down. Because io_uring can't register other ring instances, this will remove all refs to the ring file triggering the ->release path and clean up with io_ring_ctx_free(). Cc: stable@vger.kernel.org Fixes: 6b06314 ("io_uring: add file set registration") Reported-and-tested-by: David Bouman <dbouman03@gmail.com> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> [axboe: add kerneldoc comment to skb, fold in skb leak fix] Signed-off-by: Jens Axboe <axboe@kernel.dk>
Since commit 0f91d13 ("mm/damon: simplify stop mechanism") delete kdamond_stop and change to use kthread stop mechanism, these obsolete comments should be removed accordingly. Link: https://lkml.kernel.org/r/20220531020421.46849-1-zhouchengming@bytedance.com Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Reviewed-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The kernel is in lockdown mode when secureboot is enabled and hence debugfs cannot be used. Add support for this and other general cases where debugfs cannot be read and communicate the same to the user before running tests. Signed-off-by: Gautam <gautammenghani201@gmail.com> Reviewed-by: SeongJae Park <sj@kernel.org> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
… due to online tuning support Patch series "mm/damon: trivial cleanups". This patchset contains trivial cleansups for DAMON code. This patch (of 6): Commit 81a8418 ("Docs/admin-guide/mm/damon/reclaim: document 'commit_inputs' parameter") has documented the 'commit_inputs' parameter which allows online parameter update, but it didn't remove a paragraph saying the online parameter update is impossible. This commit removes the obsolete paragraph. Link: https://lkml.kernel.org/r/20220606182310.48781-1-sj@kernel.org Link: https://lkml.kernel.org/r/20220606182310.48781-2-sj@kernel.org Fixes: 81a8418 ("Docs/admin-guide/mm/damon/reclaim: document 'commit_inputs' parameter") Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The function for knowing if given monitoring context's targets will have pid or not is defined and used in dbgfs only. However, the logic is also needed for sysfs. This commit moves the code to damon.h and makes both dbgfs and sysfs to use it. Link: https://lkml.kernel.org/r/20220606182310.48781-3-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
DAMON_RECLAIM's handling of 'commit_inputs' parameter is duplicated in 'after_aggregation()' and 'after_wmarks_check()' callbacks. This commit deduplicates the code for better maintenance. Link: https://lkml.kernel.org/r/20220606182310.48781-4-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
DAMON sysfs interface's DAMON context building and its online parameter update have duplicated code. This commit removes the duplicate. Link: https://lkml.kernel.org/r/20220606182310.48781-5-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
DAMON_RECLAIM's 'enabled' parameter store callback ('enabled_store()')
schedules the parameter check timer ('damon_reclaim_timer') if the
parameter is set as 'Y'. Then, the timer schedules itself to check if
user has set the parameter as 'N'. It's unnecessarily complex.
This commit makes it simpler by making the parameter store callback to
schedule the timer regardless of the parameter value and disabling the
timer's self scheduling.
Link: https://lkml.kernel.org/r/20220606182310.48781-6-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit adds 'damon_reclaim_' prefix to 'enabled_store()', so that we can distinguish it easily from the stack trace using 'faddr2line.sh' like tools. Link: https://lkml.kernel.org/r/20220606182310.48781-7-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
…and 'damos_action' values Patch series "Extend DAMOS for Proactive LRU-lists Sorting". Introduction ============ In short, this patchset 1) extends DAMON-based Operation Schemes (DAMOS) for low overhead data access pattern based LRU-lists sorting, and 2) implements a static kernel module for easy use of conservatively-tuned version of that using the extended DAMOS capability. Background ---------- As page-granularity access checking overhead could be significant on huge systems, LRU lists are normally not proactively sorted but partially and reactively sorted for special events including specific user requests, system calls and memory pressure. As a result, LRU lists are sometimes not so perfectly prepared to be used as a trustworthy access pattern source for some situations including reclamation target pages selection under sudden memory pressure. DAMON-based Proactive LRU-lists Sorting --------------------------------------- Because DAMON can identify access patterns of best-effort accuracy while inducing only user-specified range of overhead, using DAMON for Proactive LRU-lists Sorting (PLRUS) could be helpful for this situation. The idea is quite simple. Find hot pages and cold pages using DAMON, and prioritize hot pages while deprioritizing cold pages on their LRU-lists. This patchset extends DAMON to support such schemes by introducing a couple of new DAMOS actions for prioritizing and deprioritizing memory regions of specific access patterns on their LRU-lists. In detail, this patchset simply uses 'mark_page_accessed()' and 'deactivate_page()' functions for prioritization and deprioritization of pages on their LRU lists, respectively. To make the scheme easy to use without complex tuning for common situations, this patchset further implements a static kernel module called 'DAMON_LRU_SORT' using the extended DAMOS functionality. It proactively sorts LRU-lists using DAMON with conservatively chosen default hotness/coldness thresholds and small CPU usage quota limit. That is, the module under its default parameters will make no harm for common situation but provide some level of benefit for systems having clear hot/cold access pattern under only memory pressure while consuming only limited small portion of CPU time. Related Works ------------- Proactive reclamation is well known to be helpful for reducing non-optimal reclamation target selection caused performance drops. However, proactive reclamation is not a best option for some cases, because it could incur additional I/O. For an example, it could be prohitive for systems using storage devices that total number of writes is limited, or cloud block storages that charges every I/O. Some proactive reclamation approaches[1,2] induce a level of memory pressure using memcg files or swappiness while monitoring PSI. As reclamation target selection is still relying on the original LRU-lists mechanism, using DAMON-based proactive reclamation before inducing the proactive reclamation could allow more memory saving with same level of performance overhead, or less performance overhead with same level of memory saving. [1] https://blogs.oracle.com/linux/post/anticipating-your-memory-needs [2] https://www.pdl.cmu.edu/ftp/NVM/tmo_asplos22.pdf Evaluation ========== In short, PLRUS achieves 10% memory PSI (some) reduction, 14% major page faults reduction, and 3.74% speedup under memory pressure. Setup ----- To show the effect of PLRUS, I run PARSEC3 and SPLASH-2X benchmarks under below variant systems and measure a few metrics including the runtime of each workload, number of system-wide major page faults, and system-wide memory PSI (some). - orig: v5.18-rc4 based mm-unstable kernel + this patchset, but no DAMON scheme applied. - mprs: Same to 'orig' but artificial memory pressure is induced. - plrus: Same to 'mprs' but a radically tuned PLRUS scheme is applied to the entire physical address space of the system. For the artificial memory pressure, I set 'memory.limit_in_bytes' to 75% of the running workload's peak RSS, wait 1 second, remove the pressure by setting it to 200% of the peak RSS, wait 10 seconds, and repeat the procedure until the workload finishes[1]. I use zram based swap device. The tests are automated[2]. [1] https://github.com/awslabs/damon-tests/blob/next/perf/runners/back/0009_memcg_pressure.sh [2] https://github.com/awslabs/damon-tests/blob/next/perf/full_once_config.sh Radically Tuned PLRUS --------------------- To show effect of PLRUS on the PARSEC3/SPLASH-2X workloads which runs for no long time, we use radically tuned version of PLRUS. The version asks DAMON to do the proactive LRU-lists sorting as below. 1. Find any memory regions shown some accesses (approximately >=20 accesses per 100 sampling) and prioritize pages of the regions on their LRU lists using up to 2% CPU time. Under the CPU time limit, prioritize regions having higher access frequency and kept the access frequency longer first. 2. Find any memory regions shown no access for at least >=5 seconds and deprioritize pages of the rgions on their LRU lists using up to 2% CPU time. Under the CPU time limit, deprioritize regions that not accessed for longer time first. Results ------- I repeat the tests 25 times and calculate average of the measured numbers. The results are as below: metric orig mprs plrus plrus/mprs runtime_seconds 190.06 292.83 281.87 0.96 pgmajfaults 852.55 8769420.00 7525040.00 0.86 memory_psi_some_us 106911.00 6943420.00 6220920.00 0.90 The first row is for legend. The first cell shows the metric that the following cells of the row shows. Second, third, and fourth cells show the metrics under the configs shown at the first row of the cell, and the fifth cell shows the metric under 'plrus' divided by the metric under 'mprs'. Second row shows the averaged runtime of the workloads in seconds. Third row shows the number of system-wide major page faults while the test was ongoing. Fourth row shows the system-wide memory pressure stall for some processes in microseconds while the test was ongoing. In short, PLRUS achieves 10% memory PSI (some) reduction, 14% major page faults reduction, and 3.74% speedup under memory pressure. We also confirmed the CPU usage of kdamond was 2.61% of single CPU, which is below 4% as expected. Sequence of Patches =================== The first and second patch cleans up DAMON debugfs interface and DAMOS_PAGEOUT handling code of physical address space monitoring operations implementation for easier extension of the code. The thrid and fourth patches implement a new DAMOS action called 'lru_prio', which prioritizes pages under memory regions which have a user-specified access pattern, and document it, respectively. The fifth and sixth patches implement yet another new DAMOS action called 'lru_deprio', which deprioritizes pages under memory regions which have a user-specified access pattern, and document it, respectively. The seventh patch implements a static kernel module called 'damon_lru_sort', which utilizes the DAMON-based proactive LRU-lists sorting under conservatively chosen default parameter. Finally, the eighth patch documents 'damon_lru_sort'. This patch (of 8): DAMON debugfs interface assumes users will write 'damos_action' value directly to the 'schemes' file. This makes adding new 'damos_action' in the middle of its definition breaks the backward compatibility of DAMON debugfs interface, as values of some 'damos_action' could be changed. To mitigate the situation, this commit adds mappings between the user inputs and 'damos_action' value and makes DAMON debugfs code uses those. Link: https://lkml.kernel.org/r/20220613192301.8817-1-sj@kernel.org Link: https://lkml.kernel.org/r/20220613192301.8817-2-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit moves code for 'DAMOS_PAGEOUT' handling of the physical address space monitoring operations set to a separate function so that its caller, 'damon_pa_apply_scheme()', can be more easily extended for additional DAMOS actions later. Link: https://lkml.kernel.org/r/20220613192301.8817-4-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit adds a new DAMOS action called 'LRU_PRIO' for the physical address space. The action prioritizes pages in the memory regions of the user-specified target access pattern on their LRU lists. This is hence supposed to be used for frequently accessed (hot) memory regions so that hot pages could be more likely protected under memory pressure. Internally, it simply calls 'mark_page_accessed()'. Link: https://lkml.kernel.org/r/20220613192301.8817-5-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit documents the 'lru_prio' scheme action for DAMON sysfs interface. Link: https://lkml.kernel.org/r/20220613192301.8817-6-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit adds a new DAMON-based operation scheme action called 'LRU_DEPRIO' for physical address space. The action deprioritizes pages in the memory area of the target access pattern on their LRU lists. This is hence supposed to be used for rarely accessed (cold) memory regions so that cold pages could be more likely reclaimed first under memory pressure. Internally, it simply calls 'lru_deactivate()'. Using this with 'LRU_PRIO' action for hot pages, users can proactively sort LRU lists based on the access pattern. That is, it can make the LRU lists somewhat more trustworthy source of access temperature. As a result, efficiency of LRU-lists based mechanisms including the reclamation target selection could be improved. Link: https://lkml.kernel.org/r/20220613192301.8817-7-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit documents the 'LRU_DEPRIO' scheme action for DAMON sysfs interface.` Link: https://lkml.kernel.org/r/20220613192301.8817-8-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Users can do data access-aware LRU-lists sorting using 'LRU_PRIO' and 'LRU_DEPRIO' DAMOS actions. However, finding best parameters including the hotness/coldness thresholds, CPU quota, and watermarks could be challenging for some users. To make the scheme easy to be used without complex tuning for common situations, this commit implements a static kernel module called 'DAMON_LRU_SORT' using the 'LRU_PRIO' and 'LRU_DEPRIO' DAMOS actions. It proactively sorts LRU-lists using DAMON with conservatively chosen default values of the parameters. That is, the module under its default parameters will make no harm for common situations but provide some level of efficiency improvements for systems having clear hot/cold access pattern under a level of memory pressure while consuming only a limited small portion of CPU time. Link: https://lkml.kernel.org/r/20220613192301.8817-9-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit documents the usage of DAMON_LRU_SORT for admins. Link: https://lkml.kernel.org/r/20220613192301.8817-10-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
damon_lru_sort_init() returns an error when damon_select_ops() fails without freeing 'ctx' which allocated before. This commit fixes the potential memory leak by freeing 'ctx' under the situation. Link: https://lkml.kernel.org/r/20220714170458.49727-1-sj@kernel.org Fixes: 40e983c ("mm/damon: introduce DAMON-based LRU-lists Sorting") Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The workflow example code is not working since it got the file names wrong. So fix this. Fixes: b184027 ("Docs/admin-guide/mm/damon/usage: document DAMON sysfs interface") Reviewed-by: SeongJae Park <sj@kernel.org> Signed-off-by: Kairui Song <kasong@tencent.com> Link: https://lore.kernel.org/r/20220823114053.53305-1-ryncsn@gmail.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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…mage commit 42cb74a upstream. WARNING: CPU: 1 PID: 9426 at fs/inode.c:417 drop_nlink+0xac/0xd0 home/cc/linux/fs/inode.c:417 Modules linked in: CPU: 1 UID: 0 PID: 9426 Comm: syz-executor568 Not tainted 6.14.0-12627-g94d471a4f428 #2 PREEMPT(full) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 RIP: 0010:drop_nlink+0xac/0xd0 home/cc/linux/fs/inode.c:417 Code: 48 8b 5d 28 be 08 00 00 00 48 8d bb 70 07 00 00 e8 f9 67 e6 ff f0 48 ff 83 70 07 00 00 5b 5d e9 9a 12 82 ff e8 95 12 82 ff 90 <0f> 0b 90 c7 45 48 ff ff ff ff 5b 5d e9 83 12 82 ff e8 fe 5f e6 ff RSP: 0018:ffffc900026b7c28 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8239710f RDX: ffff888041345a00 RSI: ffffffff8239717b RDI: 0000000000000005 RBP: ffff888054509ad0 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff9ab36f08 R12: ffff88804bb40000 R13: ffff8880545091e0 R14: 0000000000008000 R15: ffff8880545091e0 FS: 000055555d0c5880(0000) GS:ffff8880eb3e3000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f915c55b178 CR3: 0000000050d20000 CR4: 0000000000352ef0 Call Trace: <task> f2fs_i_links_write home/cc/linux/fs/f2fs/f2fs.h:3194 [inline] f2fs_drop_nlink+0xd1/0x3c0 home/cc/linux/fs/f2fs/dir.c:845 f2fs_delete_entry+0x542/0x1450 home/cc/linux/fs/f2fs/dir.c:909 f2fs_unlink+0x45c/0x890 home/cc/linux/fs/f2fs/namei.c:581 vfs_unlink+0x2fb/0x9b0 home/cc/linux/fs/namei.c:4544 do_unlinkat+0x4c5/0x6a0 home/cc/linux/fs/namei.c:4608 __do_sys_unlink home/cc/linux/fs/namei.c:4654 [inline] __se_sys_unlink home/cc/linux/fs/namei.c:4652 [inline] __x64_sys_unlink+0xc5/0x110 home/cc/linux/fs/namei.c:4652 do_syscall_x64 home/cc/linux/arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xc7/0x250 home/cc/linux/arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb3d092324b Code: 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 57 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffdc232d938 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fb3d092324b RDX: 00007ffdc232d960 RSI: 00007ffdc232d960 RDI: 00007ffdc232d9f0 RBP: 00007ffdc232d9f0 R08: 0000000000000001 R09: 00007ffdc232d7c0 R10: 00000000fffffffd R11: 0000000000000206 R12: 00007ffdc232eaf0 R13: 000055555d0cebb0 R14: 00007ffdc232d958 R15: 0000000000000001 </task> Cc: stable@vger.kernel.org Reviewed-by: Chao Yu <chao@kernel.org> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 5d3bc9e ] This patch fixes an issue seen in a large-scale deployment under heavy incoming pkts where the aRFS flow wrongly matches a flow and reprograms the NIC with wrong settings. That mis-steering causes RX-path latency spikes and noisy neighbor effects when many connections collide on the same hash (some of our production servers have 20-30K connections). set_rps_cpu() calls ndo_rx_flow_steer() with flow_id that is calculated by hashing the skb sized by the per rx-queue table size. This results in multiple connections (even across different rx-queues) getting the same hash value. The driver steer function modifies the wrong flow to use this rx-queue, e.g.: Flow#1 is first added: Flow#1: <ip1, port1, ip2, port2>, Hash 'h', q#10 Later when a new flow needs to be added: Flow#2: <ip3, port3, ip4, port4>, Hash 'h', q#20 The driver finds the hash 'h' from Flow#1 and updates it to use q#20. This results in both flows getting un-optimized - packets for Flow#1 goes to q#20, and then reprogrammed back to q#10 later and so on; and Flow #2 programming is never done as Flow#1 is matched first for all misses. Many flows may wrongly share the same hash and reprogram rules of the original flow each with their own q#. Tested on two 144-core servers with 16K netperf sessions for 180s. Netperf clients are pinned to cores 0-71 sequentially (so that wrong packets on q#s 72-143 can be measured). IRQs are set 1:1 for queues -> CPUs, enable XPS, enable aRFS (global value is 144 * rps_flow_cnt). Test notes about results from ice_rx_flow_steer(): --------------------------------------------------- 1. "Skip:" counter increments here: if (fltr_info->q_index == rxq_idx || arfs_entry->fltr_state != ICE_ARFS_ACTIVE) goto out; 2. "Add:" counter increments here: ret = arfs_entry->fltr_info.fltr_id; INIT_HLIST_NODE(&arfs_entry->list_entry); 3. "Update:" counter increments here: /* update the queue to forward to on an already existing flow */ Runtime comparison: original code vs with the patch for different rps_flow_cnt values. +-------------------------------+--------------+--------------+ | rps_flow_cnt | 512 | 2048 | +-------------------------------+--------------+--------------+ | Ratio of Pkts on Good:Bad q's | 214 vs 822K | 1.1M vs 980K | | Avoid wrong aRFS programming | 0 vs 310K | 0 vs 30K | | CPU User | 216 vs 183 | 216 vs 206 | | CPU System | 1441 vs 1171 | 1447 vs 1320 | | CPU Softirq | 1245 vs 920 | 1238 vs 961 | | CPU Total | 29 vs 22.7 | 29 vs 24.9 | | aRFS Update | 533K vs 59 | 521K vs 32 | | aRFS Skip | 82M vs 77M | 7.2M vs 4.5M | +-------------------------------+--------------+--------------+ A separate TCP_STREAM and TCP_RR with 1,4,8,16,64,128,256,512 connections showed no performance degradation. Some points on the patch/aRFS behavior: 1. Enabling full tuple matching ensures flows are always correctly matched, even with smaller hash sizes. 2. 5-6% drop in CPU utilization as the packets arrive at the correct CPUs and fewer calls to driver for programming on misses. 3. Larger hash tables reduces mis-steering due to more unique flow hashes, but still has clashes. However, with larger per-device rps_flow_cnt, old flows take more time to expire and new aRFS flows cannot be added if h/w limits are reached (rps_may_expire_flow() succeeds when 10*rps_flow_cnt pkts have been processed by this cpu that are not part of the flow). Fixes: 28bf267 ("ice: Implement aRFS") Signed-off-by: Krishna Kumar <krikku@gmail.com> Reviewed-by: Simon Horman <horms@kernel.org> Tested-by: Rinitha S <sx.rinitha@intel.com> (A Contingent worker at Intel) Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 10876da ] syzkaller reported a null-ptr-deref in sock_omalloc() while allocating a CALIPSO option. [0] The NULL is of struct sock, which was fetched by sk_to_full_sk() in calipso_req_setattr(). Since commit a1a5344 ("tcp: avoid two atomic ops for syncookies"), reqsk->rsk_listener could be NULL when SYN Cookie is returned to its client, as hinted by the leading SYN Cookie log. Here are 3 options to fix the bug: 1) Return 0 in calipso_req_setattr() 2) Return an error in calipso_req_setattr() 3) Alaways set rsk_listener 1) is no go as it bypasses LSM, but 2) effectively disables SYN Cookie for CALIPSO. 3) is also no go as there have been many efforts to reduce atomic ops and make TCP robust against DDoS. See also commit 3b24d85 ("tcp/dccp: do not touch listener sk_refcnt under synflood"). As of the blamed commit, SYN Cookie already did not need refcounting, and no one has stumbled on the bug for 9 years, so no CALIPSO user will care about SYN Cookie. Let's return an error in calipso_req_setattr() and calipso_req_delattr() in the SYN Cookie case. This can be reproduced by [1] on Fedora and now connect() of nc times out. [0]: TCP: request_sock_TCPv6: Possible SYN flooding on port [::]:20002. Sending cookies. Oops: general protection fault, probably for non-canonical address 0xdffffc0000000006: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037] CPU: 3 UID: 0 PID: 12262 Comm: syz.1.2611 Not tainted 6.14.0 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 RIP: 0010:read_pnet include/net/net_namespace.h:406 [inline] RIP: 0010:sock_net include/net/sock.h:655 [inline] RIP: 0010:sock_kmalloc+0x35/0x170 net/core/sock.c:2806 Code: 89 d5 41 54 55 89 f5 53 48 89 fb e8 25 e3 c6 fd e8 f0 91 e3 00 48 8d 7b 30 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 26 01 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b RSP: 0018:ffff88811af89038 EFLAGS: 00010216 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffff888105266400 RDX: 0000000000000006 RSI: ffff88800c890000 RDI: 0000000000000030 RBP: 0000000000000050 R08: 0000000000000000 R09: ffff88810526640e R10: ffffed1020a4cc81 R11: ffff88810526640f R12: 0000000000000000 R13: 0000000000000820 R14: ffff888105266400 R15: 0000000000000050 FS: 00007f0653a07640(0000) GS:ffff88811af80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f863ba096f4 CR3: 00000000163c0005 CR4: 0000000000770ef0 PKRU: 80000000 Call Trace: <IRQ> ipv6_renew_options+0x279/0x950 net/ipv6/exthdrs.c:1288 calipso_req_setattr+0x181/0x340 net/ipv6/calipso.c:1204 calipso_req_setattr+0x56/0x80 net/netlabel/netlabel_calipso.c:597 netlbl_req_setattr+0x18a/0x440 net/netlabel/netlabel_kapi.c:1249 selinux_netlbl_inet_conn_request+0x1fb/0x320 security/selinux/netlabel.c:342 selinux_inet_conn_request+0x1eb/0x2c0 security/selinux/hooks.c:5551 security_inet_conn_request+0x50/0xa0 security/security.c:4945 tcp_v6_route_req+0x22c/0x550 net/ipv6/tcp_ipv6.c:825 tcp_conn_request+0xec8/0x2b70 net/ipv4/tcp_input.c:7275 tcp_v6_conn_request+0x1e3/0x440 net/ipv6/tcp_ipv6.c:1328 tcp_rcv_state_process+0xafa/0x52b0 net/ipv4/tcp_input.c:6781 tcp_v6_do_rcv+0x8a6/0x1a40 net/ipv6/tcp_ipv6.c:1667 tcp_v6_rcv+0x505e/0x5b50 net/ipv6/tcp_ipv6.c:1904 ip6_protocol_deliver_rcu+0x17c/0x1da0 net/ipv6/ip6_input.c:436 ip6_input_finish+0x103/0x180 net/ipv6/ip6_input.c:480 NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] ip6_input+0x13c/0x6b0 net/ipv6/ip6_input.c:491 dst_input include/net/dst.h:469 [inline] ip6_rcv_finish net/ipv6/ip6_input.c:79 [inline] ip6_rcv_finish+0xb6/0x490 net/ipv6/ip6_input.c:69 NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] ipv6_rcv+0xf9/0x490 net/ipv6/ip6_input.c:309 __netif_receive_skb_one_core+0x12e/0x1f0 net/core/dev.c:5896 __netif_receive_skb+0x1d/0x170 net/core/dev.c:6009 process_backlog+0x41e/0x13b0 net/core/dev.c:6357 __napi_poll+0xbd/0x710 net/core/dev.c:7191 napi_poll net/core/dev.c:7260 [inline] net_rx_action+0x9de/0xde0 net/core/dev.c:7382 handle_softirqs+0x19a/0x770 kernel/softirq.c:561 do_softirq.part.0+0x36/0x70 kernel/softirq.c:462 </IRQ> <TASK> do_softirq arch/x86/include/asm/preempt.h:26 [inline] __local_bh_enable_ip+0xf1/0x110 kernel/softirq.c:389 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:919 [inline] __dev_queue_xmit+0xc2a/0x3c40 net/core/dev.c:4679 dev_queue_xmit include/linux/netdevice.h:3313 [inline] neigh_hh_output include/net/neighbour.h:523 [inline] neigh_output include/net/neighbour.h:537 [inline] ip6_finish_output2+0xd69/0x1f80 net/ipv6/ip6_output.c:141 __ip6_finish_output net/ipv6/ip6_output.c:215 [inline] ip6_finish_output+0x5dc/0xd60 net/ipv6/ip6_output.c:226 NF_HOOK_COND include/linux/netfilter.h:303 [inline] ip6_output+0x24b/0x8d0 net/ipv6/ip6_output.c:247 dst_output include/net/dst.h:459 [inline] NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] ip6_xmit+0xbbc/0x20d0 net/ipv6/ip6_output.c:366 inet6_csk_xmit+0x39a/0x720 net/ipv6/inet6_connection_sock.c:135 __tcp_transmit_skb+0x1a7b/0x3b40 net/ipv4/tcp_output.c:1471 tcp_transmit_skb net/ipv4/tcp_output.c:1489 [inline] tcp_send_syn_data net/ipv4/tcp_output.c:4059 [inline] tcp_connect+0x1c0c/0x4510 net/ipv4/tcp_output.c:4148 tcp_v6_connect+0x156c/0x2080 net/ipv6/tcp_ipv6.c:333 __inet_stream_connect+0x3a7/0xed0 net/ipv4/af_inet.c:677 tcp_sendmsg_fastopen+0x3e2/0x710 net/ipv4/tcp.c:1039 tcp_sendmsg_locked+0x1e82/0x3570 net/ipv4/tcp.c:1091 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1358 inet6_sendmsg+0xb9/0x150 net/ipv6/af_inet6.c:659 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg+0xf4/0x2a0 net/socket.c:733 __sys_sendto+0x29a/0x390 net/socket.c:2187 __do_sys_sendto net/socket.c:2194 [inline] __se_sys_sendto net/socket.c:2190 [inline] __x64_sys_sendto+0xe1/0x1c0 net/socket.c:2190 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xc3/0x1d0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f06553c47ed Code: 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f0653a06fc8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f0655605fa0 RCX: 00007f06553c47ed RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000000000b RBP: 00007f065545db38 R08: 0000200000000140 R09: 000000000000001c R10: f7384d4ea84b01bd R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0655605fac R14: 00007f0655606038 R15: 00007f06539e7000 </TASK> Modules linked in: [1]: dnf install -y selinux-policy-targeted policycoreutils netlabel_tools procps-ng nmap-ncat mount -t selinuxfs none /sys/fs/selinux load_policy netlabelctl calipso add pass doi:1 netlabelctl map del default netlabelctl map add default address:::1 protocol:calipso,1 sysctl net.ipv4.tcp_syncookies=2 nc -l ::1 80 & nc ::1 80 Fixes: e1adea9 ("calipso: Allow request sockets to be relabelled by the lsm.") Reported-by: syzkaller <syzkaller@googlegroups.com> Reported-by: John Cheung <john.cs.hey@gmail.com> Closes: https://lore.kernel.org/netdev/CAP=Rh=MvfhrGADy+-WJiftV2_WzMH4VEhEFmeT28qY+4yxNu4w@mail.gmail.com/ Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Acked-by: Paul Moore <paul@paul-moore.com> Link: https://patch.msgid.link/20250617224125.17299-1-kuni1840@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 6aba0cb ] As-per the SBI specification, an SBI remote fence operation applies to the entire address space if either: 1) start_addr and size are both 0 2) size is equal to 2^XLEN-1 >From the above, only #1 is checked by SBI SFENCE calls so fix the size parameter check in SBI SFENCE calls to cover #2 as well. Fixes: 13acfec ("RISC-V: KVM: Add remote HFENCE functions based on VCPU requests") Reviewed-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <apatel@ventanamicro.com> Link: https://lore.kernel.org/r/20250605061458.196003-2-apatel@ventanamicro.com Signed-off-by: Anup Patel <anup@brainfault.org> 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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…mage commit 42cb74a upstream. WARNING: CPU: 1 PID: 9426 at fs/inode.c:417 drop_nlink+0xac/0xd0 home/cc/linux/fs/inode.c:417 Modules linked in: CPU: 1 UID: 0 PID: 9426 Comm: syz-executor568 Not tainted 6.14.0-12627-g94d471a4f428 #2 PREEMPT(full) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 RIP: 0010:drop_nlink+0xac/0xd0 home/cc/linux/fs/inode.c:417 Code: 48 8b 5d 28 be 08 00 00 00 48 8d bb 70 07 00 00 e8 f9 67 e6 ff f0 48 ff 83 70 07 00 00 5b 5d e9 9a 12 82 ff e8 95 12 82 ff 90 <0f> 0b 90 c7 45 48 ff ff ff ff 5b 5d e9 83 12 82 ff e8 fe 5f e6 ff RSP: 0018:ffffc900026b7c28 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8239710f RDX: ffff888041345a00 RSI: ffffffff8239717b RDI: 0000000000000005 RBP: ffff888054509ad0 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff9ab36f08 R12: ffff88804bb40000 R13: ffff8880545091e0 R14: 0000000000008000 R15: ffff8880545091e0 FS: 000055555d0c5880(0000) GS:ffff8880eb3e3000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f915c55b178 CR3: 0000000050d20000 CR4: 0000000000352ef0 Call Trace: <task> f2fs_i_links_write home/cc/linux/fs/f2fs/f2fs.h:3194 [inline] f2fs_drop_nlink+0xd1/0x3c0 home/cc/linux/fs/f2fs/dir.c:845 f2fs_delete_entry+0x542/0x1450 home/cc/linux/fs/f2fs/dir.c:909 f2fs_unlink+0x45c/0x890 home/cc/linux/fs/f2fs/namei.c:581 vfs_unlink+0x2fb/0x9b0 home/cc/linux/fs/namei.c:4544 do_unlinkat+0x4c5/0x6a0 home/cc/linux/fs/namei.c:4608 __do_sys_unlink home/cc/linux/fs/namei.c:4654 [inline] __se_sys_unlink home/cc/linux/fs/namei.c:4652 [inline] __x64_sys_unlink+0xc5/0x110 home/cc/linux/fs/namei.c:4652 do_syscall_x64 home/cc/linux/arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xc7/0x250 home/cc/linux/arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb3d092324b Code: 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 57 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffdc232d938 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fb3d092324b RDX: 00007ffdc232d960 RSI: 00007ffdc232d960 RDI: 00007ffdc232d9f0 RBP: 00007ffdc232d9f0 R08: 0000000000000001 R09: 00007ffdc232d7c0 R10: 00000000fffffffd R11: 0000000000000206 R12: 00007ffdc232eaf0 R13: 000055555d0cebb0 R14: 00007ffdc232d958 R15: 0000000000000001 </task> Cc: stable@vger.kernel.org Reviewed-by: Chao Yu <chao@kernel.org> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 5d3bc9e ] This patch fixes an issue seen in a large-scale deployment under heavy incoming pkts where the aRFS flow wrongly matches a flow and reprograms the NIC with wrong settings. That mis-steering causes RX-path latency spikes and noisy neighbor effects when many connections collide on the same hash (some of our production servers have 20-30K connections). set_rps_cpu() calls ndo_rx_flow_steer() with flow_id that is calculated by hashing the skb sized by the per rx-queue table size. This results in multiple connections (even across different rx-queues) getting the same hash value. The driver steer function modifies the wrong flow to use this rx-queue, e.g.: Flow#1 is first added: Flow#1: <ip1, port1, ip2, port2>, Hash 'h', q#10 Later when a new flow needs to be added: Flow#2: <ip3, port3, ip4, port4>, Hash 'h', q#20 The driver finds the hash 'h' from Flow#1 and updates it to use q#20. This results in both flows getting un-optimized - packets for Flow#1 goes to q#20, and then reprogrammed back to q#10 later and so on; and Flow #2 programming is never done as Flow#1 is matched first for all misses. Many flows may wrongly share the same hash and reprogram rules of the original flow each with their own q#. Tested on two 144-core servers with 16K netperf sessions for 180s. Netperf clients are pinned to cores 0-71 sequentially (so that wrong packets on q#s 72-143 can be measured). IRQs are set 1:1 for queues -> CPUs, enable XPS, enable aRFS (global value is 144 * rps_flow_cnt). Test notes about results from ice_rx_flow_steer(): --------------------------------------------------- 1. "Skip:" counter increments here: if (fltr_info->q_index == rxq_idx || arfs_entry->fltr_state != ICE_ARFS_ACTIVE) goto out; 2. "Add:" counter increments here: ret = arfs_entry->fltr_info.fltr_id; INIT_HLIST_NODE(&arfs_entry->list_entry); 3. "Update:" counter increments here: /* update the queue to forward to on an already existing flow */ Runtime comparison: original code vs with the patch for different rps_flow_cnt values. +-------------------------------+--------------+--------------+ | rps_flow_cnt | 512 | 2048 | +-------------------------------+--------------+--------------+ | Ratio of Pkts on Good:Bad q's | 214 vs 822K | 1.1M vs 980K | | Avoid wrong aRFS programming | 0 vs 310K | 0 vs 30K | | CPU User | 216 vs 183 | 216 vs 206 | | CPU System | 1441 vs 1171 | 1447 vs 1320 | | CPU Softirq | 1245 vs 920 | 1238 vs 961 | | CPU Total | 29 vs 22.7 | 29 vs 24.9 | | aRFS Update | 533K vs 59 | 521K vs 32 | | aRFS Skip | 82M vs 77M | 7.2M vs 4.5M | +-------------------------------+--------------+--------------+ A separate TCP_STREAM and TCP_RR with 1,4,8,16,64,128,256,512 connections showed no performance degradation. Some points on the patch/aRFS behavior: 1. Enabling full tuple matching ensures flows are always correctly matched, even with smaller hash sizes. 2. 5-6% drop in CPU utilization as the packets arrive at the correct CPUs and fewer calls to driver for programming on misses. 3. Larger hash tables reduces mis-steering due to more unique flow hashes, but still has clashes. However, with larger per-device rps_flow_cnt, old flows take more time to expire and new aRFS flows cannot be added if h/w limits are reached (rps_may_expire_flow() succeeds when 10*rps_flow_cnt pkts have been processed by this cpu that are not part of the flow). Fixes: 28bf267 ("ice: Implement aRFS") Signed-off-by: Krishna Kumar <krikku@gmail.com> Reviewed-by: Simon Horman <horms@kernel.org> Tested-by: Rinitha S <sx.rinitha@intel.com> (A Contingent worker at Intel) Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 10876da ] syzkaller reported a null-ptr-deref in sock_omalloc() while allocating a CALIPSO option. [0] The NULL is of struct sock, which was fetched by sk_to_full_sk() in calipso_req_setattr(). Since commit a1a5344 ("tcp: avoid two atomic ops for syncookies"), reqsk->rsk_listener could be NULL when SYN Cookie is returned to its client, as hinted by the leading SYN Cookie log. Here are 3 options to fix the bug: 1) Return 0 in calipso_req_setattr() 2) Return an error in calipso_req_setattr() 3) Alaways set rsk_listener 1) is no go as it bypasses LSM, but 2) effectively disables SYN Cookie for CALIPSO. 3) is also no go as there have been many efforts to reduce atomic ops and make TCP robust against DDoS. See also commit 3b24d85 ("tcp/dccp: do not touch listener sk_refcnt under synflood"). As of the blamed commit, SYN Cookie already did not need refcounting, and no one has stumbled on the bug for 9 years, so no CALIPSO user will care about SYN Cookie. Let's return an error in calipso_req_setattr() and calipso_req_delattr() in the SYN Cookie case. This can be reproduced by [1] on Fedora and now connect() of nc times out. [0]: TCP: request_sock_TCPv6: Possible SYN flooding on port [::]:20002. Sending cookies. Oops: general protection fault, probably for non-canonical address 0xdffffc0000000006: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037] CPU: 3 UID: 0 PID: 12262 Comm: syz.1.2611 Not tainted 6.14.0 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 RIP: 0010:read_pnet include/net/net_namespace.h:406 [inline] RIP: 0010:sock_net include/net/sock.h:655 [inline] RIP: 0010:sock_kmalloc+0x35/0x170 net/core/sock.c:2806 Code: 89 d5 41 54 55 89 f5 53 48 89 fb e8 25 e3 c6 fd e8 f0 91 e3 00 48 8d 7b 30 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 26 01 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b RSP: 0018:ffff88811af89038 EFLAGS: 00010216 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffff888105266400 RDX: 0000000000000006 RSI: ffff88800c890000 RDI: 0000000000000030 RBP: 0000000000000050 R08: 0000000000000000 R09: ffff88810526640e R10: ffffed1020a4cc81 R11: ffff88810526640f R12: 0000000000000000 R13: 0000000000000820 R14: ffff888105266400 R15: 0000000000000050 FS: 00007f0653a07640(0000) GS:ffff88811af80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f863ba096f4 CR3: 00000000163c0005 CR4: 0000000000770ef0 PKRU: 80000000 Call Trace: <IRQ> ipv6_renew_options+0x279/0x950 net/ipv6/exthdrs.c:1288 calipso_req_setattr+0x181/0x340 net/ipv6/calipso.c:1204 calipso_req_setattr+0x56/0x80 net/netlabel/netlabel_calipso.c:597 netlbl_req_setattr+0x18a/0x440 net/netlabel/netlabel_kapi.c:1249 selinux_netlbl_inet_conn_request+0x1fb/0x320 security/selinux/netlabel.c:342 selinux_inet_conn_request+0x1eb/0x2c0 security/selinux/hooks.c:5551 security_inet_conn_request+0x50/0xa0 security/security.c:4945 tcp_v6_route_req+0x22c/0x550 net/ipv6/tcp_ipv6.c:825 tcp_conn_request+0xec8/0x2b70 net/ipv4/tcp_input.c:7275 tcp_v6_conn_request+0x1e3/0x440 net/ipv6/tcp_ipv6.c:1328 tcp_rcv_state_process+0xafa/0x52b0 net/ipv4/tcp_input.c:6781 tcp_v6_do_rcv+0x8a6/0x1a40 net/ipv6/tcp_ipv6.c:1667 tcp_v6_rcv+0x505e/0x5b50 net/ipv6/tcp_ipv6.c:1904 ip6_protocol_deliver_rcu+0x17c/0x1da0 net/ipv6/ip6_input.c:436 ip6_input_finish+0x103/0x180 net/ipv6/ip6_input.c:480 NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] ip6_input+0x13c/0x6b0 net/ipv6/ip6_input.c:491 dst_input include/net/dst.h:469 [inline] ip6_rcv_finish net/ipv6/ip6_input.c:79 [inline] ip6_rcv_finish+0xb6/0x490 net/ipv6/ip6_input.c:69 NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] ipv6_rcv+0xf9/0x490 net/ipv6/ip6_input.c:309 __netif_receive_skb_one_core+0x12e/0x1f0 net/core/dev.c:5896 __netif_receive_skb+0x1d/0x170 net/core/dev.c:6009 process_backlog+0x41e/0x13b0 net/core/dev.c:6357 __napi_poll+0xbd/0x710 net/core/dev.c:7191 napi_poll net/core/dev.c:7260 [inline] net_rx_action+0x9de/0xde0 net/core/dev.c:7382 handle_softirqs+0x19a/0x770 kernel/softirq.c:561 do_softirq.part.0+0x36/0x70 kernel/softirq.c:462 </IRQ> <TASK> do_softirq arch/x86/include/asm/preempt.h:26 [inline] __local_bh_enable_ip+0xf1/0x110 kernel/softirq.c:389 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:919 [inline] __dev_queue_xmit+0xc2a/0x3c40 net/core/dev.c:4679 dev_queue_xmit include/linux/netdevice.h:3313 [inline] neigh_hh_output include/net/neighbour.h:523 [inline] neigh_output include/net/neighbour.h:537 [inline] ip6_finish_output2+0xd69/0x1f80 net/ipv6/ip6_output.c:141 __ip6_finish_output net/ipv6/ip6_output.c:215 [inline] ip6_finish_output+0x5dc/0xd60 net/ipv6/ip6_output.c:226 NF_HOOK_COND include/linux/netfilter.h:303 [inline] ip6_output+0x24b/0x8d0 net/ipv6/ip6_output.c:247 dst_output include/net/dst.h:459 [inline] NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] ip6_xmit+0xbbc/0x20d0 net/ipv6/ip6_output.c:366 inet6_csk_xmit+0x39a/0x720 net/ipv6/inet6_connection_sock.c:135 __tcp_transmit_skb+0x1a7b/0x3b40 net/ipv4/tcp_output.c:1471 tcp_transmit_skb net/ipv4/tcp_output.c:1489 [inline] tcp_send_syn_data net/ipv4/tcp_output.c:4059 [inline] tcp_connect+0x1c0c/0x4510 net/ipv4/tcp_output.c:4148 tcp_v6_connect+0x156c/0x2080 net/ipv6/tcp_ipv6.c:333 __inet_stream_connect+0x3a7/0xed0 net/ipv4/af_inet.c:677 tcp_sendmsg_fastopen+0x3e2/0x710 net/ipv4/tcp.c:1039 tcp_sendmsg_locked+0x1e82/0x3570 net/ipv4/tcp.c:1091 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1358 inet6_sendmsg+0xb9/0x150 net/ipv6/af_inet6.c:659 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg+0xf4/0x2a0 net/socket.c:733 __sys_sendto+0x29a/0x390 net/socket.c:2187 __do_sys_sendto net/socket.c:2194 [inline] __se_sys_sendto net/socket.c:2190 [inline] __x64_sys_sendto+0xe1/0x1c0 net/socket.c:2190 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xc3/0x1d0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f06553c47ed Code: 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f0653a06fc8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f0655605fa0 RCX: 00007f06553c47ed RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000000000b RBP: 00007f065545db38 R08: 0000200000000140 R09: 000000000000001c R10: f7384d4ea84b01bd R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0655605fac R14: 00007f0655606038 R15: 00007f06539e7000 </TASK> Modules linked in: [1]: dnf install -y selinux-policy-targeted policycoreutils netlabel_tools procps-ng nmap-ncat mount -t selinuxfs none /sys/fs/selinux load_policy netlabelctl calipso add pass doi:1 netlabelctl map del default netlabelctl map add default address:::1 protocol:calipso,1 sysctl net.ipv4.tcp_syncookies=2 nc -l ::1 80 & nc ::1 80 Fixes: e1adea9 ("calipso: Allow request sockets to be relabelled by the lsm.") Reported-by: syzkaller <syzkaller@googlegroups.com> Reported-by: John Cheung <john.cs.hey@gmail.com> Closes: https://lore.kernel.org/netdev/CAP=Rh=MvfhrGADy+-WJiftV2_WzMH4VEhEFmeT28qY+4yxNu4w@mail.gmail.com/ Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Acked-by: Paul Moore <paul@paul-moore.com> Link: https://patch.msgid.link/20250617224125.17299-1-kuni1840@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
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…mage commit 42cb74a upstream. WARNING: CPU: 1 PID: 9426 at fs/inode.c:417 drop_nlink+0xac/0xd0 home/cc/linux/fs/inode.c:417 Modules linked in: CPU: 1 UID: 0 PID: 9426 Comm: syz-executor568 Not tainted 6.14.0-12627-g94d471a4f428 #2 PREEMPT(full) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 RIP: 0010:drop_nlink+0xac/0xd0 home/cc/linux/fs/inode.c:417 Code: 48 8b 5d 28 be 08 00 00 00 48 8d bb 70 07 00 00 e8 f9 67 e6 ff f0 48 ff 83 70 07 00 00 5b 5d e9 9a 12 82 ff e8 95 12 82 ff 90 <0f> 0b 90 c7 45 48 ff ff ff ff 5b 5d e9 83 12 82 ff e8 fe 5f e6 ff RSP: 0018:ffffc900026b7c28 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8239710f RDX: ffff888041345a00 RSI: ffffffff8239717b RDI: 0000000000000005 RBP: ffff888054509ad0 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff9ab36f08 R12: ffff88804bb40000 R13: ffff8880545091e0 R14: 0000000000008000 R15: ffff8880545091e0 FS: 000055555d0c5880(0000) GS:ffff8880eb3e3000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f915c55b178 CR3: 0000000050d20000 CR4: 0000000000352ef0 Call Trace: <task> f2fs_i_links_write home/cc/linux/fs/f2fs/f2fs.h:3194 [inline] f2fs_drop_nlink+0xd1/0x3c0 home/cc/linux/fs/f2fs/dir.c:845 f2fs_delete_entry+0x542/0x1450 home/cc/linux/fs/f2fs/dir.c:909 f2fs_unlink+0x45c/0x890 home/cc/linux/fs/f2fs/namei.c:581 vfs_unlink+0x2fb/0x9b0 home/cc/linux/fs/namei.c:4544 do_unlinkat+0x4c5/0x6a0 home/cc/linux/fs/namei.c:4608 __do_sys_unlink home/cc/linux/fs/namei.c:4654 [inline] __se_sys_unlink home/cc/linux/fs/namei.c:4652 [inline] __x64_sys_unlink+0xc5/0x110 home/cc/linux/fs/namei.c:4652 do_syscall_x64 home/cc/linux/arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xc7/0x250 home/cc/linux/arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb3d092324b Code: 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 57 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffdc232d938 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fb3d092324b RDX: 00007ffdc232d960 RSI: 00007ffdc232d960 RDI: 00007ffdc232d9f0 RBP: 00007ffdc232d9f0 R08: 0000000000000001 R09: 00007ffdc232d7c0 R10: 00000000fffffffd R11: 0000000000000206 R12: 00007ffdc232eaf0 R13: 000055555d0cebb0 R14: 00007ffdc232d958 R15: 0000000000000001 </task> Cc: stable@vger.kernel.org Reviewed-by: Chao Yu <chao@kernel.org> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 10876da ] syzkaller reported a null-ptr-deref in sock_omalloc() while allocating a CALIPSO option. [0] The NULL is of struct sock, which was fetched by sk_to_full_sk() in calipso_req_setattr(). Since commit a1a5344 ("tcp: avoid two atomic ops for syncookies"), reqsk->rsk_listener could be NULL when SYN Cookie is returned to its client, as hinted by the leading SYN Cookie log. Here are 3 options to fix the bug: 1) Return 0 in calipso_req_setattr() 2) Return an error in calipso_req_setattr() 3) Alaways set rsk_listener 1) is no go as it bypasses LSM, but 2) effectively disables SYN Cookie for CALIPSO. 3) is also no go as there have been many efforts to reduce atomic ops and make TCP robust against DDoS. See also commit 3b24d85 ("tcp/dccp: do not touch listener sk_refcnt under synflood"). As of the blamed commit, SYN Cookie already did not need refcounting, and no one has stumbled on the bug for 9 years, so no CALIPSO user will care about SYN Cookie. Let's return an error in calipso_req_setattr() and calipso_req_delattr() in the SYN Cookie case. This can be reproduced by [1] on Fedora and now connect() of nc times out. [0]: TCP: request_sock_TCPv6: Possible SYN flooding on port [::]:20002. Sending cookies. Oops: general protection fault, probably for non-canonical address 0xdffffc0000000006: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037] CPU: 3 UID: 0 PID: 12262 Comm: syz.1.2611 Not tainted 6.14.0 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 RIP: 0010:read_pnet include/net/net_namespace.h:406 [inline] RIP: 0010:sock_net include/net/sock.h:655 [inline] RIP: 0010:sock_kmalloc+0x35/0x170 net/core/sock.c:2806 Code: 89 d5 41 54 55 89 f5 53 48 89 fb e8 25 e3 c6 fd e8 f0 91 e3 00 48 8d 7b 30 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 26 01 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b RSP: 0018:ffff88811af89038 EFLAGS: 00010216 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffff888105266400 RDX: 0000000000000006 RSI: ffff88800c890000 RDI: 0000000000000030 RBP: 0000000000000050 R08: 0000000000000000 R09: ffff88810526640e R10: ffffed1020a4cc81 R11: ffff88810526640f R12: 0000000000000000 R13: 0000000000000820 R14: ffff888105266400 R15: 0000000000000050 FS: 00007f0653a07640(0000) GS:ffff88811af80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f863ba096f4 CR3: 00000000163c0005 CR4: 0000000000770ef0 PKRU: 80000000 Call Trace: <IRQ> ipv6_renew_options+0x279/0x950 net/ipv6/exthdrs.c:1288 calipso_req_setattr+0x181/0x340 net/ipv6/calipso.c:1204 calipso_req_setattr+0x56/0x80 net/netlabel/netlabel_calipso.c:597 netlbl_req_setattr+0x18a/0x440 net/netlabel/netlabel_kapi.c:1249 selinux_netlbl_inet_conn_request+0x1fb/0x320 security/selinux/netlabel.c:342 selinux_inet_conn_request+0x1eb/0x2c0 security/selinux/hooks.c:5551 security_inet_conn_request+0x50/0xa0 security/security.c:4945 tcp_v6_route_req+0x22c/0x550 net/ipv6/tcp_ipv6.c:825 tcp_conn_request+0xec8/0x2b70 net/ipv4/tcp_input.c:7275 tcp_v6_conn_request+0x1e3/0x440 net/ipv6/tcp_ipv6.c:1328 tcp_rcv_state_process+0xafa/0x52b0 net/ipv4/tcp_input.c:6781 tcp_v6_do_rcv+0x8a6/0x1a40 net/ipv6/tcp_ipv6.c:1667 tcp_v6_rcv+0x505e/0x5b50 net/ipv6/tcp_ipv6.c:1904 ip6_protocol_deliver_rcu+0x17c/0x1da0 net/ipv6/ip6_input.c:436 ip6_input_finish+0x103/0x180 net/ipv6/ip6_input.c:480 NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] ip6_input+0x13c/0x6b0 net/ipv6/ip6_input.c:491 dst_input include/net/dst.h:469 [inline] ip6_rcv_finish net/ipv6/ip6_input.c:79 [inline] ip6_rcv_finish+0xb6/0x490 net/ipv6/ip6_input.c:69 NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] ipv6_rcv+0xf9/0x490 net/ipv6/ip6_input.c:309 __netif_receive_skb_one_core+0x12e/0x1f0 net/core/dev.c:5896 __netif_receive_skb+0x1d/0x170 net/core/dev.c:6009 process_backlog+0x41e/0x13b0 net/core/dev.c:6357 __napi_poll+0xbd/0x710 net/core/dev.c:7191 napi_poll net/core/dev.c:7260 [inline] net_rx_action+0x9de/0xde0 net/core/dev.c:7382 handle_softirqs+0x19a/0x770 kernel/softirq.c:561 do_softirq.part.0+0x36/0x70 kernel/softirq.c:462 </IRQ> <TASK> do_softirq arch/x86/include/asm/preempt.h:26 [inline] __local_bh_enable_ip+0xf1/0x110 kernel/softirq.c:389 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:919 [inline] __dev_queue_xmit+0xc2a/0x3c40 net/core/dev.c:4679 dev_queue_xmit include/linux/netdevice.h:3313 [inline] neigh_hh_output include/net/neighbour.h:523 [inline] neigh_output include/net/neighbour.h:537 [inline] ip6_finish_output2+0xd69/0x1f80 net/ipv6/ip6_output.c:141 __ip6_finish_output net/ipv6/ip6_output.c:215 [inline] ip6_finish_output+0x5dc/0xd60 net/ipv6/ip6_output.c:226 NF_HOOK_COND include/linux/netfilter.h:303 [inline] ip6_output+0x24b/0x8d0 net/ipv6/ip6_output.c:247 dst_output include/net/dst.h:459 [inline] NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] ip6_xmit+0xbbc/0x20d0 net/ipv6/ip6_output.c:366 inet6_csk_xmit+0x39a/0x720 net/ipv6/inet6_connection_sock.c:135 __tcp_transmit_skb+0x1a7b/0x3b40 net/ipv4/tcp_output.c:1471 tcp_transmit_skb net/ipv4/tcp_output.c:1489 [inline] tcp_send_syn_data net/ipv4/tcp_output.c:4059 [inline] tcp_connect+0x1c0c/0x4510 net/ipv4/tcp_output.c:4148 tcp_v6_connect+0x156c/0x2080 net/ipv6/tcp_ipv6.c:333 __inet_stream_connect+0x3a7/0xed0 net/ipv4/af_inet.c:677 tcp_sendmsg_fastopen+0x3e2/0x710 net/ipv4/tcp.c:1039 tcp_sendmsg_locked+0x1e82/0x3570 net/ipv4/tcp.c:1091 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1358 inet6_sendmsg+0xb9/0x150 net/ipv6/af_inet6.c:659 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg+0xf4/0x2a0 net/socket.c:733 __sys_sendto+0x29a/0x390 net/socket.c:2187 __do_sys_sendto net/socket.c:2194 [inline] __se_sys_sendto net/socket.c:2190 [inline] __x64_sys_sendto+0xe1/0x1c0 net/socket.c:2190 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xc3/0x1d0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f06553c47ed Code: 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f0653a06fc8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f0655605fa0 RCX: 00007f06553c47ed RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000000000b RBP: 00007f065545db38 R08: 0000200000000140 R09: 000000000000001c R10: f7384d4ea84b01bd R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0655605fac R14: 00007f0655606038 R15: 00007f06539e7000 </TASK> Modules linked in: [1]: dnf install -y selinux-policy-targeted policycoreutils netlabel_tools procps-ng nmap-ncat mount -t selinuxfs none /sys/fs/selinux load_policy netlabelctl calipso add pass doi:1 netlabelctl map del default netlabelctl map add default address:::1 protocol:calipso,1 sysctl net.ipv4.tcp_syncookies=2 nc -l ::1 80 & nc ::1 80 Fixes: e1adea9 ("calipso: Allow request sockets to be relabelled by the lsm.") Reported-by: syzkaller <syzkaller@googlegroups.com> Reported-by: John Cheung <john.cs.hey@gmail.com> Closes: https://lore.kernel.org/netdev/CAP=Rh=MvfhrGADy+-WJiftV2_WzMH4VEhEFmeT28qY+4yxNu4w@mail.gmail.com/ Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Acked-by: Paul Moore <paul@paul-moore.com> Link: https://patch.msgid.link/20250617224125.17299-1-kuni1840@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
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Aishwarya reports that warnings are sometimes seen when running the ftrace kselftests, e.g. | WARNING: CPU: 5 PID: 2066 at arch/arm64/kernel/stacktrace.c:141 arch_stack_walk+0x4a0/0x4c0 | Modules linked in: | CPU: 5 UID: 0 PID: 2066 Comm: ftracetest Not tainted 6.13.0-rc2 #2 | Hardware name: linux,dummy-virt (DT) | pstate: 604000c5 (nZCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--) | pc : arch_stack_walk+0x4a0/0x4c0 | lr : arch_stack_walk+0x248/0x4c0 | sp : ffff800083643d20 | x29: ffff800083643dd0 x28: ffff00007b891400 x27: ffff00007b891928 | x26: 0000000000000001 x25: 00000000000000c0 x24: ffff800082f39d80 | x23: ffff80008003ee8c x22: ffff80008004baa8 x21: ffff8000800533e0 | x20: ffff800083643e10 x19: ffff80008003eec8 x18: 0000000000000000 | x17: 0000000000000000 x16: ffff800083640000 x15: 0000000000000000 | x14: 02a37a802bbb8a92 x13: 00000000000001a9 x12: 0000000000000001 | x11: ffff800082ffad60 x10: ffff800083643d20 x9 : ffff80008003eed0 | x8 : ffff80008004baa8 x7 : ffff800086f2be80 x6 : ffff0000057cf000 | x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff800086f2b690 | x2 : ffff80008004baa8 x1 : ffff80008004baa8 x0 : ffff80008004baa8 | Call trace: | arch_stack_walk+0x4a0/0x4c0 (P) | arch_stack_walk+0x248/0x4c0 (L) | profile_pc+0x44/0x80 | profile_tick+0x50/0x80 (F) | tick_nohz_handler+0xcc/0x160 (F) | __hrtimer_run_queues+0x2ac/0x340 (F) | hrtimer_interrupt+0xf4/0x268 (F) | arch_timer_handler_virt+0x34/0x60 (F) | handle_percpu_devid_irq+0x88/0x220 (F) | generic_handle_domain_irq+0x34/0x60 (F) | gic_handle_irq+0x54/0x140 (F) | call_on_irq_stack+0x24/0x58 (F) | do_interrupt_handler+0x88/0x98 | el1_interrupt+0x34/0x68 (F) | el1h_64_irq_handler+0x18/0x28 | el1h_64_irq+0x6c/0x70 | queued_spin_lock_slowpath+0x78/0x460 (P) The warning in question is: WARN_ON_ONCE(state->common.pc == orig_pc)) ... in kunwind_recover_return_address(), which is triggered when return_to_handler() is encountered in the trace, but ftrace_graph_ret_addr() cannot find a corresponding original return address on the fgraph return stack. This happens because the stacktrace code encounters an exception boundary where the LR was not live at the time of the exception, but the LR happens to contain return_to_handler(); either because the task recently returned there, or due to unfortunate usage of the LR at a scratch register. In such cases attempts to recover the return address via ftrace_graph_ret_addr() may fail, triggering the WARN_ON_ONCE() above and aborting the unwind (hence the stacktrace terminating after reporting the PC at the time of the exception). Handling unreliable LR values in these cases is likely to require some larger rework, so for the moment avoid this problem by restoring the old behaviour of skipping the LR at exception boundaries, which the stacktrace code did prior to commit: c2c6b27 ("arm64: stacktrace: unwind exception boundaries") This commit is effectively a partial revert, keeping the structures and logic to explicitly identify exception boundaries while still skipping reporting of the LR. The logic to explicitly identify exception boundaries is still useful for general robustness and as a building block for future support for RELIABLE_STACKTRACE. Fixes: c2c6b27 ("arm64: stacktrace: unwind exception boundaries") Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reported-by: Aishwarya TCV <aishwarya.tcv@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20241211140704.2498712-2-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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The arm64 stacktrace code has a few error conditions where a
WARN_ON_ONCE() is triggered before the stacktrace is terminated and an
error is returned to the caller. The conditions shouldn't be triggered
when unwinding the current task, but it is possible to trigger these
when unwinding another task which is not blocked, as the stack of that
task is concurrently modified. Kent reports that these warnings can be
triggered while running filesystem tests on bcachefs, which calls the
stacktrace code directly.
To produce a meaningful stacktrace of another task, the task in question
should be blocked, but the stacktrace code is expected to be robust to
cases where it is not blocked. Note that this is purely about not
unuduly scaring the user and/or crashing the kernel; stacktraces in such
cases are meaningless and may leak kernel secrets from the stack of the
task being unwound.
Ideally we'd pin the task in a blocked state during the unwind, as we do
for /proc/${PID}/wchan since commit:
42a20f8 ("sched: Add wrapper for get_wchan() to keep task blocked")
... but a bunch of places don't do that, notably /proc/${PID}/stack,
where we don't pin the task in a blocked state, but do restrict the
output to privileged users since commit:
f8a00ce ("proc: restrict kernel stack dumps to root")
... and so it's possible to trigger these warnings accidentally, e.g. by
reading /proc/*/stack (as root):
| for n in $(seq 1 10); do
| while true; do cat /proc/*/stack > /dev/null 2>&1; done &
| done
| ------------[ cut here ]------------
| WARNING: CPU: 3 PID: 166 at arch/arm64/kernel/stacktrace.c:207 arch_stack_walk+0x1c8/0x370
| Modules linked in:
| CPU: 3 UID: 0 PID: 166 Comm: cat Not tainted 6.13.0-rc2-00003-g3dafa7a7925d #2
| Hardware name: linux,dummy-virt (DT)
| pstate: 81400005 (Nzcv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
| pc : arch_stack_walk+0x1c8/0x370
| lr : arch_stack_walk+0x1b0/0x370
| sp : ffff800080773890
| x29: ffff800080773930 x28: fff0000005c44500 x27: fff00000058fa038
| x26: 000000007ffff000 x25: 0000000000000000 x24: 0000000000000000
| x23: ffffa35a8d9600ec x22: 0000000000000000 x21: fff00000043a33c0
| x20: ffff800080773970 x19: ffffa35a8d960168 x18: 0000000000000000
| x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
| x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000
| x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000
| x8 : ffff8000807738e0 x7 : ffff8000806e3800 x6 : ffff8000806e3818
| x5 : ffff800080773920 x4 : ffff8000806e4000 x3 : ffff8000807738e0
| x2 : 0000000000000018 x1 : ffff8000806e3800 x0 : 0000000000000000
| Call trace:
| arch_stack_walk+0x1c8/0x370 (P)
| stack_trace_save_tsk+0x8c/0x108
| proc_pid_stack+0xb0/0x134
| proc_single_show+0x60/0x120
| seq_read_iter+0x104/0x438
| seq_read+0xf8/0x140
| vfs_read+0xc4/0x31c
| ksys_read+0x70/0x108
| __arm64_sys_read+0x1c/0x28
| invoke_syscall+0x48/0x104
| el0_svc_common.constprop.0+0x40/0xe0
| do_el0_svc+0x1c/0x28
| el0_svc+0x30/0xcc
| el0t_64_sync_handler+0x10c/0x138
| el0t_64_sync+0x198/0x19c
| ---[ end trace 0000000000000000 ]---
Fix this by only warning when unwinding the current task. When unwinding
another task the error conditions will be handled by returning an error
without producing a warning.
The two warnings in kunwind_next_frame_record_meta() were added recently
as part of commit:
c2c6b27 ("arm64: stacktrace: unwind exception boundaries")
The warning when recovering the fgraph return address has changed form
many times, but was originally introduced back in commit:
9f41631 ("arm64: fix unwind_frame() for filtered out fn for function graph tracing")
Fixes: c2c6b27 ("arm64: stacktrace: unwind exception boundaries")
Fixes: 9f41631 ("arm64: fix unwind_frame() for filtered out fn for function graph tracing")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reported-by: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Kees Cook <keescook@chromium.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20241211140704.2498712-3-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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A "small" CIFS buffer is not big enough in general to hold a setacl request for SMB2, and we end up overflowing the buffer in send_set_info(). For instance: # mount.cifs //127.0.0.1/test /mnt/test -o username=test,password=test,nounix,cifsacl # touch /mnt/test/acltest # getcifsacl /mnt/test/acltest REVISION:0x1 CONTROL:0x9004 OWNER:S-1-5-21-2926364953-924364008-418108241-1000 GROUP:S-1-22-2-1001 ACL:S-1-5-21-2926364953-924364008-418108241-1000:ALLOWED/0x0/0x1e01ff ACL:S-1-22-2-1001:ALLOWED/0x0/R ACL:S-1-22-2-1001:ALLOWED/0x0/R ACL:S-1-5-21-2926364953-924364008-418108241-1000:ALLOWED/0x0/0x1e01ff ACL:S-1-1-0:ALLOWED/0x0/R # setcifsacl -a "ACL:S-1-22-2-1004:ALLOWED/0x0/R" /mnt/test/acltest this setacl will cause the following KASAN splat: [ 330.777927] BUG: KASAN: slab-out-of-bounds in send_set_info+0x4dd/0xc20 [cifs] [ 330.779696] Write of size 696 at addr ffff88010d5e2860 by task setcifsacl/1012 [ 330.781882] CPU: 1 PID: 1012 Comm: setcifsacl Not tainted 4.18.0-rc2+ #2 [ 330.783140] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 [ 330.784395] Call Trace: [ 330.784789] dump_stack+0xc2/0x16b [ 330.786777] print_address_description+0x6a/0x270 [ 330.787520] kasan_report+0x258/0x380 [ 330.788845] memcpy+0x34/0x50 [ 330.789369] send_set_info+0x4dd/0xc20 [cifs] [ 330.799511] SMB2_set_acl+0x76/0xa0 [cifs] [ 330.801395] set_smb2_acl+0x7ac/0xf30 [cifs] [ 330.830888] cifs_xattr_set+0x963/0xe40 [cifs] [ 330.840367] __vfs_setxattr+0x84/0xb0 [ 330.842060] __vfs_setxattr_noperm+0xe6/0x370 [ 330.843848] vfs_setxattr+0xc2/0xd0 [ 330.845519] setxattr+0x258/0x320 [ 330.859211] path_setxattr+0x15b/0x1b0 [ 330.864392] __x64_sys_setxattr+0xc0/0x160 [ 330.866133] do_syscall_64+0x14e/0x4b0 [ 330.876631] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 330.878503] RIP: 0033:0x7ff2e507db0a [ 330.880151] Code: 48 8b 0d 89 93 2c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 bc 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 56 93 2c 00 f7 d8 64 89 01 48 [ 330.885358] RSP: 002b:00007ffdc4903c18 EFLAGS: 00000246 ORIG_RAX: 00000000000000bc [ 330.887733] RAX: ffffffffffffffda RBX: 000055d1170de140 RCX: 00007ff2e507db0a [ 330.890067] RDX: 000055d1170de7d0 RSI: 000055d115b39184 RDI: 00007ffdc4904818 [ 330.892410] RBP: 0000000000000001 R08: 0000000000000000 R09: 000055d1170de7e4 [ 330.894785] R10: 00000000000002b8 R11: 0000000000000246 R12: 0000000000000007 [ 330.897148] R13: 000055d1170de0c0 R14: 0000000000000008 R15: 000055d1170de550 [ 330.901057] Allocated by task 1012: [ 330.902888] kasan_kmalloc+0xa0/0xd0 [ 330.904714] kmem_cache_alloc+0xc8/0x1d0 [ 330.906615] mempool_alloc+0x11e/0x380 [ 330.908496] cifs_small_buf_get+0x35/0x60 [cifs] [ 330.910510] smb2_plain_req_init+0x4a/0xd60 [cifs] [ 330.912551] send_set_info+0x198/0xc20 [cifs] [ 330.914535] SMB2_set_acl+0x76/0xa0 [cifs] [ 330.916465] set_smb2_acl+0x7ac/0xf30 [cifs] [ 330.918453] cifs_xattr_set+0x963/0xe40 [cifs] [ 330.920426] __vfs_setxattr+0x84/0xb0 [ 330.922284] __vfs_setxattr_noperm+0xe6/0x370 [ 330.924213] vfs_setxattr+0xc2/0xd0 [ 330.926008] setxattr+0x258/0x320 [ 330.927762] path_setxattr+0x15b/0x1b0 [ 330.929592] __x64_sys_setxattr+0xc0/0x160 [ 330.931459] do_syscall_64+0x14e/0x4b0 [ 330.933314] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 330.936843] Freed by task 0: [ 330.938588] (stack is not available) [ 330.941886] The buggy address belongs to the object at ffff88010d5e2800 which belongs to the cache cifs_small_rq of size 448 [ 330.946362] The buggy address is located 96 bytes inside of 448-byte region [ffff88010d5e2800, ffff88010d5e29c0) [ 330.950722] The buggy address belongs to the page: [ 330.952789] page:ffffea0004357880 count:1 mapcount:0 mapping:ffff880108fdca80 index:0x0 compound_mapcount: 0 [ 330.955665] flags: 0x17ffffc0008100(slab|head) [ 330.957760] raw: 0017ffffc0008100 dead000000000100 dead000000000200 ffff880108fdca80 [ 330.960356] raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 [ 330.963005] page dumped because: kasan: bad access detected [ 330.967039] Memory state around the buggy address: [ 330.969255] ffff88010d5e2880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 330.971833] ffff88010d5e2900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 330.974397] >ffff88010d5e2980: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc [ 330.976956] ^ [ 330.979226] ffff88010d5e2a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 330.981755] ffff88010d5e2a80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 330.984225] ================================================================== Fix this by allocating a regular CIFS buffer in smb2_plain_req_init() if the request command is SMB2_SET_INFO. Reported-by: Jianhong Yin <jiyin@redhat.com> Fixes: 366ed84 ("cifs: Use smb 2 - 3 and cifsacl mount options setacl function") CC: Stable <stable@vger.kernel.org> Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-and-tested-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Boris Protopopov <pboris@amazon.com>
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Jun 27, 2025
As reported by syzbot and experienced by Pavel, using cpus_read_lock() in wake_up_all_idle_cpus() generates lock inversion (against mmap_sem and possibly others). Instead, shrink the preempt disable region by iterating all CPUs and checking the online status for each individual CPU while having preemption disabled. Fixes: 8850cb6 ("sched: Simplify wake_up_*idle*()") Reported-by: syzbot+d5b23b18d2f4feae8a67@syzkaller.appspotmail.com Reported-by: Pavel Machek <pavel@ucw.cz> Reported-by: Qian Cai <quic_qiancai@quicinc.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Qian Cai <quic_qiancai@quicinc.com>
nathan-zcgao
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Jun 27, 2025
commit f79a609 upstream. log_max_qp in driver's default profile #2 was set to 18, but FW actually supports 17 at the most - a situation that led to the concerning print when the driver is loaded: "log_max_qp value in current profile is 18, changing to HCA capabaility limit (17)" The expected behavior from mlx5_profile #2 is to match the maximum FW capability in regards to log_max_qp. Thus, log_max_qp in profile #2 is initialized to a defined static value (0xff) - which basically means that when loading this profile, log_max_qp value will be what the currently installed FW supports at most. Signed-off-by: Maher Sanalla <msanalla@nvidia.com> Reviewed-by: Maor Gottlieb <maorg@nvidia.com> Signed-off-by: Saeed Mahameed <saeedm@nvidia.com> [v5.10: replaced prof->log_max_qp with profile[prof_sel].log_max_qp] Signed-off-by: Shaoying Xu <shaoyi@amazon.com>
nathan-zcgao
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Jun 27, 2025
As reported by syzbot and experienced by Pavel, using cpus_read_lock() in wake_up_all_idle_cpus() generates lock inversion (against mmap_sem and possibly others). Instead, shrink the preempt disable region by iterating all CPUs and checking the online status for each individual CPU while having preemption disabled. Fixes: 8850cb6 ("sched: Simplify wake_up_*idle*()") Reported-by: syzbot+d5b23b18d2f4feae8a67@syzkaller.appspotmail.com Reported-by: Pavel Machek <pavel@ucw.cz> Reported-by: Qian Cai <quic_qiancai@quicinc.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Qian Cai <quic_qiancai@quicinc.com>
nathan-zcgao
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Jun 27, 2025
commit f79a609 upstream. log_max_qp in driver's default profile #2 was set to 18, but FW actually supports 17 at the most - a situation that led to the concerning print when the driver is loaded: "log_max_qp value in current profile is 18, changing to HCA capabaility limit (17)" The expected behavior from mlx5_profile #2 is to match the maximum FW capability in regards to log_max_qp. Thus, log_max_qp in profile #2 is initialized to a defined static value (0xff) - which basically means that when loading this profile, log_max_qp value will be what the currently installed FW supports at most. Signed-off-by: Maher Sanalla <msanalla@nvidia.com> Reviewed-by: Maor Gottlieb <maorg@nvidia.com> Signed-off-by: Saeed Mahameed <saeedm@nvidia.com> [v5.10: replaced prof->log_max_qp with profile[prof_sel].log_max_qp] Signed-off-by: Shaoying Xu <shaoyi@amazon.com>
aahmed71
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Jun 28, 2025
A "small" CIFS buffer is not big enough in general to hold a setacl request for SMB2, and we end up overflowing the buffer in send_set_info(). For instance: # mount.cifs //127.0.0.1/test /mnt/test -o username=test,password=test,nounix,cifsacl # touch /mnt/test/acltest # getcifsacl /mnt/test/acltest REVISION:0x1 CONTROL:0x9004 OWNER:S-1-5-21-2926364953-924364008-418108241-1000 GROUP:S-1-22-2-1001 ACL:S-1-5-21-2926364953-924364008-418108241-1000:ALLOWED/0x0/0x1e01ff ACL:S-1-22-2-1001:ALLOWED/0x0/R ACL:S-1-22-2-1001:ALLOWED/0x0/R ACL:S-1-5-21-2926364953-924364008-418108241-1000:ALLOWED/0x0/0x1e01ff ACL:S-1-1-0:ALLOWED/0x0/R # setcifsacl -a "ACL:S-1-22-2-1004:ALLOWED/0x0/R" /mnt/test/acltest this setacl will cause the following KASAN splat: [ 330.777927] BUG: KASAN: slab-out-of-bounds in send_set_info+0x4dd/0xc20 [cifs] [ 330.779696] Write of size 696 at addr ffff88010d5e2860 by task setcifsacl/1012 [ 330.781882] CPU: 1 PID: 1012 Comm: setcifsacl Not tainted 4.18.0-rc2+ #2 [ 330.783140] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 [ 330.784395] Call Trace: [ 330.784789] dump_stack+0xc2/0x16b [ 330.786777] print_address_description+0x6a/0x270 [ 330.787520] kasan_report+0x258/0x380 [ 330.788845] memcpy+0x34/0x50 [ 330.789369] send_set_info+0x4dd/0xc20 [cifs] [ 330.799511] SMB2_set_acl+0x76/0xa0 [cifs] [ 330.801395] set_smb2_acl+0x7ac/0xf30 [cifs] [ 330.830888] cifs_xattr_set+0x963/0xe40 [cifs] [ 330.840367] __vfs_setxattr+0x84/0xb0 [ 330.842060] __vfs_setxattr_noperm+0xe6/0x370 [ 330.843848] vfs_setxattr+0xc2/0xd0 [ 330.845519] setxattr+0x258/0x320 [ 330.859211] path_setxattr+0x15b/0x1b0 [ 330.864392] __x64_sys_setxattr+0xc0/0x160 [ 330.866133] do_syscall_64+0x14e/0x4b0 [ 330.876631] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 330.878503] RIP: 0033:0x7ff2e507db0a [ 330.880151] Code: 48 8b 0d 89 93 2c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 bc 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 56 93 2c 00 f7 d8 64 89 01 48 [ 330.885358] RSP: 002b:00007ffdc4903c18 EFLAGS: 00000246 ORIG_RAX: 00000000000000bc [ 330.887733] RAX: ffffffffffffffda RBX: 000055d1170de140 RCX: 00007ff2e507db0a [ 330.890067] RDX: 000055d1170de7d0 RSI: 000055d115b39184 RDI: 00007ffdc4904818 [ 330.892410] RBP: 0000000000000001 R08: 0000000000000000 R09: 000055d1170de7e4 [ 330.894785] R10: 00000000000002b8 R11: 0000000000000246 R12: 0000000000000007 [ 330.897148] R13: 000055d1170de0c0 R14: 0000000000000008 R15: 000055d1170de550 [ 330.901057] Allocated by task 1012: [ 330.902888] kasan_kmalloc+0xa0/0xd0 [ 330.904714] kmem_cache_alloc+0xc8/0x1d0 [ 330.906615] mempool_alloc+0x11e/0x380 [ 330.908496] cifs_small_buf_get+0x35/0x60 [cifs] [ 330.910510] smb2_plain_req_init+0x4a/0xd60 [cifs] [ 330.912551] send_set_info+0x198/0xc20 [cifs] [ 330.914535] SMB2_set_acl+0x76/0xa0 [cifs] [ 330.916465] set_smb2_acl+0x7ac/0xf30 [cifs] [ 330.918453] cifs_xattr_set+0x963/0xe40 [cifs] [ 330.920426] __vfs_setxattr+0x84/0xb0 [ 330.922284] __vfs_setxattr_noperm+0xe6/0x370 [ 330.924213] vfs_setxattr+0xc2/0xd0 [ 330.926008] setxattr+0x258/0x320 [ 330.927762] path_setxattr+0x15b/0x1b0 [ 330.929592] __x64_sys_setxattr+0xc0/0x160 [ 330.931459] do_syscall_64+0x14e/0x4b0 [ 330.933314] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 330.936843] Freed by task 0: [ 330.938588] (stack is not available) [ 330.941886] The buggy address belongs to the object at ffff88010d5e2800 which belongs to the cache cifs_small_rq of size 448 [ 330.946362] The buggy address is located 96 bytes inside of 448-byte region [ffff88010d5e2800, ffff88010d5e29c0) [ 330.950722] The buggy address belongs to the page: [ 330.952789] page:ffffea0004357880 count:1 mapcount:0 mapping:ffff880108fdca80 index:0x0 compound_mapcount: 0 [ 330.955665] flags: 0x17ffffc0008100(slab|head) [ 330.957760] raw: 0017ffffc0008100 dead000000000100 dead000000000200 ffff880108fdca80 [ 330.960356] raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 [ 330.963005] page dumped because: kasan: bad access detected [ 330.967039] Memory state around the buggy address: [ 330.969255] ffff88010d5e2880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 330.971833] ffff88010d5e2900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 330.974397] >ffff88010d5e2980: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc [ 330.976956] ^ [ 330.979226] ffff88010d5e2a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 330.981755] ffff88010d5e2a80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 330.984225] ================================================================== Fix this by allocating a regular CIFS buffer in smb2_plain_req_init() if the request command is SMB2_SET_INFO. Reported-by: Jianhong Yin <jiyin@redhat.com> Fixes: 366ed84 ("cifs: Use smb 2 - 3 and cifsacl mount options setacl function") CC: Stable <stable@vger.kernel.org> Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-and-tested-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Boris Protopopov <pboris@amazon.com>
paniakin-aws
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Jun 28, 2025
The WARN_ON_ONCE is introduced on truncate_folio_batch_exceptionals() to capture whether the filesystem has removed all DAX entries or not. And the fix has been applied on the filesystem xfs and ext4 by the commit 0e2f80a ("fs/dax: ensure all pages are idle prior to filesystem unmount"). Apply the missed fix on filesystem fuse to fix the runtime warning: [ 2.011450] ------------[ cut here ]------------ [ 2.011873] WARNING: CPU: 0 PID: 145 at mm/truncate.c:89 truncate_folio_batch_exceptionals+0x272/0x2b0 [ 2.012468] Modules linked in: [ 2.012718] CPU: 0 UID: 1000 PID: 145 Comm: weston Not tainted 6.16.0-rc2-WSL2-STABLE #2 PREEMPT(undef) [ 2.013292] RIP: 0010:truncate_folio_batch_exceptionals+0x272/0x2b0 [ 2.013704] Code: 48 63 d0 41 29 c5 48 8d 1c d5 00 00 00 00 4e 8d 6c 2a 01 49 c1 e5 03 eb 09 48 83 c3 08 49 39 dd 74 83 41 f6 44 1c 08 01 74 ef <0f> 0b 49 8b 34 1e 48 89 ef e8 10 a2 17 00 eb df 48 8b 7d 00 e8 35 [ 2.014845] RSP: 0018:ffffa47ec33f3b10 EFLAGS: 00010202 [ 2.015279] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 2.015884] RDX: 0000000000000000 RSI: ffffa47ec33f3ca0 RDI: ffff98aa44f3fa80 [ 2.016377] RBP: ffff98aa44f3fbf0 R08: ffffa47ec33f3ba8 R09: 0000000000000000 [ 2.016942] R10: 0000000000000001 R11: 0000000000000000 R12: ffffa47ec33f3ca0 [ 2.017437] R13: 0000000000000008 R14: ffffa47ec33f3ba8 R15: 0000000000000000 [ 2.017972] FS: 000079ce006afa40(0000) GS:ffff98aade441000(0000) knlGS:0000000000000000 [ 2.018510] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 2.018987] CR2: 000079ce03e74000 CR3: 000000010784f006 CR4: 0000000000372eb0 [ 2.019518] Call Trace: [ 2.019729] <TASK> [ 2.019901] truncate_inode_pages_range+0xd8/0x400 [ 2.020280] ? timerqueue_add+0x66/0xb0 [ 2.020574] ? get_nohz_timer_target+0x2a/0x140 [ 2.020904] ? timerqueue_add+0x66/0xb0 [ 2.021231] ? timerqueue_del+0x2e/0x50 [ 2.021646] ? __remove_hrtimer+0x39/0x90 [ 2.022017] ? srso_alias_untrain_ret+0x1/0x10 [ 2.022497] ? psi_group_change+0x136/0x350 [ 2.023046] ? _raw_spin_unlock+0xe/0x30 [ 2.023514] ? finish_task_switch.isra.0+0x8d/0x280 [ 2.024068] ? __schedule+0x532/0xbd0 [ 2.024551] fuse_evict_inode+0x29/0x190 [ 2.025131] evict+0x100/0x270 [ 2.025641] ? _atomic_dec_and_lock+0x39/0x50 [ 2.026316] ? __pfx_generic_delete_inode+0x10/0x10 [ 2.026843] __dentry_kill+0x71/0x180 [ 2.027335] dput+0xeb/0x1b0 [ 2.027725] __fput+0x136/0x2b0 [ 2.028054] __x64_sys_close+0x3d/0x80 [ 2.028469] do_syscall_64+0x6d/0x1b0 [ 2.028832] ? clear_bhb_loop+0x30/0x80 [ 2.029182] ? clear_bhb_loop+0x30/0x80 [ 2.029533] ? clear_bhb_loop+0x30/0x80 [ 2.029902] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 2.030423] RIP: 0033:0x79ce03d0d067 [ 2.030820] Code: b8 ff ff ff ff e9 3e ff ff ff 66 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 41 c3 48 83 ec 18 89 7c 24 0c e8 c3 a7 f8 ff [ 2.032354] RSP: 002b:00007ffef0498948 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 [ 2.032939] RAX: ffffffffffffffda RBX: 00007ffef0498960 RCX: 000079ce03d0d067 [ 2.033612] RDX: 0000000000000003 RSI: 0000000000001000 RDI: 000000000000000d [ 2.034289] RBP: 00007ffef0498a30 R08: 000000000000000d R09: 0000000000000000 [ 2.034944] R10: 00007ffef0498978 R11: 0000000000000246 R12: 0000000000000001 [ 2.035610] R13: 00007ffef0498960 R14: 000079ce03e09ce0 R15: 0000000000000003 [ 2.036301] </TASK> [ 2.036532] ---[ end trace 0000000000000000 ]--- Link: https://lkml.kernel.org/r/20250621171507.3770-1-haiyuewa@163.com Fixes: bde708f ("fs/dax: always remove DAX page-cache entries when breaking layouts") Signed-off-by: Haiyue Wang <haiyuewa@163.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
paniakin-aws
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Jun 28, 2025
Fix cifs_signal_cifsd_for_reconnect() to take the correct lock order
and prevent the following deadlock from happening
======================================================
WARNING: possible circular locking dependency detected
6.16.0-rc3-build2+ #1301 Tainted: G S W
------------------------------------------------------
cifsd/6055 is trying to acquire lock:
ffff88810ad56038 (&tcp_ses->srv_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0x134/0x200
but task is already holding lock:
ffff888119c64330 (&ret_buf->chan_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0xcf/0x200
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&ret_buf->chan_lock){+.+.}-{3:3}:
validate_chain+0x1cf/0x270
__lock_acquire+0x60e/0x780
lock_acquire.part.0+0xb4/0x1f0
_raw_spin_lock+0x2f/0x40
cifs_setup_session+0x81/0x4b0
cifs_get_smb_ses+0x771/0x900
cifs_mount_get_session+0x7e/0x170
cifs_mount+0x92/0x2d0
cifs_smb3_do_mount+0x161/0x460
smb3_get_tree+0x55/0x90
vfs_get_tree+0x46/0x180
do_new_mount+0x1b0/0x2e0
path_mount+0x6ee/0x740
do_mount+0x98/0xe0
__do_sys_mount+0x148/0x180
do_syscall_64+0xa4/0x260
entry_SYSCALL_64_after_hwframe+0x76/0x7e
-> #1 (&ret_buf->ses_lock){+.+.}-{3:3}:
validate_chain+0x1cf/0x270
__lock_acquire+0x60e/0x780
lock_acquire.part.0+0xb4/0x1f0
_raw_spin_lock+0x2f/0x40
cifs_match_super+0x101/0x320
sget+0xab/0x270
cifs_smb3_do_mount+0x1e0/0x460
smb3_get_tree+0x55/0x90
vfs_get_tree+0x46/0x180
do_new_mount+0x1b0/0x2e0
path_mount+0x6ee/0x740
do_mount+0x98/0xe0
__do_sys_mount+0x148/0x180
do_syscall_64+0xa4/0x260
entry_SYSCALL_64_after_hwframe+0x76/0x7e
-> #0 (&tcp_ses->srv_lock){+.+.}-{3:3}:
check_noncircular+0x95/0xc0
check_prev_add+0x115/0x2f0
validate_chain+0x1cf/0x270
__lock_acquire+0x60e/0x780
lock_acquire.part.0+0xb4/0x1f0
_raw_spin_lock+0x2f/0x40
cifs_signal_cifsd_for_reconnect+0x134/0x200
__cifs_reconnect+0x8f/0x500
cifs_handle_standard+0x112/0x280
cifs_demultiplex_thread+0x64d/0xbc0
kthread+0x2f7/0x310
ret_from_fork+0x2a/0x230
ret_from_fork_asm+0x1a/0x30
other info that might help us debug this:
Chain exists of:
&tcp_ses->srv_lock --> &ret_buf->ses_lock --> &ret_buf->chan_lock
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&ret_buf->chan_lock);
lock(&ret_buf->ses_lock);
lock(&ret_buf->chan_lock);
lock(&tcp_ses->srv_lock);
*** DEADLOCK ***
3 locks held by cifsd/6055:
#0: ffffffff857de398 (&cifs_tcp_ses_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0x7b/0x200
#1: ffff888119c64060 (&ret_buf->ses_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0x9c/0x200
#2: ffff888119c64330 (&ret_buf->chan_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0xcf/0x200
Cc: linux-cifs@vger.kernel.org
Reported-by: David Howells <dhowells@redhat.com>
Fixes: d7d7a66 ("cifs: avoid use of global locks for high contention data")
Reviewed-by: David Howells <dhowells@redhat.com>
Tested-by: David Howells <dhowells@redhat.com>
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
aahmed71
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Jul 1, 2025
commit 96611c2 upstream. As reported by syzbot and experienced by Pavel, using cpus_read_lock() in wake_up_all_idle_cpus() generates lock inversion (against mmap_sem and possibly others). Instead, shrink the preempt disable region by iterating all CPUs and checking the online status for each individual CPU while having preemption disabled. Fixes: 8850cb6 ("sched: Simplify wake_up_*idle*()") Reported-by: syzbot+d5b23b18d2f4feae8a67@syzkaller.appspotmail.com Reported-by: Pavel Machek <pavel@ucw.cz> Reported-by: Qian Cai <quic_qiancai@quicinc.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Qian Cai <quic_qiancai@quicinc.com> (cherry picked from commit 96611c2)
shaoyingxu
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Jul 1, 2025
Aishwarya reports that warnings are sometimes seen when running the ftrace kselftests, e.g. | WARNING: CPU: 5 PID: 2066 at arch/arm64/kernel/stacktrace.c:141 arch_stack_walk+0x4a0/0x4c0 | Modules linked in: | CPU: 5 UID: 0 PID: 2066 Comm: ftracetest Not tainted 6.13.0-rc2 #2 | Hardware name: linux,dummy-virt (DT) | pstate: 604000c5 (nZCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--) | pc : arch_stack_walk+0x4a0/0x4c0 | lr : arch_stack_walk+0x248/0x4c0 | sp : ffff800083643d20 | x29: ffff800083643dd0 x28: ffff00007b891400 x27: ffff00007b891928 | x26: 0000000000000001 x25: 00000000000000c0 x24: ffff800082f39d80 | x23: ffff80008003ee8c x22: ffff80008004baa8 x21: ffff8000800533e0 | x20: ffff800083643e10 x19: ffff80008003eec8 x18: 0000000000000000 | x17: 0000000000000000 x16: ffff800083640000 x15: 0000000000000000 | x14: 02a37a802bbb8a92 x13: 00000000000001a9 x12: 0000000000000001 | x11: ffff800082ffad60 x10: ffff800083643d20 x9 : ffff80008003eed0 | x8 : ffff80008004baa8 x7 : ffff800086f2be80 x6 : ffff0000057cf000 | x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff800086f2b690 | x2 : ffff80008004baa8 x1 : ffff80008004baa8 x0 : ffff80008004baa8 | Call trace: | arch_stack_walk+0x4a0/0x4c0 (P) | arch_stack_walk+0x248/0x4c0 (L) | profile_pc+0x44/0x80 | profile_tick+0x50/0x80 (F) | tick_nohz_handler+0xcc/0x160 (F) | __hrtimer_run_queues+0x2ac/0x340 (F) | hrtimer_interrupt+0xf4/0x268 (F) | arch_timer_handler_virt+0x34/0x60 (F) | handle_percpu_devid_irq+0x88/0x220 (F) | generic_handle_domain_irq+0x34/0x60 (F) | gic_handle_irq+0x54/0x140 (F) | call_on_irq_stack+0x24/0x58 (F) | do_interrupt_handler+0x88/0x98 | el1_interrupt+0x34/0x68 (F) | el1h_64_irq_handler+0x18/0x28 | el1h_64_irq+0x6c/0x70 | queued_spin_lock_slowpath+0x78/0x460 (P) The warning in question is: WARN_ON_ONCE(state->common.pc == orig_pc)) ... in kunwind_recover_return_address(), which is triggered when return_to_handler() is encountered in the trace, but ftrace_graph_ret_addr() cannot find a corresponding original return address on the fgraph return stack. This happens because the stacktrace code encounters an exception boundary where the LR was not live at the time of the exception, but the LR happens to contain return_to_handler(); either because the task recently returned there, or due to unfortunate usage of the LR at a scratch register. In such cases attempts to recover the return address via ftrace_graph_ret_addr() may fail, triggering the WARN_ON_ONCE() above and aborting the unwind (hence the stacktrace terminating after reporting the PC at the time of the exception). Handling unreliable LR values in these cases is likely to require some larger rework, so for the moment avoid this problem by restoring the old behaviour of skipping the LR at exception boundaries, which the stacktrace code did prior to commit: c2c6b27 ("arm64: stacktrace: unwind exception boundaries") This commit is effectively a partial revert, keeping the structures and logic to explicitly identify exception boundaries while still skipping reporting of the LR. The logic to explicitly identify exception boundaries is still useful for general robustness and as a building block for future support for RELIABLE_STACKTRACE. Fixes: c2c6b27 ("arm64: stacktrace: unwind exception boundaries") Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reported-by: Aishwarya TCV <aishwarya.tcv@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20241211140704.2498712-2-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
shaoyingxu
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Jul 1, 2025
The arm64 stacktrace code has a few error conditions where a
WARN_ON_ONCE() is triggered before the stacktrace is terminated and an
error is returned to the caller. The conditions shouldn't be triggered
when unwinding the current task, but it is possible to trigger these
when unwinding another task which is not blocked, as the stack of that
task is concurrently modified. Kent reports that these warnings can be
triggered while running filesystem tests on bcachefs, which calls the
stacktrace code directly.
To produce a meaningful stacktrace of another task, the task in question
should be blocked, but the stacktrace code is expected to be robust to
cases where it is not blocked. Note that this is purely about not
unuduly scaring the user and/or crashing the kernel; stacktraces in such
cases are meaningless and may leak kernel secrets from the stack of the
task being unwound.
Ideally we'd pin the task in a blocked state during the unwind, as we do
for /proc/${PID}/wchan since commit:
42a20f8 ("sched: Add wrapper for get_wchan() to keep task blocked")
... but a bunch of places don't do that, notably /proc/${PID}/stack,
where we don't pin the task in a blocked state, but do restrict the
output to privileged users since commit:
f8a00ce ("proc: restrict kernel stack dumps to root")
... and so it's possible to trigger these warnings accidentally, e.g. by
reading /proc/*/stack (as root):
| for n in $(seq 1 10); do
| while true; do cat /proc/*/stack > /dev/null 2>&1; done &
| done
| ------------[ cut here ]------------
| WARNING: CPU: 3 PID: 166 at arch/arm64/kernel/stacktrace.c:207 arch_stack_walk+0x1c8/0x370
| Modules linked in:
| CPU: 3 UID: 0 PID: 166 Comm: cat Not tainted 6.13.0-rc2-00003-g3dafa7a7925d #2
| Hardware name: linux,dummy-virt (DT)
| pstate: 81400005 (Nzcv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
| pc : arch_stack_walk+0x1c8/0x370
| lr : arch_stack_walk+0x1b0/0x370
| sp : ffff800080773890
| x29: ffff800080773930 x28: fff0000005c44500 x27: fff00000058fa038
| x26: 000000007ffff000 x25: 0000000000000000 x24: 0000000000000000
| x23: ffffa35a8d9600ec x22: 0000000000000000 x21: fff00000043a33c0
| x20: ffff800080773970 x19: ffffa35a8d960168 x18: 0000000000000000
| x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
| x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000
| x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000
| x8 : ffff8000807738e0 x7 : ffff8000806e3800 x6 : ffff8000806e3818
| x5 : ffff800080773920 x4 : ffff8000806e4000 x3 : ffff8000807738e0
| x2 : 0000000000000018 x1 : ffff8000806e3800 x0 : 0000000000000000
| Call trace:
| arch_stack_walk+0x1c8/0x370 (P)
| stack_trace_save_tsk+0x8c/0x108
| proc_pid_stack+0xb0/0x134
| proc_single_show+0x60/0x120
| seq_read_iter+0x104/0x438
| seq_read+0xf8/0x140
| vfs_read+0xc4/0x31c
| ksys_read+0x70/0x108
| __arm64_sys_read+0x1c/0x28
| invoke_syscall+0x48/0x104
| el0_svc_common.constprop.0+0x40/0xe0
| do_el0_svc+0x1c/0x28
| el0_svc+0x30/0xcc
| el0t_64_sync_handler+0x10c/0x138
| el0t_64_sync+0x198/0x19c
| ---[ end trace 0000000000000000 ]---
Fix this by only warning when unwinding the current task. When unwinding
another task the error conditions will be handled by returning an error
without producing a warning.
The two warnings in kunwind_next_frame_record_meta() were added recently
as part of commit:
c2c6b27 ("arm64: stacktrace: unwind exception boundaries")
The warning when recovering the fgraph return address has changed form
many times, but was originally introduced back in commit:
9f41631 ("arm64: fix unwind_frame() for filtered out fn for function graph tracing")
Fixes: c2c6b27 ("arm64: stacktrace: unwind exception boundaries")
Fixes: 9f41631 ("arm64: fix unwind_frame() for filtered out fn for function graph tracing")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reported-by: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Kees Cook <keescook@chromium.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20241211140704.2498712-3-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
aahmed71
pushed a commit
that referenced
this pull request
Jul 1, 2025
commit 96611c2 upstream. As reported by syzbot and experienced by Pavel, using cpus_read_lock() in wake_up_all_idle_cpus() generates lock inversion (against mmap_sem and possibly others). Instead, shrink the preempt disable region by iterating all CPUs and checking the online status for each individual CPU while having preemption disabled. Fixes: 8850cb6 ("sched: Simplify wake_up_*idle*()") Reported-by: syzbot+d5b23b18d2f4feae8a67@syzkaller.appspotmail.com Reported-by: Pavel Machek <pavel@ucw.cz> Reported-by: Qian Cai <quic_qiancai@quicinc.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Qian Cai <quic_qiancai@quicinc.com> (cherry picked from commit 96611c2)
heynemax
pushed a commit
that referenced
this pull request
Jul 1, 2025
Aishwarya reports that warnings are sometimes seen when running the ftrace kselftests, e.g. | WARNING: CPU: 5 PID: 2066 at arch/arm64/kernel/stacktrace.c:141 arch_stack_walk+0x4a0/0x4c0 | Modules linked in: | CPU: 5 UID: 0 PID: 2066 Comm: ftracetest Not tainted 6.13.0-rc2 #2 | Hardware name: linux,dummy-virt (DT) | pstate: 604000c5 (nZCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--) | pc : arch_stack_walk+0x4a0/0x4c0 | lr : arch_stack_walk+0x248/0x4c0 | sp : ffff800083643d20 | x29: ffff800083643dd0 x28: ffff00007b891400 x27: ffff00007b891928 | x26: 0000000000000001 x25: 00000000000000c0 x24: ffff800082f39d80 | x23: ffff80008003ee8c x22: ffff80008004baa8 x21: ffff8000800533e0 | x20: ffff800083643e10 x19: ffff80008003eec8 x18: 0000000000000000 | x17: 0000000000000000 x16: ffff800083640000 x15: 0000000000000000 | x14: 02a37a802bbb8a92 x13: 00000000000001a9 x12: 0000000000000001 | x11: ffff800082ffad60 x10: ffff800083643d20 x9 : ffff80008003eed0 | x8 : ffff80008004baa8 x7 : ffff800086f2be80 x6 : ffff0000057cf000 | x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff800086f2b690 | x2 : ffff80008004baa8 x1 : ffff80008004baa8 x0 : ffff80008004baa8 | Call trace: | arch_stack_walk+0x4a0/0x4c0 (P) | arch_stack_walk+0x248/0x4c0 (L) | profile_pc+0x44/0x80 | profile_tick+0x50/0x80 (F) | tick_nohz_handler+0xcc/0x160 (F) | __hrtimer_run_queues+0x2ac/0x340 (F) | hrtimer_interrupt+0xf4/0x268 (F) | arch_timer_handler_virt+0x34/0x60 (F) | handle_percpu_devid_irq+0x88/0x220 (F) | generic_handle_domain_irq+0x34/0x60 (F) | gic_handle_irq+0x54/0x140 (F) | call_on_irq_stack+0x24/0x58 (F) | do_interrupt_handler+0x88/0x98 | el1_interrupt+0x34/0x68 (F) | el1h_64_irq_handler+0x18/0x28 | el1h_64_irq+0x6c/0x70 | queued_spin_lock_slowpath+0x78/0x460 (P) The warning in question is: WARN_ON_ONCE(state->common.pc == orig_pc)) ... in kunwind_recover_return_address(), which is triggered when return_to_handler() is encountered in the trace, but ftrace_graph_ret_addr() cannot find a corresponding original return address on the fgraph return stack. This happens because the stacktrace code encounters an exception boundary where the LR was not live at the time of the exception, but the LR happens to contain return_to_handler(); either because the task recently returned there, or due to unfortunate usage of the LR at a scratch register. In such cases attempts to recover the return address via ftrace_graph_ret_addr() may fail, triggering the WARN_ON_ONCE() above and aborting the unwind (hence the stacktrace terminating after reporting the PC at the time of the exception). Handling unreliable LR values in these cases is likely to require some larger rework, so for the moment avoid this problem by restoring the old behaviour of skipping the LR at exception boundaries, which the stacktrace code did prior to commit: c2c6b27 ("arm64: stacktrace: unwind exception boundaries") This commit is effectively a partial revert, keeping the structures and logic to explicitly identify exception boundaries while still skipping reporting of the LR. The logic to explicitly identify exception boundaries is still useful for general robustness and as a building block for future support for RELIABLE_STACKTRACE. Fixes: c2c6b27 ("arm64: stacktrace: unwind exception boundaries") Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reported-by: Aishwarya TCV <aishwarya.tcv@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20241211140704.2498712-2-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
heynemax
pushed a commit
that referenced
this pull request
Jul 1, 2025
The arm64 stacktrace code has a few error conditions where a
WARN_ON_ONCE() is triggered before the stacktrace is terminated and an
error is returned to the caller. The conditions shouldn't be triggered
when unwinding the current task, but it is possible to trigger these
when unwinding another task which is not blocked, as the stack of that
task is concurrently modified. Kent reports that these warnings can be
triggered while running filesystem tests on bcachefs, which calls the
stacktrace code directly.
To produce a meaningful stacktrace of another task, the task in question
should be blocked, but the stacktrace code is expected to be robust to
cases where it is not blocked. Note that this is purely about not
unuduly scaring the user and/or crashing the kernel; stacktraces in such
cases are meaningless and may leak kernel secrets from the stack of the
task being unwound.
Ideally we'd pin the task in a blocked state during the unwind, as we do
for /proc/${PID}/wchan since commit:
42a20f8 ("sched: Add wrapper for get_wchan() to keep task blocked")
... but a bunch of places don't do that, notably /proc/${PID}/stack,
where we don't pin the task in a blocked state, but do restrict the
output to privileged users since commit:
f8a00ce ("proc: restrict kernel stack dumps to root")
... and so it's possible to trigger these warnings accidentally, e.g. by
reading /proc/*/stack (as root):
| for n in $(seq 1 10); do
| while true; do cat /proc/*/stack > /dev/null 2>&1; done &
| done
| ------------[ cut here ]------------
| WARNING: CPU: 3 PID: 166 at arch/arm64/kernel/stacktrace.c:207 arch_stack_walk+0x1c8/0x370
| Modules linked in:
| CPU: 3 UID: 0 PID: 166 Comm: cat Not tainted 6.13.0-rc2-00003-g3dafa7a7925d #2
| Hardware name: linux,dummy-virt (DT)
| pstate: 81400005 (Nzcv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
| pc : arch_stack_walk+0x1c8/0x370
| lr : arch_stack_walk+0x1b0/0x370
| sp : ffff800080773890
| x29: ffff800080773930 x28: fff0000005c44500 x27: fff00000058fa038
| x26: 000000007ffff000 x25: 0000000000000000 x24: 0000000000000000
| x23: ffffa35a8d9600ec x22: 0000000000000000 x21: fff00000043a33c0
| x20: ffff800080773970 x19: ffffa35a8d960168 x18: 0000000000000000
| x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
| x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000
| x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000
| x8 : ffff8000807738e0 x7 : ffff8000806e3800 x6 : ffff8000806e3818
| x5 : ffff800080773920 x4 : ffff8000806e4000 x3 : ffff8000807738e0
| x2 : 0000000000000018 x1 : ffff8000806e3800 x0 : 0000000000000000
| Call trace:
| arch_stack_walk+0x1c8/0x370 (P)
| stack_trace_save_tsk+0x8c/0x108
| proc_pid_stack+0xb0/0x134
| proc_single_show+0x60/0x120
| seq_read_iter+0x104/0x438
| seq_read+0xf8/0x140
| vfs_read+0xc4/0x31c
| ksys_read+0x70/0x108
| __arm64_sys_read+0x1c/0x28
| invoke_syscall+0x48/0x104
| el0_svc_common.constprop.0+0x40/0xe0
| do_el0_svc+0x1c/0x28
| el0_svc+0x30/0xcc
| el0t_64_sync_handler+0x10c/0x138
| el0t_64_sync+0x198/0x19c
| ---[ end trace 0000000000000000 ]---
Fix this by only warning when unwinding the current task. When unwinding
another task the error conditions will be handled by returning an error
without producing a warning.
The two warnings in kunwind_next_frame_record_meta() were added recently
as part of commit:
c2c6b27 ("arm64: stacktrace: unwind exception boundaries")
The warning when recovering the fgraph return address has changed form
many times, but was originally introduced back in commit:
9f41631 ("arm64: fix unwind_frame() for filtered out fn for function graph tracing")
Fixes: c2c6b27 ("arm64: stacktrace: unwind exception boundaries")
Fixes: 9f41631 ("arm64: fix unwind_frame() for filtered out fn for function graph tracing")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reported-by: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Kees Cook <keescook@chromium.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20241211140704.2498712-3-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
paniakin-aws
pushed a commit
that referenced
this pull request
Jul 1, 2025
As reported by syzbot and experienced by Pavel, using cpus_read_lock() in wake_up_all_idle_cpus() generates lock inversion (against mmap_sem and possibly others). Instead, shrink the preempt disable region by iterating all CPUs and checking the online status for each individual CPU while having preemption disabled. Fixes: 8850cb6 ("sched: Simplify wake_up_*idle*()") Reported-by: syzbot+d5b23b18d2f4feae8a67@syzkaller.appspotmail.com Reported-by: Pavel Machek <pavel@ucw.cz> Reported-by: Qian Cai <quic_qiancai@quicinc.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Qian Cai <quic_qiancai@quicinc.com>
paniakin-aws
pushed a commit
that referenced
this pull request
Jul 1, 2025
commit f79a609 upstream. log_max_qp in driver's default profile #2 was set to 18, but FW actually supports 17 at the most - a situation that led to the concerning print when the driver is loaded: "log_max_qp value in current profile is 18, changing to HCA capabaility limit (17)" The expected behavior from mlx5_profile #2 is to match the maximum FW capability in regards to log_max_qp. Thus, log_max_qp in profile #2 is initialized to a defined static value (0xff) - which basically means that when loading this profile, log_max_qp value will be what the currently installed FW supports at most. Signed-off-by: Maher Sanalla <msanalla@nvidia.com> Reviewed-by: Maor Gottlieb <maorg@nvidia.com> Signed-off-by: Saeed Mahameed <saeedm@nvidia.com> [v5.10: replaced prof->log_max_qp with profile[prof_sel].log_max_qp] Signed-off-by: Shaoying Xu <shaoyi@amazon.com>
paniakin-aws
pushed a commit
that referenced
this pull request
Jul 1, 2025
As reported by syzbot and experienced by Pavel, using cpus_read_lock() in wake_up_all_idle_cpus() generates lock inversion (against mmap_sem and possibly others). Instead, shrink the preempt disable region by iterating all CPUs and checking the online status for each individual CPU while having preemption disabled. Fixes: 8850cb6 ("sched: Simplify wake_up_*idle*()") Reported-by: syzbot+d5b23b18d2f4feae8a67@syzkaller.appspotmail.com Reported-by: Pavel Machek <pavel@ucw.cz> Reported-by: Qian Cai <quic_qiancai@quicinc.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Qian Cai <quic_qiancai@quicinc.com>
paniakin-aws
pushed a commit
that referenced
this pull request
Jul 1, 2025
commit f79a609 upstream. log_max_qp in driver's default profile #2 was set to 18, but FW actually supports 17 at the most - a situation that led to the concerning print when the driver is loaded: "log_max_qp value in current profile is 18, changing to HCA capabaility limit (17)" The expected behavior from mlx5_profile #2 is to match the maximum FW capability in regards to log_max_qp. Thus, log_max_qp in profile #2 is initialized to a defined static value (0xff) - which basically means that when loading this profile, log_max_qp value will be what the currently installed FW supports at most. Signed-off-by: Maher Sanalla <msanalla@nvidia.com> Reviewed-by: Maor Gottlieb <maorg@nvidia.com> Signed-off-by: Saeed Mahameed <saeedm@nvidia.com> [v5.10: replaced prof->log_max_qp with profile[prof_sel].log_max_qp] Signed-off-by: Shaoying Xu <shaoyi@amazon.com>
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Issue #, if available:
vewe-richard#1
Description of changes:
Do not call generic_file_buffered_read() directly, call generic_file_read_iter() which will check number of iov to read, and return immediately when the number of iov is zero.
Else, generic_file_buffered_read() will fall into an infinite loop, eat up all cpu resources, cause system lockup.