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Hello @gregkh

I don't know if you use github for pull requests. Let's give it a try ;)

Dan Carpenter and others added 16 commits March 4, 2020 21:23
…ime()

This function is called from load_guspatch() and the rate is specified
by the user.  If they accidentally selected zero then it would crash the
kernel.  I've just changed the zero to a one.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
of_find_node_by_path() acquires a reference to the node
returned by it and that reference needs to be dropped by its caller.
This place doesn't do that, so fix it.

Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
make sure that info->node is initialized early, so that kernfs_kill_sb()
can list_del() it safely.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
A controller reset after a run time change of the CMB module parameter
breaks the driver. An 'on -> off' will have the driver use NULL for the
host memory queue, and 'off -> on' will use mismatched queue depth between
the device and the host.

We could fix both, but there isn't really a good reason to change this
at run time anyway, compared to at module load time, so this patch makes
parameter read-only after after modprobe.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
There is no need to print a backtrace if kzalloc() fails, as the memory
allocation core already takes care of that.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rob Herring <robh@kernel.org>
KMSAN will complain if valid address length passed to bind()/connect()/
sendmsg() is shorter than sizeof("struct sockaddr"->sa_family) bytes.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jamorris@linux.microsoft.com>
There is a potential NULL pointer dereference in case
fb_create_modedb() fails and returns NULL.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Rob Herring <robh@kernel.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
The FQ implementation used by mac80211 allocates memory using kmalloc(),
which can fail; and Johannes reported that this actually happens in
practice.

To avoid this, switch the allocation to kvmalloc() instead; this also
brings fq_impl in line with all the FQ qdiscs.

Fixes: 557fc4a ("fq: add fair queuing framework")
Reported-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/20191105155750.547379-1-toke@redhat.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
SOMAXCONN is /proc/sys/net/core/somaxconn default value.

It has been defined as 128 more than 20 years ago.

Since it caps the listen() backlog values, the very small value has
caused numerous problems over the years, and many people had
to raise it on their hosts after beeing hit by problems.

Google has been using 1024 for at least 15 years, and we increased
this to 4096 after TCP listener rework has been completed, more than
4 years ago. We got no complain of this change breaking any
legacy application.

Many applications indeed setup a TCP listener with listen(fd, -1);
meaning they let the system select the backlog.

Raising SOMAXCONN lowers chance of the port being unavailable under
even small SYNFLOOD attack, and reduces possibilities of side channel
vulnerabilities.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Yue Cao <ycao009@ucr.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
The kv*alloc()-family was missing kvcalloc(). Adding this allows for
2-argument multiplication conversions of kvzalloc(a * b, ...) into
kvcalloc(a, b, ...).

Signed-off-by: Kees Cook <keescook@chromium.org>
This gives the user building their own kernel (or a Linux
distribution) the option of deciding whether or not to trust the CPU's
hardware random number generator (e.g., RDRAND for x86 CPU's) as being
correctly implemented and not having a back door introduced (perhaps
courtesy of a Nation State's law enforcement or intelligence
agencies).

This will prevent getrandom(2) from blocking, if there is a
willingness to trust the CPU manufacturer.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Instead of forcing a distro or other system builder to choose
at build time whether the CPU is trusted for CRNG seeding via
CONFIG_RANDOM_TRUST_CPU, provide a boot-time parameter for end users to
control the choice. The CONFIG will set the default state instead.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This patch moves the udp[46]_portaddr_hash()
to net/ip[v6].h.  The function name is renamed to
ipv[46]_portaddr_hash().

It will be used by a later patch which adds a second listener
hashtable hashed by the address and port.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The x86_capability array in cpuinfo_x86 is of type u32 and thus is
naturally aligned to 4 bytes. But, set_bit() and clear_bit() require the
array to be aligned to size of unsigned long (i.e. 8 bytes on 64-bit
systems).

The array pointer is handed into atomic bit operations. If the access is
not aligned to unsigned long then the atomic bit operations can end up
crossing a cache line boundary, which causes the CPU to do a full bus lock
as it can't lock both cache lines at once. The bus lock operation is heavy
weight and can cause severe performance degradation.

The upcoming #AC split lock detection mechanism will issue warnings for
this kind of access.

Force the alignment of the array to unsigned long. This avoids the massive
code changes which would be required when converting the array data type to
unsigned long.

[ tglx: Rewrote changelog so it contains information WHY this is required ]

Suggested-by: David Laight <David.Laight@aculab.com>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190916223958.27048-4-tony.luck@intel.com
@theLOICofFRANCE
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Take what you want, I'll delete my old project.

@gregkh
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gregkh commented Apr 26, 2020

Please send these to stable@vger.kernel.org as per the stable kernel rules documentation and I will be glad to take them.

Kernel development does not happen in github repos, sorry!

@gregkh gregkh closed this Apr 26, 2020
gregkh pushed a commit that referenced this pull request Apr 30, 2020
[ Upstream commit 8c702a5 ]

High frequency of PCI ioread calls during recovery flow may cause the
following trace on powerpc:

[ 248.670288] EEH: 2100000 reads ignored for recovering device at
location=Slot1 driver=mlx5_core pci addr=0000:01:00.1
[ 248.670331] EEH: Might be infinite loop in mlx5_core driver
[ 248.670361] CPU: 2 PID: 35247 Comm: kworker/u192:11 Kdump: loaded
Tainted: G OE ------------ 4.14.0-115.14.1.el7a.ppc64le #1
[ 248.670425] Workqueue: mlx5_health0000:01:00.1 health_recover_work
[mlx5_core]
[ 248.670471] Call Trace:
[ 248.670492] [c00020391c11b960] [c000000000c217ac] dump_stack+0xb0/0xf4
(unreliable)
[ 248.670548] [c00020391c11b9a0] [c000000000045818]
eeh_check_failure+0x5c8/0x630
[ 248.670631] [c00020391c11ba50] [c00000000068fce4]
ioread32be+0x114/0x1c0
[ 248.670692] [c00020391c11bac0] [c00800000dd8b400]
mlx5_error_sw_reset+0x160/0x510 [mlx5_core]
[ 248.670752] [c00020391c11bb60] [c00800000dd75824]
mlx5_disable_device+0x34/0x1d0 [mlx5_core]
[ 248.670822] [c00020391c11bbe0] [c00800000dd8affc]
health_recover_work+0x11c/0x3c0 [mlx5_core]
[ 248.670891] [c00020391c11bc80] [c000000000164fcc]
process_one_work+0x1bc/0x5f0
[ 248.670955] [c00020391c11bd20] [c000000000167f8c]
worker_thread+0xac/0x6b0
[ 248.671015] [c00020391c11bdc0] [c000000000171618] kthread+0x168/0x1b0
[ 248.671067] [c00020391c11be30] [c00000000000b65c]
ret_from_kernel_thread+0x5c/0x80

Reduce the PCI ioread frequency during recovery by using msleep()
instead of cond_resched()

Fixes: 3e5b72a ("net/mlx5: Issue SW reset on FW assert")
Signed-off-by: Moshe Shemesh <moshe@mellanox.com>
Reviewed-by: Feras Daoud <ferasda@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregkh pushed a commit that referenced this pull request Apr 30, 2020
commit b0151da upstream.

The default resource group ("rdtgroup_default") is associated with the
root of the resctrl filesystem and should never be removed. New resource
groups can be created as subdirectories of the resctrl filesystem and
they can be removed from user space.

There exists a safeguard in the directory removal code
(rdtgroup_rmdir()) that ensures that only subdirectories can be removed
by testing that the directory to be removed has to be a child of the
root directory.

A possible deadlock was recently fixed with

  334b0f4 ("x86/resctrl: Fix a deadlock due to inaccurate reference").

This fix involved associating the private data of the "mon_groups"
and "mon_data" directories to the resource group to which they belong
instead of NULL as before. A consequence of this change was that
the original safeguard code preventing removal of "mon_groups" and
"mon_data" found in the root directory failed resulting in attempts to
remove the default resource group that ends in a BUG:

  kernel BUG at mm/slub.c:3969!
  invalid opcode: 0000 [#1] SMP PTI

  Call Trace:
  rdtgroup_rmdir+0x16b/0x2c0
  kernfs_iop_rmdir+0x5c/0x90
  vfs_rmdir+0x7a/0x160
  do_rmdir+0x17d/0x1e0
  do_syscall_64+0x55/0x1d0
  entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fix this by improving the directory removal safeguard to ensure that
subdirectories of the resctrl root directory can only be removed if they
are a child of the resctrl filesystem's root _and_ not associated with
the default resource group.

Fixes: 334b0f4 ("x86/resctrl: Fix a deadlock due to inaccurate reference")
Reported-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/884cbe1773496b5dbec1b6bd11bb50cffa83603d.1584461853.git.reinette.chatre@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregkh pushed a commit that referenced this pull request Apr 30, 2020
[ Upstream commit 29566c9 ]

The space_info list is normally RCU protected and should be traversed
with rcu_read_lock held. There's a warning

  [29.104756] WARNING: suspicious RCU usage
  [29.105046] 5.6.0-rc4-next-20200305 #1 Not tainted
  [29.105231] -----------------------------
  [29.105401] fs/btrfs/block-group.c:2011 RCU-list traversed in non-reader section!!

pointing out that the locking is missing in btrfs_read_block_groups.
However this is not necessary as the list traversal happens at mount
time when there's no other thread potentially accessing the list.

To fix the warning and for consistency let's add the RCU lock/unlock,
the code won't be affected much as it's doing some lightweight
operations.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gregkh pushed a commit that referenced this pull request Apr 30, 2020
[ Upstream commit 696ac2e ]

Similar to commit 0266d81 ("acpi/processor: Prevent cpu hotplug
deadlock") except this is for acpi_processor_ffh_cstate_probe():

"The problem is that the work is scheduled on the current CPU from the
hotplug thread associated with that CPU.

It's not required to invoke these functions via the workqueue because
the hotplug thread runs on the target CPU already.

Check whether current is a per cpu thread pinned on the target CPU and
invoke the function directly to avoid the workqueue."

 WARNING: possible circular locking dependency detected
 ------------------------------------------------------
 cpuhp/1/15 is trying to acquire lock:
 ffffc90003447a28 ((work_completion)(&wfc.work)){+.+.}-{0:0}, at: __flush_work+0x4c6/0x630

 but task is already holding lock:
 ffffffffafa1c0e8 (cpuidle_lock){+.+.}-{3:3}, at: cpuidle_pause_and_lock+0x17/0x20

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> #1 (cpu_hotplug_lock){++++}-{0:0}:
 cpus_read_lock+0x3e/0xc0
 irq_calc_affinity_vectors+0x5f/0x91
 __pci_enable_msix_range+0x10f/0x9a0
 pci_alloc_irq_vectors_affinity+0x13e/0x1f0
 pci_alloc_irq_vectors_affinity at drivers/pci/msi.c:1208
 pqi_ctrl_init+0x72f/0x1618 [smartpqi]
 pqi_pci_probe.cold.63+0x882/0x892 [smartpqi]
 local_pci_probe+0x7a/0xc0
 work_for_cpu_fn+0x2e/0x50
 process_one_work+0x57e/0xb90
 worker_thread+0x363/0x5b0
 kthread+0x1f4/0x220
 ret_from_fork+0x27/0x50

 -> #0 ((work_completion)(&wfc.work)){+.+.}-{0:0}:
 __lock_acquire+0x2244/0x32a0
 lock_acquire+0x1a2/0x680
 __flush_work+0x4e6/0x630
 work_on_cpu+0x114/0x160
 acpi_processor_ffh_cstate_probe+0x129/0x250
 acpi_processor_evaluate_cst+0x4c8/0x580
 acpi_processor_get_power_info+0x86/0x740
 acpi_processor_hotplug+0xc3/0x140
 acpi_soft_cpu_online+0x102/0x1d0
 cpuhp_invoke_callback+0x197/0x1120
 cpuhp_thread_fun+0x252/0x2f0
 smpboot_thread_fn+0x255/0x440
 kthread+0x1f4/0x220
 ret_from_fork+0x27/0x50

 other info that might help us debug this:

 Chain exists of:
 (work_completion)(&wfc.work) --> cpuhp_state-up --> cpuidle_lock

 Possible unsafe locking scenario:

 CPU0                    CPU1
 ----                    ----
 lock(cpuidle_lock);
                         lock(cpuhp_state-up);
                         lock(cpuidle_lock);
 lock((work_completion)(&wfc.work));

 *** DEADLOCK ***

 3 locks held by cpuhp/1/15:
 #0: ffffffffaf51ab10 (cpu_hotplug_lock){++++}-{0:0}, at: cpuhp_thread_fun+0x69/0x2f0
 #1: ffffffffaf51ad40 (cpuhp_state-up){+.+.}-{0:0}, at: cpuhp_thread_fun+0x69/0x2f0
 #2: ffffffffafa1c0e8 (cpuidle_lock){+.+.}-{3:3}, at: cpuidle_pause_and_lock+0x17/0x20

 Call Trace:
 dump_stack+0xa0/0xea
 print_circular_bug.cold.52+0x147/0x14c
 check_noncircular+0x295/0x2d0
 __lock_acquire+0x2244/0x32a0
 lock_acquire+0x1a2/0x680
 __flush_work+0x4e6/0x630
 work_on_cpu+0x114/0x160
 acpi_processor_ffh_cstate_probe+0x129/0x250
 acpi_processor_evaluate_cst+0x4c8/0x580
 acpi_processor_get_power_info+0x86/0x740
 acpi_processor_hotplug+0xc3/0x140
 acpi_soft_cpu_online+0x102/0x1d0
 cpuhp_invoke_callback+0x197/0x1120
 cpuhp_thread_fun+0x252/0x2f0
 smpboot_thread_fn+0x255/0x440
 kthread+0x1f4/0x220
 ret_from_fork+0x27/0x50

Signed-off-by: Qian Cai <cai@lca.pw>
Tested-by: Borislav Petkov <bp@suse.de>
[ rjw: Subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gregkh pushed a commit that referenced this pull request Apr 30, 2020
commit d3ec10a upstream.

A lockdep circular locking dependency report was seen when running a
keyutils test:

[12537.027242] ======================================================
[12537.059309] WARNING: possible circular locking dependency detected
[12537.088148] 4.18.0-147.7.1.el8_1.x86_64+debug #1 Tainted: G OE    --------- -  -
[12537.125253] ------------------------------------------------------
[12537.153189] keyctl/25598 is trying to acquire lock:
[12537.175087] 000000007c39f96c (&mm->mmap_sem){++++}, at: __might_fault+0xc4/0x1b0
[12537.208365]
[12537.208365] but task is already holding lock:
[12537.234507] 000000003de5b58d (&type->lock_class){++++}, at: keyctl_read_key+0x15a/0x220
[12537.270476]
[12537.270476] which lock already depends on the new lock.
[12537.270476]
[12537.307209]
[12537.307209] the existing dependency chain (in reverse order) is:
[12537.340754]
[12537.340754] -> #3 (&type->lock_class){++++}:
[12537.367434]        down_write+0x4d/0x110
[12537.385202]        __key_link_begin+0x87/0x280
[12537.405232]        request_key_and_link+0x483/0xf70
[12537.427221]        request_key+0x3c/0x80
[12537.444839]        dns_query+0x1db/0x5a5 [dns_resolver]
[12537.468445]        dns_resolve_server_name_to_ip+0x1e1/0x4d0 [cifs]
[12537.496731]        cifs_reconnect+0xe04/0x2500 [cifs]
[12537.519418]        cifs_readv_from_socket+0x461/0x690 [cifs]
[12537.546263]        cifs_read_from_socket+0xa0/0xe0 [cifs]
[12537.573551]        cifs_demultiplex_thread+0x311/0x2db0 [cifs]
[12537.601045]        kthread+0x30c/0x3d0
[12537.617906]        ret_from_fork+0x3a/0x50
[12537.636225]
[12537.636225] -> #2 (root_key_user.cons_lock){+.+.}:
[12537.664525]        __mutex_lock+0x105/0x11f0
[12537.683734]        request_key_and_link+0x35a/0xf70
[12537.705640]        request_key+0x3c/0x80
[12537.723304]        dns_query+0x1db/0x5a5 [dns_resolver]
[12537.746773]        dns_resolve_server_name_to_ip+0x1e1/0x4d0 [cifs]
[12537.775607]        cifs_reconnect+0xe04/0x2500 [cifs]
[12537.798322]        cifs_readv_from_socket+0x461/0x690 [cifs]
[12537.823369]        cifs_read_from_socket+0xa0/0xe0 [cifs]
[12537.847262]        cifs_demultiplex_thread+0x311/0x2db0 [cifs]
[12537.873477]        kthread+0x30c/0x3d0
[12537.890281]        ret_from_fork+0x3a/0x50
[12537.908649]
[12537.908649] -> #1 (&tcp_ses->srv_mutex){+.+.}:
[12537.935225]        __mutex_lock+0x105/0x11f0
[12537.954450]        cifs_call_async+0x102/0x7f0 [cifs]
[12537.977250]        smb2_async_readv+0x6c3/0xc90 [cifs]
[12538.000659]        cifs_readpages+0x120a/0x1e50 [cifs]
[12538.023920]        read_pages+0xf5/0x560
[12538.041583]        __do_page_cache_readahead+0x41d/0x4b0
[12538.067047]        ondemand_readahead+0x44c/0xc10
[12538.092069]        filemap_fault+0xec1/0x1830
[12538.111637]        __do_fault+0x82/0x260
[12538.129216]        do_fault+0x419/0xfb0
[12538.146390]        __handle_mm_fault+0x862/0xdf0
[12538.167408]        handle_mm_fault+0x154/0x550
[12538.187401]        __do_page_fault+0x42f/0xa60
[12538.207395]        do_page_fault+0x38/0x5e0
[12538.225777]        page_fault+0x1e/0x30
[12538.243010]
[12538.243010] -> #0 (&mm->mmap_sem){++++}:
[12538.267875]        lock_acquire+0x14c/0x420
[12538.286848]        __might_fault+0x119/0x1b0
[12538.306006]        keyring_read_iterator+0x7e/0x170
[12538.327936]        assoc_array_subtree_iterate+0x97/0x280
[12538.352154]        keyring_read+0xe9/0x110
[12538.370558]        keyctl_read_key+0x1b9/0x220
[12538.391470]        do_syscall_64+0xa5/0x4b0
[12538.410511]        entry_SYSCALL_64_after_hwframe+0x6a/0xdf
[12538.435535]
[12538.435535] other info that might help us debug this:
[12538.435535]
[12538.472829] Chain exists of:
[12538.472829]   &mm->mmap_sem --> root_key_user.cons_lock --> &type->lock_class
[12538.472829]
[12538.524820]  Possible unsafe locking scenario:
[12538.524820]
[12538.551431]        CPU0                    CPU1
[12538.572654]        ----                    ----
[12538.595865]   lock(&type->lock_class);
[12538.613737]                                lock(root_key_user.cons_lock);
[12538.644234]                                lock(&type->lock_class);
[12538.672410]   lock(&mm->mmap_sem);
[12538.687758]
[12538.687758]  *** DEADLOCK ***
[12538.687758]
[12538.714455] 1 lock held by keyctl/25598:
[12538.732097]  #0: 000000003de5b58d (&type->lock_class){++++}, at: keyctl_read_key+0x15a/0x220
[12538.770573]
[12538.770573] stack backtrace:
[12538.790136] CPU: 2 PID: 25598 Comm: keyctl Kdump: loaded Tainted: G
[12538.844855] Hardware name: HP ProLiant DL360 Gen9/ProLiant DL360 Gen9, BIOS P89 12/27/2015
[12538.881963] Call Trace:
[12538.892897]  dump_stack+0x9a/0xf0
[12538.907908]  print_circular_bug.isra.25.cold.50+0x1bc/0x279
[12538.932891]  ? save_trace+0xd6/0x250
[12538.948979]  check_prev_add.constprop.32+0xc36/0x14f0
[12538.971643]  ? keyring_compare_object+0x104/0x190
[12538.992738]  ? check_usage+0x550/0x550
[12539.009845]  ? sched_clock+0x5/0x10
[12539.025484]  ? sched_clock_cpu+0x18/0x1e0
[12539.043555]  __lock_acquire+0x1f12/0x38d0
[12539.061551]  ? trace_hardirqs_on+0x10/0x10
[12539.080554]  lock_acquire+0x14c/0x420
[12539.100330]  ? __might_fault+0xc4/0x1b0
[12539.119079]  __might_fault+0x119/0x1b0
[12539.135869]  ? __might_fault+0xc4/0x1b0
[12539.153234]  keyring_read_iterator+0x7e/0x170
[12539.172787]  ? keyring_read+0x110/0x110
[12539.190059]  assoc_array_subtree_iterate+0x97/0x280
[12539.211526]  keyring_read+0xe9/0x110
[12539.227561]  ? keyring_gc_check_iterator+0xc0/0xc0
[12539.249076]  keyctl_read_key+0x1b9/0x220
[12539.266660]  do_syscall_64+0xa5/0x4b0
[12539.283091]  entry_SYSCALL_64_after_hwframe+0x6a/0xdf

One way to prevent this deadlock scenario from happening is to not
allow writing to userspace while holding the key semaphore. Instead,
an internal buffer is allocated for getting the keys out from the
read method first before copying them out to userspace without holding
the lock.

That requires taking out the __user modifier from all the relevant
read methods as well as additional changes to not use any userspace
write helpers. That is,

  1) The put_user() call is replaced by a direct copy.
  2) The copy_to_user() call is replaced by memcpy().
  3) All the fault handling code is removed.

Compiling on a x86-64 system, the size of the rxrpc_read() function is
reduced from 3795 bytes to 2384 bytes with this patch.

Fixes: ^1da177e4c3f4 ("Linux-2.6.12-rc2")
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregkh pushed a commit that referenced this pull request Apr 30, 2020
[ Upstream commit a95a0a1 ]

MCE handling on pSeries platform fails as recent rework to use common
code for pSeries and PowerNV in machine check error handling tries to
access per-cpu variables in realmode. The per-cpu variables may be
outside the RMO region on pSeries platform and needs translation to be
enabled for access. Just moving these per-cpu variable into RMO region
did'nt help because we queue some work to workqueues in real mode, which
again tries to touch per-cpu variables. Also fwnmi_release_errinfo()
cannot be called when translation is not enabled.

This patch fixes this by enabling translation in the exception handler
when all required real mode handling is done. This change only affects
the pSeries platform.

Without this fix below kernel crash is seen on injecting
SLB multihit:

BUG: Unable to handle kernel data access on read at 0xc00000027b205950
Faulting instruction address: 0xc00000000003b7e0
Oops: Kernel access of bad area, sig: 11 [#1]
LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
Modules linked in: mcetest_slb(OE+) af_packet(E) xt_tcpudp(E) ip6t_rpfilter(E) ip6t_REJECT(E) ipt_REJECT(E) xt_conntrack(E) ip_set(E) nfnetlink(E) ebtable_nat(E) ebtable_broute(E) ip6table_nat(E) ip6table_mangle(E) ip6table_raw(E) ip6table_security(E) iptable_nat(E) nf_nat(E) nf_conntrack(E) nf_defrag_ipv6(E) nf_defrag_ipv4(E) iptable_mangle(E) iptable_raw(E) iptable_security(E) ebtable_filter(E) ebtables(E) ip6table_filter(E) ip6_tables(E) iptable_filter(E) ip_tables(E) x_tables(E) xfs(E) ibmveth(E) vmx_crypto(E) gf128mul(E) uio_pdrv_genirq(E) uio(E) crct10dif_vpmsum(E) rtc_generic(E) btrfs(E) libcrc32c(E) xor(E) zstd_decompress(E) zstd_compress(E) raid6_pq(E) sr_mod(E) sd_mod(E) cdrom(E) ibmvscsi(E) scsi_transport_srp(E) crc32c_vpmsum(E) dm_mod(E) sg(E) scsi_mod(E)
CPU: 34 PID: 8154 Comm: insmod Kdump: loaded Tainted: G OE 5.5.0-mahesh #1
NIP: c00000000003b7e0 LR: c0000000000f2218 CTR: 0000000000000000
REGS: c000000007dcb960 TRAP: 0300 Tainted: G OE (5.5.0-mahesh)
MSR: 8000000000001003 <SF,ME,RI,LE> CR: 28002428 XER: 20040000
CFAR: c0000000000f2214 DAR: c00000027b205950 DSISR: 40000000 IRQMASK: 0
GPR00: c0000000000f2218 c000000007dcbbf0 c000000001544800 c000000007dcbd70
GPR04: 0000000000000001 c000000007dcbc98 c008000000d00258 c0080000011c0000
GPR08: 0000000000000000 0000000300000003 c000000001035950 0000000003000048
GPR12: 000000027a1d0000 c000000007f9c000 0000000000000558 0000000000000000
GPR16: 0000000000000540 c008000001110000 c008000001110540 0000000000000000
GPR20: c00000000022af10 c00000025480fd70 c008000001280000 c00000004bfbb300
GPR24: c000000001442330 c00800000800000d c008000008000000 4009287a77000510
GPR28: 0000000000000000 0000000000000002 c000000001033d30 0000000000000001
NIP [c00000000003b7e0] save_mce_event+0x30/0x240
LR [c0000000000f2218] pseries_machine_check_realmode+0x2c8/0x4f0
Call Trace:
Instruction dump:
3c4c0151 38429050 7c0802a6 60000000 fbc1fff0 fbe1fff8 f821ffd1 3d42ffaf
3fc2ffaf e98d0030 394a1150 3bdef530 <7d6a62aa> 1d2b0048 2f8b0063 380b0001
---[ end trace 46fd63f36bbdd940 ]---

Fixes: 9ca766f ("powerpc/64s/pseries: machine check convert to use common event code")
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200320110119.10207-1-ganeshgr@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
gregkh pushed a commit that referenced this pull request Apr 30, 2020
[ Upstream commit 4dee15b ]

In the macvlan_device_event(), the list_first_entry_or_null() is used.
This function could return null pointer if there is no node.
But, the macvlan module doesn't check the null pointer.
So, null-ptr-deref would occur.

      bond0
        |
   +----+-----+
   |          |
macvlan0   macvlan1
   |          |
 dummy0     dummy1

The problem scenario.
If dummy1 is removed,
1. ->dellink() of dummy1 is called.
2. NETDEV_UNREGISTER of dummy1 notification is sent to macvlan module.
3. ->dellink() of macvlan1 is called.
4. NETDEV_UNREGISTER of macvlan1 notification is sent to bond module.
5. __bond_release_one() is called and it internally calls
   dev_set_mac_address().
6. dev_set_mac_address() calls the ->ndo_set_mac_address() of macvlan1,
   which is macvlan_set_mac_address().
7. macvlan_set_mac_address() calls the dev_set_mac_address() with dummy1.
8. NETDEV_CHANGEADDR of dummy1 is sent to macvlan module.
9. In the macvlan_device_event(), it calls list_first_entry_or_null().
At this point, dummy1 and macvlan1 were removed.
So, list_first_entry_or_null() will return NULL.

Test commands:
    ip netns add nst
    ip netns exec nst ip link add bond0 type bond
    for i in {0..10}
    do
        ip netns exec nst ip link add dummy$i type dummy
	ip netns exec nst ip link add macvlan$i link dummy$i \
		type macvlan mode passthru
	ip netns exec nst ip link set macvlan$i master bond0
    done
    ip netns del nst

Splat looks like:
[   40.585687][  T146] general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP DEI
[   40.587249][  T146] KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
[   40.588342][  T146] CPU: 1 PID: 146 Comm: kworker/u8:2 Not tainted 5.7.0-rc1+ #532
[   40.589299][  T146] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[   40.590469][  T146] Workqueue: netns cleanup_net
[   40.591045][  T146] RIP: 0010:macvlan_device_event+0x4e2/0x900 [macvlan]
[   40.591905][  T146] Code: 00 00 00 00 00 fc ff df 80 3c 06 00 0f 85 45 02 00 00 48 89 da 48 b8 00 00 00 00 00 fc ff d2
[   40.594126][  T146] RSP: 0018:ffff88806116f4a0 EFLAGS: 00010246
[   40.594783][  T146] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
[   40.595653][  T146] RDX: 0000000000000000 RSI: ffff88806547ddd8 RDI: ffff8880540f1360
[   40.596495][  T146] RBP: ffff88804011a808 R08: fffffbfff4fb8421 R09: fffffbfff4fb8421
[   40.597377][  T146] R10: ffffffffa7dc2107 R11: 0000000000000000 R12: 0000000000000008
[   40.598186][  T146] R13: ffff88804011a000 R14: ffff8880540f1000 R15: 1ffff1100c22de9a
[   40.599012][  T146] FS:  0000000000000000(0000) GS:ffff888067800000(0000) knlGS:0000000000000000
[   40.600004][  T146] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   40.600665][  T146] CR2: 00005572d3a807b8 CR3: 000000005fcf4003 CR4: 00000000000606e0
[   40.601485][  T146] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   40.602461][  T146] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   40.603443][  T146] Call Trace:
[   40.603871][  T146]  ? nf_tables_dump_setelem+0xa0/0xa0 [nf_tables]
[   40.604587][  T146]  ? macvlan_uninit+0x100/0x100 [macvlan]
[   40.605212][  T146]  ? __module_text_address+0x13/0x140
[   40.605842][  T146]  notifier_call_chain+0x90/0x160
[   40.606477][  T146]  dev_set_mac_address+0x28e/0x3f0
[   40.607117][  T146]  ? netdev_notify_peers+0xc0/0xc0
[   40.607762][  T146]  ? __module_text_address+0x13/0x140
[   40.608440][  T146]  ? notifier_call_chain+0x90/0x160
[   40.609097][  T146]  ? dev_set_mac_address+0x1f0/0x3f0
[   40.609758][  T146]  dev_set_mac_address+0x1f0/0x3f0
[   40.610402][  T146]  ? __local_bh_enable_ip+0xe9/0x1b0
[   40.611071][  T146]  ? bond_hw_addr_flush+0x77/0x100 [bonding]
[   40.611823][  T146]  ? netdev_notify_peers+0xc0/0xc0
[   40.612461][  T146]  ? bond_hw_addr_flush+0x77/0x100 [bonding]
[   40.613213][  T146]  ? bond_hw_addr_flush+0x77/0x100 [bonding]
[   40.613963][  T146]  ? __local_bh_enable_ip+0xe9/0x1b0
[   40.614631][  T146]  ? bond_time_in_interval.isra.31+0x90/0x90 [bonding]
[   40.615484][  T146]  ? __bond_release_one+0x9f0/0x12c0 [bonding]
[   40.616230][  T146]  __bond_release_one+0x9f0/0x12c0 [bonding]
[   40.616949][  T146]  ? bond_enslave+0x47c0/0x47c0 [bonding]
[   40.617642][  T146]  ? lock_downgrade+0x730/0x730
[   40.618218][  T146]  ? check_flags.part.42+0x450/0x450
[   40.618850][  T146]  ? __mutex_unlock_slowpath+0xd0/0x670
[   40.619519][  T146]  ? trace_hardirqs_on+0x30/0x180
[   40.620117][  T146]  ? wait_for_completion+0x250/0x250
[   40.620754][  T146]  bond_netdev_event+0x822/0x970 [bonding]
[   40.621460][  T146]  ? __module_text_address+0x13/0x140
[   40.622097][  T146]  notifier_call_chain+0x90/0x160
[   40.622806][  T146]  rollback_registered_many+0x660/0xcf0
[   40.623522][  T146]  ? netif_set_real_num_tx_queues+0x780/0x780
[   40.624290][  T146]  ? notifier_call_chain+0x90/0x160
[   40.624957][  T146]  ? netdev_upper_dev_unlink+0x114/0x180
[   40.625686][  T146]  ? __netdev_adjacent_dev_unlink_neighbour+0x30/0x30
[   40.626421][  T146]  ? mutex_is_locked+0x13/0x50
[   40.627016][  T146]  ? unregister_netdevice_queue+0xf2/0x240
[   40.627663][  T146]  unregister_netdevice_many.part.134+0x13/0x1b0
[   40.628362][  T146]  default_device_exit_batch+0x2d9/0x390
[   40.628987][  T146]  ? unregister_netdevice_many+0x40/0x40
[   40.629615][  T146]  ? dev_change_net_namespace+0xcb0/0xcb0
[   40.630279][  T146]  ? prepare_to_wait_exclusive+0x2e0/0x2e0
[   40.630943][  T146]  ? ops_exit_list.isra.9+0x97/0x140
[   40.631554][  T146]  cleanup_net+0x441/0x890
[ ... ]

Fixes: e289fd2 ("macvlan: fix the problem when mac address changes for passthru mode")
Reported-by: syzbot+5035b1f9dc7ea4558d5a@syzkaller.appspotmail.com
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregkh pushed a commit that referenced this pull request Apr 30, 2020
commit 56df70a upstream.

find_mergeable_vma() can return NULL.  In this case, it leads to a crash
when we access vm_mm(its offset is 0x40) later in write_protect_page.
And this case did happen on our server.  The following call trace is
captured in kernel 4.19 with the following patch applied and KSM zero
page enabled on our server.

  commit e86c59b ("mm/ksm: improve deduplication of zero pages with colouring")

So add a vma check to fix it.

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000040
  Oops: 0000 [#1] SMP NOPTI
  CPU: 9 PID: 510 Comm: ksmd Kdump: loaded Tainted: G OE 4.19.36.bsk.9-amd64 #4.19.36.bsk.9
  RIP: try_to_merge_one_page+0xc7/0x760
  Code: 24 58 65 48 33 34 25 28 00 00 00 89 e8 0f 85 a3 06 00 00 48 83 c4
        60 5b 5d 41 5c 41 5d 41 5e 41 5f c3 48 8b 46 08 a8 01 75 b8 <49>
        8b 44 24 40 4c 8d 7c 24 20 b9 07 00 00 00 4c 89 e6 4c 89 ff 48
  RSP: 0018:ffffadbdd9fffdb0 EFLAGS: 00010246
  RAX: ffffda83ffd4be08 RBX: ffffda83ffd4be40 RCX: 0000002c6e800000
  RDX: 0000000000000000 RSI: ffffda83ffd4be40 RDI: 0000000000000000
  RBP: ffffa11939f02ec0 R08: 0000000094e1a447 R09: 00000000abe76577
  R10: 0000000000000962 R11: 0000000000004e6a R12: 0000000000000000
  R13: ffffda83b1e06380 R14: ffffa18f31f072c0 R15: ffffda83ffd4be40
  FS: 0000000000000000(0000) GS:ffffa0da43b80000(0000) knlGS:0000000000000000
  CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000000040 CR3: 0000002c77c0a003 CR4: 00000000007626e0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  PKRU: 55555554
  Call Trace:
    ksm_scan_thread+0x115e/0x1960
    kthread+0xf5/0x130
    ret_from_fork+0x1f/0x30

[songmuchun@bytedance.com: if the vma is out of date, just exit]
  Link: http://lkml.kernel.org/r/20200416025034.29780-1-songmuchun@bytedance.com
[akpm@linux-foundation.org: add the conventional braces, replace /** with /*]
Fixes: e86c59b ("mm/ksm: improve deduplication of zero pages with colouring")
Co-developed-by: Xiongchun Duan <duanxiongchun@bytedance.com>
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Cc: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Cc: Markus Elfring <Markus.Elfring@web.de>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200416025034.29780-1-songmuchun@bytedance.com
Link: http://lkml.kernel.org/r/20200414132905.83819-1-songmuchun@bytedance.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregkh pushed a commit that referenced this pull request Apr 30, 2020
commit 9a9fc42 upstream.

If there is a lot(more then 16) of virtio-console devices
or virtio_console module is reloaded
- buffers 'vtermnos' and 'cons_ops' are overflowed.
In older kernels it overruns spinlock which leads to kernel freezing:
https://bugzilla.redhat.com/show_bug.cgi?id=1786239

To reproduce the issue, you can try simple script that
loads/unloads module. Something like this:
while [ 1 ]
do
  modprobe virtio_console
  sleep 2
  modprobe -r virtio_console
  sleep 2
done

Description of problem:
Guest get 'Call Trace' when loading module "virtio_console"
and unloading it frequently - clearly reproduced on kernel-4.18.0:

[   81.498208] ------------[ cut here ]------------
[   81.499263] pvqspinlock: lock 0xffffffff92080020 has corrupted value 0xc0774ca0!
[   81.501000] WARNING: CPU: 0 PID: 785 at kernel/locking/qspinlock_paravirt.h:500 __pv_queued_spin_unlock_slowpath+0xc0/0xd0
[   81.503173] Modules linked in: virtio_console fuse xt_CHECKSUM ipt_MASQUERADE xt_conntrack ipt_REJECT nft_counter nf_nat_tftp nft_objref nf_conntrack_tftp tun bridge stp llc nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nf_tables_set nft_chain_nat_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 nft_chain_route_ipv6 nft_chain_nat_ipv4 nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack nft_chain_route_ipv4 ip6_tables nft_compat ip_set nf_tables nfnetlink sunrpc bochs_drm drm_vram_helper ttm drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops drm i2c_piix4 pcspkr crct10dif_pclmul crc32_pclmul joydev ghash_clmulni_intel ip_tables xfs libcrc32c sd_mod sg ata_generic ata_piix virtio_net libata crc32c_intel net_failover failover serio_raw virtio_scsi dm_mirror dm_region_hash dm_log dm_mod [last unloaded: virtio_console]
[   81.517019] CPU: 0 PID: 785 Comm: kworker/0:2 Kdump: loaded Not tainted 4.18.0-167.el8.x86_64 #1
[   81.518639] Hardware name: Red Hat KVM, BIOS 1.12.0-5.scrmod+el8.2.0+5159+d8aa4d83 04/01/2014
[   81.520205] Workqueue: events control_work_handler [virtio_console]
[   81.521354] RIP: 0010:__pv_queued_spin_unlock_slowpath+0xc0/0xd0
[   81.522450] Code: 07 00 48 63 7a 10 e8 bf 64 f5 ff 66 90 c3 8b 05 e6 cf d6 01 85 c0 74 01 c3 8b 17 48 89 fe 48 c7 c7 38 4b 29 91 e8 3a 6c fa ff <0f> 0b c3 0f 0b 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 48
[   81.525830] RSP: 0018:ffffb51a01ffbd70 EFLAGS: 00010282
[   81.526798] RAX: 0000000000000000 RBX: 0000000000000010 RCX: 0000000000000000
[   81.528110] RDX: ffff9e66f1826480 RSI: ffff9e66f1816a08 RDI: ffff9e66f1816a08
[   81.529437] RBP: ffffffff9153ff10 R08: 000000000000026c R09: 0000000000000053
[   81.530732] R10: 0000000000000000 R11: ffffb51a01ffbc18 R12: ffff9e66cd682200
[   81.532133] R13: ffffffff9153ff10 R14: ffff9e6685569500 R15: ffff9e66cd682000
[   81.533442] FS:  0000000000000000(0000) GS:ffff9e66f1800000(0000) knlGS:0000000000000000
[   81.534914] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   81.535971] CR2: 00005624c55b14d0 CR3: 00000003a023c000 CR4: 00000000003406f0
[   81.537283] Call Trace:
[   81.537763]  __raw_callee_save___pv_queued_spin_unlock_slowpath+0x11/0x20
[   81.539011]  .slowpath+0x9/0xe
[   81.539585]  hvc_alloc+0x25e/0x300
[   81.540237]  init_port_console+0x28/0x100 [virtio_console]
[   81.541251]  handle_control_message.constprop.27+0x1c4/0x310 [virtio_console]
[   81.542546]  control_work_handler+0x70/0x10c [virtio_console]
[   81.543601]  process_one_work+0x1a7/0x3b0
[   81.544356]  worker_thread+0x30/0x390
[   81.545025]  ? create_worker+0x1a0/0x1a0
[   81.545749]  kthread+0x112/0x130
[   81.546358]  ? kthread_flush_work_fn+0x10/0x10
[   81.547183]  ret_from_fork+0x22/0x40
[   81.547842] ---[ end trace aa97649bd16c8655 ]---
[   83.546539] general protection fault: 0000 [#1] SMP NOPTI
[   83.547422] CPU: 5 PID: 3225 Comm: modprobe Kdump: loaded Tainted: G        W        --------- -  - 4.18.0-167.el8.x86_64 #1
[   83.549191] Hardware name: Red Hat KVM, BIOS 1.12.0-5.scrmod+el8.2.0+5159+d8aa4d83 04/01/2014
[   83.550544] RIP: 0010:__pv_queued_spin_lock_slowpath+0x19a/0x2a0
[   83.551504] Code: c4 c1 ea 12 41 be 01 00 00 00 4c 8d 6d 14 41 83 e4 03 8d 42 ff 49 c1 e4 05 48 98 49 81 c4 40 a5 02 00 4c 03 24 c5 60 48 34 91 <49> 89 2c 24 b8 00 80 00 00 eb 15 84 c0 75 0a 41 0f b6 54 24 14 84
[   83.554449] RSP: 0018:ffffb51a0323fdb0 EFLAGS: 00010202
[   83.555290] RAX: 000000000000301c RBX: ffffffff92080020 RCX: 0000000000000001
[   83.556426] RDX: 000000000000301d RSI: 0000000000000000 RDI: 0000000000000000
[   83.557556] RBP: ffff9e66f196a540 R08: 000000000000028a R09: ffff9e66d2757788
[   83.558688] R10: 0000000000000000 R11: 0000000000000000 R12: 646e61725f770b07
[   83.559821] R13: ffff9e66f196a554 R14: 0000000000000001 R15: 0000000000180000
[   83.560958] FS:  00007fd5032e8740(0000) GS:ffff9e66f1940000(0000) knlGS:0000000000000000
[   83.562233] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   83.563149] CR2: 00007fd5022b0da0 CR3: 000000038c334000 CR4: 00000000003406e0

Signed-off-by: Andrew Melnychenko <andrew@daynix.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200414191503.3471783-1-andrew@daynix.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregkh pushed a commit that referenced this pull request Apr 30, 2020
[ Upstream commit 8c702a5 ]

High frequency of PCI ioread calls during recovery flow may cause the
following trace on powerpc:

[ 248.670288] EEH: 2100000 reads ignored for recovering device at
location=Slot1 driver=mlx5_core pci addr=0000:01:00.1
[ 248.670331] EEH: Might be infinite loop in mlx5_core driver
[ 248.670361] CPU: 2 PID: 35247 Comm: kworker/u192:11 Kdump: loaded
Tainted: G OE ------------ 4.14.0-115.14.1.el7a.ppc64le #1
[ 248.670425] Workqueue: mlx5_health0000:01:00.1 health_recover_work
[mlx5_core]
[ 248.670471] Call Trace:
[ 248.670492] [c00020391c11b960] [c000000000c217ac] dump_stack+0xb0/0xf4
(unreliable)
[ 248.670548] [c00020391c11b9a0] [c000000000045818]
eeh_check_failure+0x5c8/0x630
[ 248.670631] [c00020391c11ba50] [c00000000068fce4]
ioread32be+0x114/0x1c0
[ 248.670692] [c00020391c11bac0] [c00800000dd8b400]
mlx5_error_sw_reset+0x160/0x510 [mlx5_core]
[ 248.670752] [c00020391c11bb60] [c00800000dd75824]
mlx5_disable_device+0x34/0x1d0 [mlx5_core]
[ 248.670822] [c00020391c11bbe0] [c00800000dd8affc]
health_recover_work+0x11c/0x3c0 [mlx5_core]
[ 248.670891] [c00020391c11bc80] [c000000000164fcc]
process_one_work+0x1bc/0x5f0
[ 248.670955] [c00020391c11bd20] [c000000000167f8c]
worker_thread+0xac/0x6b0
[ 248.671015] [c00020391c11bdc0] [c000000000171618] kthread+0x168/0x1b0
[ 248.671067] [c00020391c11be30] [c00000000000b65c]
ret_from_kernel_thread+0x5c/0x80

Reduce the PCI ioread frequency during recovery by using msleep()
instead of cond_resched()

Fixes: 3e5b72a ("net/mlx5: Issue SW reset on FW assert")
Signed-off-by: Moshe Shemesh <moshe@mellanox.com>
Reviewed-by: Feras Daoud <ferasda@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregkh pushed a commit that referenced this pull request Apr 30, 2020
commit b0151da upstream.

The default resource group ("rdtgroup_default") is associated with the
root of the resctrl filesystem and should never be removed. New resource
groups can be created as subdirectories of the resctrl filesystem and
they can be removed from user space.

There exists a safeguard in the directory removal code
(rdtgroup_rmdir()) that ensures that only subdirectories can be removed
by testing that the directory to be removed has to be a child of the
root directory.

A possible deadlock was recently fixed with

  334b0f4 ("x86/resctrl: Fix a deadlock due to inaccurate reference").

This fix involved associating the private data of the "mon_groups"
and "mon_data" directories to the resource group to which they belong
instead of NULL as before. A consequence of this change was that
the original safeguard code preventing removal of "mon_groups" and
"mon_data" found in the root directory failed resulting in attempts to
remove the default resource group that ends in a BUG:

  kernel BUG at mm/slub.c:3969!
  invalid opcode: 0000 [#1] SMP PTI

  Call Trace:
  rdtgroup_rmdir+0x16b/0x2c0
  kernfs_iop_rmdir+0x5c/0x90
  vfs_rmdir+0x7a/0x160
  do_rmdir+0x17d/0x1e0
  do_syscall_64+0x55/0x1d0
  entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fix this by improving the directory removal safeguard to ensure that
subdirectories of the resctrl root directory can only be removed if they
are a child of the resctrl filesystem's root _and_ not associated with
the default resource group.

Fixes: 334b0f4 ("x86/resctrl: Fix a deadlock due to inaccurate reference")
Reported-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/884cbe1773496b5dbec1b6bd11bb50cffa83603d.1584461853.git.reinette.chatre@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregkh pushed a commit that referenced this pull request Jan 30, 2026
[ Upstream commit e67c577 ]

Analog to commit db5b4e3 ("ip6_gre: make ip6gre_header() robust")

Over the years, syzbot found many ways to crash the kernel
in ipgre_header() [1].

This involves team or bonding drivers ability to dynamically
change their dev->needed_headroom and/or dev->hard_header_len

In this particular crash mld_newpack() allocated an skb
with a too small reserve/headroom, and by the time mld_sendpack()
was called, syzbot managed to attach an ipgre device.

[1]
skbuff: skb_under_panic: text:ffffffff89ea3cb7 len:2030915468 put:2030915372 head:ffff888058b43000 data:ffff887fdfa6e194 tail:0x120 end:0x6c0 dev:team0
 kernel BUG at net/core/skbuff.c:213 !
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 1 UID: 0 PID: 1322 Comm: kworker/1:9 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: mld mld_ifc_work
 RIP: 0010:skb_panic+0x157/0x160 net/core/skbuff.c:213
Call Trace:
 <TASK>
  skb_under_panic net/core/skbuff.c:223 [inline]
  skb_push+0xc3/0xe0 net/core/skbuff.c:2641
  ipgre_header+0x67/0x290 net/ipv4/ip_gre.c:897
  dev_hard_header include/linux/netdevice.h:3436 [inline]
  neigh_connected_output+0x286/0x460 net/core/neighbour.c:1618
  NF_HOOK_COND include/linux/netfilter.h:307 [inline]
  ip6_output+0x340/0x550 net/ipv6/ip6_output.c:247
  NF_HOOK+0x9e/0x380 include/linux/netfilter.h:318
  mld_sendpack+0x8d4/0xe60 net/ipv6/mcast.c:1855
  mld_send_cr net/ipv6/mcast.c:2154 [inline]
  mld_ifc_work+0x83e/0xd60 net/ipv6/mcast.c:2693
  process_one_work kernel/workqueue.c:3257 [inline]
  process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
  worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
  kthread+0x711/0x8a0 kernel/kthread.c:463
  ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

Fixes: c544193 ("GRE: Refactor GRE tunneling code.")
Reported-by: syzbot+7c134e1c3aa3283790b9@syzkaller.appspotmail.com
Closes: https://www.spinics.net/lists/netdev/msg1147302.html
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260108190214.1667040-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gregkh pushed a commit that referenced this pull request Jan 30, 2026
commit e707c59 upstream.

The Secondary Sample Point Source field has been
set to an incorrect value by some mistake in the
past

  0b01 - SSP_SRC_NO_SSP - SSP is not used.

for data bitrates above 1 MBit/s. The correct/default
value already used for lower bitrates is

  0b00 - SSP_SRC_MEAS_N_OFFSET - SSP position = TRV_DELAY
         (Measured Transmitter delay) + SSP_OFFSET.

The related configuration register structure is described
in section 3.1.46 SSP_CFG of the CTU CAN FD
IP CORE Datasheet.

The analysis leading to the proper configuration
is described in section 2.8.3 Secondary sampling point
of the datasheet.

The change has been tested on AMD/Xilinx Zynq
with the next CTU CN FD IP core versions:

 - 2.6 aka master in the "integration with Zynq-7000 system" test
   6.12.43-rt12+ #1 SMP PREEMPT_RT kernel with CTU CAN FD git
   driver (change already included in the driver repo)
 - older 2.5 snapshot with mainline kernels with this patch
   applied locally in the multiple CAN latency tester nightly runs
   6.18.0-rc4-rt3-dut #1 SMP PREEMPT_RT
   6.19.0-rc3-dut

The logs, the datasheet and sources are available at

 https://canbus.pages.fel.cvut.cz/

Signed-off-by: Ondrej Ille <ondrej.ille@gmail.com>
Signed-off-by: Pavel Pisa <pisa@fel.cvut.cz>
Link: https://patch.msgid.link/20260105111620.16580-1-pisa@fel.cvut.cz
Fixes: 2dcb8e8 ("can: ctucanfd: add support for CTU CAN FD open-source IP core - bus independent part.")
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregkh pushed a commit that referenced this pull request Jan 30, 2026
commit 2515071 upstream.

The GET_INSTANCE_ID macro that caused a kernel panic when accessing sysfs
attributes:

1. Off-by-one error: The loop condition used '<=' instead of '<',
   causing access beyond array bounds. Since array indices are 0-based
   and go from 0 to instances_count-1, the loop should use '<'.

2. Missing NULL check: The code dereferenced attr_name_kobj->name
   without checking if attr_name_kobj was NULL, causing a null pointer
   dereference in min_length_show() and other attribute show functions.

The panic occurred when fwupd tried to read BIOS configuration attributes:

  Oops: general protection fault [#1] SMP KASAN NOPTI
  KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
  RIP: 0010:min_length_show+0xcf/0x1d0 [hp_bioscfg]

Add a NULL check for attr_name_kobj before dereferencing and corrects
the loop boundary to match the pattern used elsewhere in the driver.

Cc: stable@vger.kernel.org
Fixes: 5f94f18 ("platform/x86: hp-bioscfg: bioscfg-h")
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://patch.msgid.link/20260115203725.828434-3-mario.limonciello@amd.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregkh pushed a commit that referenced this pull request Jan 30, 2026
…gs list

[ Upstream commit b97d5ee ]

The netdevsim driver lacks a protection mechanism for operations on the
bpf_bound_progs list. When the nsim_bpf_create_prog() performs
list_add_tail, it is possible that nsim_bpf_destroy_prog() is
simultaneously performs list_del. Concurrent operations on the list may
lead to list corruption and trigger a kernel crash as follows:

[  417.290971] kernel BUG at lib/list_debug.c:62!
[  417.290983] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
[  417.290992] CPU: 10 PID: 168 Comm: kworker/10:1 Kdump: loaded Not tainted 6.19.0-rc5 #1
[  417.291003] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[  417.291007] Workqueue: events bpf_prog_free_deferred
[  417.291021] RIP: 0010:__list_del_entry_valid_or_report+0xa7/0xc0
[  417.291034] Code: a8 ff 0f 0b 48 89 fe 48 89 ca 48 c7 c7 48 a1 eb ae e8 ed fb a8 ff 0f 0b 48 89 fe 48 89 c2 48 c7 c7 80 a1 eb ae e8 d9 fb a8 ff <0f> 0b 48 89 d1 48 c7 c7 d0 a1 eb ae 48 89 f2 48 89 c6 e8 c2 fb a8
[  417.291040] RSP: 0018:ffffb16a40807df8 EFLAGS: 00010246
[  417.291046] RAX: 000000000000006d RBX: ffff8e589866f500 RCX: 0000000000000000
[  417.291051] RDX: 0000000000000000 RSI: ffff8e59f7b23180 RDI: ffff8e59f7b23180
[  417.291055] RBP: ffffb16a412c9000 R08: 0000000000000000 R09: 0000000000000003
[  417.291059] R10: ffffb16a40807c80 R11: ffffffffaf9edce8 R12: ffff8e594427ac20
[  417.291063] R13: ffff8e59f7b44780 R14: ffff8e58800b7a05 R15: 0000000000000000
[  417.291074] FS:  0000000000000000(0000) GS:ffff8e59f7b00000(0000) knlGS:0000000000000000
[  417.291079] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  417.291083] CR2: 00007fc4083efe08 CR3: 00000001c3626006 CR4: 0000000000770ee0
[  417.291088] PKRU: 55555554
[  417.291091] Call Trace:
[  417.291096]  <TASK>
[  417.291103]  nsim_bpf_destroy_prog+0x31/0x80 [netdevsim]
[  417.291154]  __bpf_prog_offload_destroy+0x2a/0x80
[  417.291163]  bpf_prog_dev_bound_destroy+0x6f/0xb0
[  417.291171]  bpf_prog_free_deferred+0x18e/0x1a0
[  417.291178]  process_one_work+0x18a/0x3a0
[  417.291188]  worker_thread+0x27b/0x3a0
[  417.291197]  ? __pfx_worker_thread+0x10/0x10
[  417.291207]  kthread+0xe5/0x120
[  417.291214]  ? __pfx_kthread+0x10/0x10
[  417.291221]  ret_from_fork+0x31/0x50
[  417.291230]  ? __pfx_kthread+0x10/0x10
[  417.291236]  ret_from_fork_asm+0x1a/0x30
[  417.291246]  </TASK>

Add a mutex lock, to prevent simultaneous addition and deletion operations
on the list.

Fixes: 31d3ad8 ("netdevsim: add bpf offload support")
Reported-by: Yinhao Hu <dddddd@hust.edu.cn>
Reported-by: Kaiyan Mei <M202472210@hust.edu.cn>
Signed-off-by: Yun Lu <luyun@kylinos.cn>
Link: https://patch.msgid.link/20260116095308.11441-1-luyun_611@163.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gregkh pushed a commit that referenced this pull request Jan 30, 2026
[ Upstream commit 27880b0 ]

tcf_ife_encode() must make sure ife_encode() does not return NULL.

syzbot reported:

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
 RIP: 0010:ife_tlv_meta_encode+0x41/0xa0 net/ife/ife.c:166
CPU: 3 UID: 0 PID: 8990 Comm: syz.0.696 Not tainted syzkaller #0 PREEMPT(full)
Call Trace:
 <TASK>
  ife_encode_meta_u32+0x153/0x180 net/sched/act_ife.c:101
  tcf_ife_encode net/sched/act_ife.c:841 [inline]
  tcf_ife_act+0x1022/0x1de0 net/sched/act_ife.c:877
  tc_act include/net/tc_wrapper.h:130 [inline]
  tcf_action_exec+0x1c0/0xa20 net/sched/act_api.c:1152
  tcf_exts_exec include/net/pkt_cls.h:349 [inline]
  mall_classify+0x1a0/0x2a0 net/sched/cls_matchall.c:42
  tc_classify include/net/tc_wrapper.h:197 [inline]
  __tcf_classify net/sched/cls_api.c:1764 [inline]
  tcf_classify+0x7f2/0x1380 net/sched/cls_api.c:1860
  multiq_classify net/sched/sch_multiq.c:39 [inline]
  multiq_enqueue+0xe0/0x510 net/sched/sch_multiq.c:66
  dev_qdisc_enqueue+0x45/0x250 net/core/dev.c:4147
  __dev_xmit_skb net/core/dev.c:4262 [inline]
  __dev_queue_xmit+0x2998/0x46c0 net/core/dev.c:4798

Fixes: 295a6e0 ("net/sched: act_ife: Change to use ife module")
Reported-by: syzbot+5cf914f193dffde3bd3c@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/6970d61d.050a0220.706b.0010.GAE@google.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Yotam Gigi <yotam.gi@gmail.com>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20260121133724.3400020-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gregkh pushed a commit that referenced this pull request Jan 30, 2026
commit ea8ccfd upstream.

The code to restore a ZA context doesn't attempt to allocate the task's
sve_state before setting TIF_SME. Consequently, restoring a ZA context
can place a task into an invalid state where TIF_SME is set but the
task's sve_state is NULL.

In legitimate but uncommon cases where the ZA signal context was NOT
created by the kernel in the context of the same task (e.g. if the task
is saved/restored with something like CRIU), we have no guarantee that
sve_state had been allocated previously. In these cases, userspace can
enter streaming mode without trapping while sve_state is NULL, causing a
later NULL pointer dereference when the kernel attempts to store the
register state:

| # ./sigreturn-za
| Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
| Mem abort info:
|   ESR = 0x0000000096000046
|   EC = 0x25: DABT (current EL), IL = 32 bits
|   SET = 0, FnV = 0
|   EA = 0, S1PTW = 0
|   FSC = 0x06: level 2 translation fault
| Data abort info:
|   ISV = 0, ISS = 0x00000046, ISS2 = 0x00000000
|   CM = 0, WnR = 1, TnD = 0, TagAccess = 0
|   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
| user pgtable: 4k pages, 52-bit VAs, pgdp=0000000101f47c00
| [0000000000000000] pgd=08000001021d8403, p4d=0800000102274403, pud=0800000102275403, pmd=0000000000000000
| Internal error: Oops: 0000000096000046 [#1]  SMP
| Modules linked in:
| CPU: 0 UID: 0 PID: 153 Comm: sigreturn-za Not tainted 6.19.0-rc1 #1 PREEMPT
| Hardware name: linux,dummy-virt (DT)
| pstate: 214000c9 (nzCv daIF +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
| pc : sve_save_state+0x4/0xf0
| lr : fpsimd_save_user_state+0xb0/0x1c0
| sp : ffff80008070bcc0
| x29: ffff80008070bcc0 x28: fff00000c1ca4c40 x27: 63cfa172fb5cf658
| x26: fff00000c1ca5228 x25: 0000000000000000 x24: 0000000000000000
| x23: 0000000000000000 x22: fff00000c1ca4c40 x21: fff00000c1ca4c40
| x20: 0000000000000020 x19: fff00000ff6900f0 x18: 0000000000000000
| x17: fff05e8e0311f000 x16: 0000000000000000 x15: 028fca8f3bdaf21c
| x14: 0000000000000212 x13: fff00000c0209f10 x12: 0000000000000020
| x11: 0000000000200b20 x10: 0000000000000000 x9 : fff00000ff69dcc0
| x8 : 00000000000003f2 x7 : 0000000000000001 x6 : fff00000c1ca5b48
| x5 : fff05e8e0311f000 x4 : 0000000008000000 x3 : 0000000000000000
| x2 : 0000000000000001 x1 : fff00000c1ca5970 x0 : 0000000000000440
| Call trace:
|  sve_save_state+0x4/0xf0 (P)
|  fpsimd_thread_switch+0x48/0x198
|  __switch_to+0x20/0x1c0
|  __schedule+0x36c/0xce0
|  schedule+0x34/0x11c
|  exit_to_user_mode_loop+0x124/0x188
|  el0_interrupt+0xc8/0xd8
|  __el0_irq_handler_common+0x18/0x24
|  el0t_64_irq_handler+0x10/0x1c
|  el0t_64_irq+0x198/0x19c
| Code: 54000040 d51b4408 d65f03c0 d503245f (e5bb5800)
| ---[ end trace 0000000000000000 ]---

Fix this by having restore_za_context() ensure that the task's sve_state
is allocated, matching what we do when taking an SME trap. Any live
SVE/SSVE state (which is restored earlier from a separate signal
context) must be preserved, and hence this is not zeroed.

Fixes: 3978221 ("arm64/sme: Implement ZA signal handling")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: <stable@vger.kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregkh pushed a commit that referenced this pull request Jan 30, 2026
commit e2f8216 upstream.

A DABT is reported[1] on an android based system when resume from hiberate.
This happens because swsusp_arch_suspend_exit() is marked with SYM_CODE_*()
and does not have a CFI hash, but swsusp_arch_resume() will attempt to
verify the CFI hash when calling a copy of swsusp_arch_suspend_exit().

Given that there's an existing requirement that the entrypoint to
swsusp_arch_suspend_exit() is the first byte of the .hibernate_exit.text
section, we cannot fix this by marking swsusp_arch_suspend_exit() with
SYM_FUNC_*(). The simplest fix for now is to disable the CFI check in
swsusp_arch_resume().

Mark swsusp_arch_resume() as __nocfi to disable the CFI check.

[1]
[   22.991934][    T1] Unable to handle kernel paging request at virtual address 0000000109170ffc
[   22.991934][    T1] Mem abort info:
[   22.991934][    T1]   ESR = 0x0000000096000007
[   22.991934][    T1]   EC = 0x25: DABT (current EL), IL = 32 bits
[   22.991934][    T1]   SET = 0, FnV = 0
[   22.991934][    T1]   EA = 0, S1PTW = 0
[   22.991934][    T1]   FSC = 0x07: level 3 translation fault
[   22.991934][    T1] Data abort info:
[   22.991934][    T1]   ISV = 0, ISS = 0x00000007, ISS2 = 0x00000000
[   22.991934][    T1]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[   22.991934][    T1]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[   22.991934][    T1] [0000000109170ffc] user address but active_mm is swapper
[   22.991934][    T1] Internal error: Oops: 0000000096000007 [#1] PREEMPT SMP
[   22.991934][    T1] Dumping ftrace buffer:
[   22.991934][    T1]    (ftrace buffer empty)
[   22.991934][    T1] Modules linked in:
[   22.991934][    T1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.6.98-android15-8-g0b1d2aee7fc3-dirty-4k #1 688c7060a825a3ac418fe53881730b355915a419
[   22.991934][    T1] Hardware name: Unisoc UMS9360-base Board (DT)
[   22.991934][    T1] pstate: 804000c5 (Nzcv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[   22.991934][    T1] pc : swsusp_arch_resume+0x2ac/0x344
[   22.991934][    T1] lr : swsusp_arch_resume+0x294/0x344
[   22.991934][    T1] sp : ffffffc08006b960
[   22.991934][    T1] x29: ffffffc08006b9c0 x28: 0000000000000000 x27: 0000000000000000
[   22.991934][    T1] x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000820
[   22.991934][    T1] x23: ffffffd0817e3000 x22: ffffffd0817e3000 x21: 0000000000000000
[   22.991934][    T1] x20: ffffff8089171000 x19: ffffffd08252c8c8 x18: ffffffc080061058
[   22.991934][    T1] x17: 00000000529c6ef0 x16: 00000000529c6ef0 x15: 0000000000000004
[   22.991934][    T1] x14: ffffff8178c88000 x13: 0000000000000006 x12: 0000000000000000
[   22.991934][    T1] x11: 0000000000000015 x10: 0000000000000001 x9 : ffffffd082533000
[   22.991934][    T1] x8 : 0000000109171000 x7 : 205b5d3433393139 x6 : 392e32322020205b
[   22.991934][    T1] x5 : 000000010916f000 x4 : 000000008164b000 x3 : ffffff808a4e0530
[   22.991934][    T1] x2 : ffffffd08058e784 x1 : 0000000082326000 x0 : 000000010a283000
[   22.991934][    T1] Call trace:
[   22.991934][    T1]  swsusp_arch_resume+0x2ac/0x344
[   22.991934][    T1]  hibernation_restore+0x158/0x18c
[   22.991934][    T1]  load_image_and_restore+0xb0/0xec
[   22.991934][    T1]  software_resume+0xf4/0x19c
[   22.991934][    T1]  software_resume_initcall+0x34/0x78
[   22.991934][    T1]  do_one_initcall+0xe8/0x370
[   22.991934][    T1]  do_initcall_level+0xc8/0x19c
[   22.991934][    T1]  do_initcalls+0x70/0xc0
[   22.991934][    T1]  do_basic_setup+0x1c/0x28
[   22.991934][    T1]  kernel_init_freeable+0xe0/0x148
[   22.991934][    T1]  kernel_init+0x20/0x1a8
[   22.991934][    T1]  ret_from_fork+0x10/0x20
[   22.991934][    T1] Code: a9400a61 f94013e0 f9438923 f9400a64 (b85fc110)

Co-developed-by: Jeson Gao <jeson.gao@unisoc.com>
Signed-off-by: Jeson Gao <jeson.gao@unisoc.com>
Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: <stable@vger.kernel.org>
[catalin.marinas@arm.com: commit log updated by Mark Rutland]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregkh pushed a commit that referenced this pull request Jan 30, 2026
commit 90f9f5d upstream.

When creating a synthetic event based on an existing synthetic event that
had a stacktrace field and the new synthetic event used that field a
kernel crash occurred:

 ~# cd /sys/kernel/tracing
 ~# echo 's:stack unsigned long stack[];' > dynamic_events
 ~# echo 'hist:keys=prev_pid:s0=common_stacktrace if prev_state & 3' >> events/sched/sched_switch/trigger
 ~# echo 'hist:keys=next_pid:s1=$s0:onmatch(sched.sched_switch).trace(stack,$s1)' >> events/sched/sched_switch/trigger

The above creates a synthetic event that takes a stacktrace when a task
schedules out in a non-running state and passes that stacktrace to the
sched_switch event when that task schedules back in. It triggers the
"stack" synthetic event that has a stacktrace as its field (called "stack").

 ~# echo 's:syscall_stack s64 id; unsigned long stack[];' >> dynamic_events
 ~# echo 'hist:keys=common_pid:s2=stack' >> events/synthetic/stack/trigger
 ~# echo 'hist:keys=common_pid:s3=$s2,i0=id:onmatch(synthetic.stack).trace(syscall_stack,$i0,$s3)' >> events/raw_syscalls/sys_exit/trigger

The above makes another synthetic event called "syscall_stack" that
attaches the first synthetic event (stack) to the sys_exit trace event and
records the stacktrace from the stack event with the id of the system call
that is exiting.

When enabling this event (or using it in a historgram):

 ~# echo 1 > events/synthetic/syscall_stack/enable

Produces a kernel crash!

 BUG: unable to handle page fault for address: 0000000000400010
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 PGD 0 P4D 0
 Oops: Oops: 0000 [#1] SMP PTI
 CPU: 6 UID: 0 PID: 1257 Comm: bash Not tainted 6.16.3+deb14-amd64 #1 PREEMPT(lazy)  Debian 6.16.3-1
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.17.0-debian-1.17.0-1 04/01/2014
 RIP: 0010:trace_event_raw_event_synth+0x90/0x380
 Code: c5 00 00 00 00 85 d2 0f 84 e1 00 00 00 31 db eb 34 0f 1f 00 66 66 2e 0f 1f 84 00 00 00 00 00 66 66 2e 0f 1f 84 00 00 00 00 00 <49> 8b 04 24 48 83 c3 01 8d 0c c5 08 00 00 00 01 cd 41 3b 5d 40 0f
 RSP: 0018:ffffd2670388f958 EFLAGS: 00010202
 RAX: ffff8ba1065cc100 RBX: 0000000000000000 RCX: 0000000000000000
 RDX: 0000000000000001 RSI: fffff266ffda7b90 RDI: ffffd2670388f9b0
 RBP: 0000000000000010 R08: ffff8ba104e76000 R09: ffffd2670388fa50
 R10: ffff8ba102dd42e0 R11: ffffffff9a908970 R12: 0000000000400010
 R13: ffff8ba10a246400 R14: ffff8ba10a710220 R15: fffff266ffda7b90
 FS:  00007fa3bc63f740(0000) GS:ffff8ba2e0f48000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000400010 CR3: 0000000107f9e003 CR4: 0000000000172ef0
 Call Trace:
  <TASK>
  ? __tracing_map_insert+0x208/0x3a0
  action_trace+0x67/0x70
  event_hist_trigger+0x633/0x6d0
  event_triggers_call+0x82/0x130
  trace_event_buffer_commit+0x19d/0x250
  trace_event_raw_event_sys_exit+0x62/0xb0
  syscall_exit_work+0x9d/0x140
  do_syscall_64+0x20a/0x2f0
  ? trace_event_raw_event_sched_switch+0x12b/0x170
  ? save_fpregs_to_fpstate+0x3e/0x90
  ? _raw_spin_unlock+0xe/0x30
  ? finish_task_switch.isra.0+0x97/0x2c0
  ? __rseq_handle_notify_resume+0xad/0x4c0
  ? __schedule+0x4b8/0xd00
  ? restore_fpregs_from_fpstate+0x3c/0x90
  ? switch_fpu_return+0x5b/0xe0
  ? do_syscall_64+0x1ef/0x2f0
  ? do_fault+0x2e9/0x540
  ? __handle_mm_fault+0x7d1/0xf70
  ? count_memcg_events+0x167/0x1d0
  ? handle_mm_fault+0x1d7/0x2e0
  ? do_user_addr_fault+0x2c3/0x7f0
  entry_SYSCALL_64_after_hwframe+0x76/0x7e

The reason is that the stacktrace field is not labeled as such, and is
treated as a normal field and not as a dynamic event that it is.

In trace_event_raw_event_synth() the event is field is still treated as a
dynamic array, but the retrieval of the data is considered a normal field,
and the reference is just the meta data:

// Meta data is retrieved instead of a dynamic array
  str_val = (char *)(long)var_ref_vals[val_idx];

// Then when it tries to process it:
  len = *((unsigned long *)str_val) + 1;

It triggers a kernel page fault.

To fix this, first when defining the fields of the first synthetic event,
set the filter type to FILTER_STACKTRACE. This is used later by the second
synthetic event to know that this field is a stacktrace. When creating
the field of the new synthetic event, have it use this FILTER_STACKTRACE
to know to create a stacktrace field to copy the stacktrace into.

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Link: https://patch.msgid.link/20260122194824.6905a38e@gandalf.local.home
Fixes: 00cf3d6 ("tracing: Allow synthetic events to pass around stacktraces")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregkh pushed a commit that referenced this pull request Jan 30, 2026
[ Upstream commit 9910159 ]

When one iio device is a consumer of another, it is possible that
the ->info_exist_lock of both ends up being taken when reading the
value of the consumer device.

Since they currently belong to the same lockdep class (being
initialized in a single location with mutex_init()), that results in a
lockdep warning

         CPU0
         ----
    lock(&iio_dev_opaque->info_exist_lock);
    lock(&iio_dev_opaque->info_exist_lock);

   *** DEADLOCK ***

   May be due to missing lock nesting notation

  4 locks held by sensors/414:
   #0: c31fd6dc (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0x44/0x4e4
   #1: c4f5a1c4 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x1c/0xac
   #2: c2827548 (kn->active#34){.+.+}-{0:0}, at: kernfs_seq_start+0x30/0xac
   #3: c1dd2b6 (&iio_dev_opaque->info_exist_lock){+.+.}-{3:3}, at: iio_read_channel_processed_scale+0x24/0xd8

  stack backtrace:
  CPU: 0 UID: 0 PID: 414 Comm: sensors Not tainted 6.17.11 #5 NONE
  Hardware name: Generic AM33XX (Flattened Device Tree)
  Call trace:
   unwind_backtrace from show_stack+0x10/0x14
   show_stack from dump_stack_lvl+0x44/0x60
   dump_stack_lvl from print_deadlock_bug+0x2b8/0x334
   print_deadlock_bug from __lock_acquire+0x13a4/0x2ab0
   __lock_acquire from lock_acquire+0xd0/0x2c0
   lock_acquire from __mutex_lock+0xa0/0xe8c
   __mutex_lock from mutex_lock_nested+0x1c/0x24
   mutex_lock_nested from iio_read_channel_raw+0x20/0x6c
   iio_read_channel_raw from rescale_read_raw+0x128/0x1c4
   rescale_read_raw from iio_channel_read+0xe4/0xf4
   iio_channel_read from iio_read_channel_processed_scale+0x6c/0xd8
   iio_read_channel_processed_scale from iio_hwmon_read_val+0x68/0xbc
   iio_hwmon_read_val from dev_attr_show+0x18/0x48
   dev_attr_show from sysfs_kf_seq_show+0x80/0x110
   sysfs_kf_seq_show from seq_read_iter+0xdc/0x4e4
   seq_read_iter from vfs_read+0x238/0x2e4
   vfs_read from ksys_read+0x6c/0xec
   ksys_read from ret_fast_syscall+0x0/0x1c

Just as the mlock_key already has its own lockdep class, add a
lock_class_key for the info_exist mutex.

Note that this has in theory been a problem since before IIO first
left staging, but it only occurs when a chain of consumers is in use
and that is not often done.

Fixes: ac917a8 ("staging:iio:core set the iio_dev.info pointer to null on unregister under lock.")
Signed-off-by: Rasmus Villemoes <ravi@prevas.dk>
Reviewed-by: Peter Rosin <peda@axentia.se>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregkh pushed a commit that referenced this pull request Jan 30, 2026
[ Upstream commit 038a102 ]

The kernel test robot has reported:

 BUG: spinlock trylock failure on UP on CPU#0, kcompactd0/28
  lock: 0xffff888807e35ef0, .magic: dead4ead, .owner: kcompactd0/28, .owner_cpu: 0
 CPU: 0 UID: 0 PID: 28 Comm: kcompactd0 Not tainted 6.18.0-rc5-00127-ga06157804399 #1 PREEMPT  8cc09ef94dcec767faa911515ce9e609c45db470
 Call Trace:
  <IRQ>
  __dump_stack (lib/dump_stack.c:95)
  dump_stack_lvl (lib/dump_stack.c:123)
  dump_stack (lib/dump_stack.c:130)
  spin_dump (kernel/locking/spinlock_debug.c:71)
  do_raw_spin_trylock (kernel/locking/spinlock_debug.c:?)
  _raw_spin_trylock (include/linux/spinlock_api_smp.h:89 kernel/locking/spinlock.c:138)
  __free_frozen_pages (mm/page_alloc.c:2973)
  ___free_pages (mm/page_alloc.c:5295)
  __free_pages (mm/page_alloc.c:5334)
  tlb_remove_table_rcu (include/linux/mm.h:? include/linux/mm.h:3122 include/asm-generic/tlb.h:220 mm/mmu_gather.c:227 mm/mmu_gather.c:290)
  ? __cfi_tlb_remove_table_rcu (mm/mmu_gather.c:289)
  ? rcu_core (kernel/rcu/tree.c:?)
  rcu_core (include/linux/rcupdate.h:341 kernel/rcu/tree.c:2607 kernel/rcu/tree.c:2861)
  rcu_core_si (kernel/rcu/tree.c:2879)
  handle_softirqs (arch/x86/include/asm/jump_label.h:36 include/trace/events/irq.h:142 kernel/softirq.c:623)
  __irq_exit_rcu (arch/x86/include/asm/jump_label.h:36 kernel/softirq.c:725)
  irq_exit_rcu (kernel/softirq.c:741)
  sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1052)
  </IRQ>
  <TASK>
 RIP: 0010:_raw_spin_unlock_irqrestore (arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:152 kernel/locking/spinlock.c:194)
  free_pcppages_bulk (mm/page_alloc.c:1494)
  drain_pages_zone (include/linux/spinlock.h:391 mm/page_alloc.c:2632)
  __drain_all_pages (mm/page_alloc.c:2731)
  drain_all_pages (mm/page_alloc.c:2747)
  kcompactd (mm/compaction.c:3115)
  kthread (kernel/kthread.c:465)
  ? __cfi_kcompactd (mm/compaction.c:3166)
  ? __cfi_kthread (kernel/kthread.c:412)
  ret_from_fork (arch/x86/kernel/process.c:164)
  ? __cfi_kthread (kernel/kthread.c:412)
  ret_from_fork_asm (arch/x86/entry/entry_64.S:255)
  </TASK>

Matthew has analyzed the report and identified that in drain_page_zone()
we are in a section protected by spin_lock(&pcp->lock) and then get an
interrupt that attempts spin_trylock() on the same lock.  The code is
designed to work this way without disabling IRQs and occasionally fail the
trylock with a fallback.  However, the SMP=n spinlock implementation
assumes spin_trylock() will always succeed, and thus it's normally a
no-op.  Here the enabled lock debugging catches the problem, but otherwise
it could cause a corruption of the pcp structure.

The problem has been introduced by commit 5749077 ("mm/page_alloc:
leave IRQs enabled for per-cpu page allocations").  The pcp locking scheme
recognizes the need for disabling IRQs to prevent nesting spin_trylock()
sections on SMP=n, but the need to prevent the nesting in spin_lock() has
not been recognized.  Fix it by introducing local wrappers that change the
spin_lock() to spin_lock_iqsave() with SMP=n and use them in all places
that do spin_lock(&pcp->lock).

[vbabka@suse.cz: add pcp_ prefix to the spin_lock_irqsave wrappers, per Steven]
Link: https://lkml.kernel.org/r/20260105-fix-pcp-up-v1-1-5579662d2071@suse.cz
Fixes: 5749077 ("mm/page_alloc: leave IRQs enabled for per-cpu page allocations")
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202512101320.e2f2dd6f-lkp@intel.com
Analyzed-by: Matthew Wilcox <willy@infradead.org>
Link: https://lore.kernel.org/all/aUW05pyc9nZkvY-1@casper.infradead.org/
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ drop changes to decay_pcp_high() and zone_pcp_update_cacheinfo() ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregkh pushed a commit that referenced this pull request Jan 30, 2026
commit 2515071 upstream.

The GET_INSTANCE_ID macro that caused a kernel panic when accessing sysfs
attributes:

1. Off-by-one error: The loop condition used '<=' instead of '<',
   causing access beyond array bounds. Since array indices are 0-based
   and go from 0 to instances_count-1, the loop should use '<'.

2. Missing NULL check: The code dereferenced attr_name_kobj->name
   without checking if attr_name_kobj was NULL, causing a null pointer
   dereference in min_length_show() and other attribute show functions.

The panic occurred when fwupd tried to read BIOS configuration attributes:

  Oops: general protection fault [#1] SMP KASAN NOPTI
  KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
  RIP: 0010:min_length_show+0xcf/0x1d0 [hp_bioscfg]

Add a NULL check for attr_name_kobj before dereferencing and corrects
the loop boundary to match the pattern used elsewhere in the driver.

Cc: stable@vger.kernel.org
Fixes: 5f94f18 ("platform/x86: hp-bioscfg: bioscfg-h")
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://patch.msgid.link/20260115203725.828434-3-mario.limonciello@amd.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregkh pushed a commit that referenced this pull request Jan 30, 2026
…gs list

[ Upstream commit b97d5ee ]

The netdevsim driver lacks a protection mechanism for operations on the
bpf_bound_progs list. When the nsim_bpf_create_prog() performs
list_add_tail, it is possible that nsim_bpf_destroy_prog() is
simultaneously performs list_del. Concurrent operations on the list may
lead to list corruption and trigger a kernel crash as follows:

[  417.290971] kernel BUG at lib/list_debug.c:62!
[  417.290983] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
[  417.290992] CPU: 10 PID: 168 Comm: kworker/10:1 Kdump: loaded Not tainted 6.19.0-rc5 #1
[  417.291003] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[  417.291007] Workqueue: events bpf_prog_free_deferred
[  417.291021] RIP: 0010:__list_del_entry_valid_or_report+0xa7/0xc0
[  417.291034] Code: a8 ff 0f 0b 48 89 fe 48 89 ca 48 c7 c7 48 a1 eb ae e8 ed fb a8 ff 0f 0b 48 89 fe 48 89 c2 48 c7 c7 80 a1 eb ae e8 d9 fb a8 ff <0f> 0b 48 89 d1 48 c7 c7 d0 a1 eb ae 48 89 f2 48 89 c6 e8 c2 fb a8
[  417.291040] RSP: 0018:ffffb16a40807df8 EFLAGS: 00010246
[  417.291046] RAX: 000000000000006d RBX: ffff8e589866f500 RCX: 0000000000000000
[  417.291051] RDX: 0000000000000000 RSI: ffff8e59f7b23180 RDI: ffff8e59f7b23180
[  417.291055] RBP: ffffb16a412c9000 R08: 0000000000000000 R09: 0000000000000003
[  417.291059] R10: ffffb16a40807c80 R11: ffffffffaf9edce8 R12: ffff8e594427ac20
[  417.291063] R13: ffff8e59f7b44780 R14: ffff8e58800b7a05 R15: 0000000000000000
[  417.291074] FS:  0000000000000000(0000) GS:ffff8e59f7b00000(0000) knlGS:0000000000000000
[  417.291079] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  417.291083] CR2: 00007fc4083efe08 CR3: 00000001c3626006 CR4: 0000000000770ee0
[  417.291088] PKRU: 55555554
[  417.291091] Call Trace:
[  417.291096]  <TASK>
[  417.291103]  nsim_bpf_destroy_prog+0x31/0x80 [netdevsim]
[  417.291154]  __bpf_prog_offload_destroy+0x2a/0x80
[  417.291163]  bpf_prog_dev_bound_destroy+0x6f/0xb0
[  417.291171]  bpf_prog_free_deferred+0x18e/0x1a0
[  417.291178]  process_one_work+0x18a/0x3a0
[  417.291188]  worker_thread+0x27b/0x3a0
[  417.291197]  ? __pfx_worker_thread+0x10/0x10
[  417.291207]  kthread+0xe5/0x120
[  417.291214]  ? __pfx_kthread+0x10/0x10
[  417.291221]  ret_from_fork+0x31/0x50
[  417.291230]  ? __pfx_kthread+0x10/0x10
[  417.291236]  ret_from_fork_asm+0x1a/0x30
[  417.291246]  </TASK>

Add a mutex lock, to prevent simultaneous addition and deletion operations
on the list.

Fixes: 31d3ad8 ("netdevsim: add bpf offload support")
Reported-by: Yinhao Hu <dddddd@hust.edu.cn>
Reported-by: Kaiyan Mei <M202472210@hust.edu.cn>
Signed-off-by: Yun Lu <luyun@kylinos.cn>
Link: https://patch.msgid.link/20260116095308.11441-1-luyun_611@163.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gregkh pushed a commit that referenced this pull request Jan 30, 2026
…itives

[ Upstream commit c06343b ]

The "valid" readout delay between the two reads of the watchdog is larger
than the valid delta between the resulting watchdog and clocksource
intervals, which results in false positive watchdog results.

Assume TSC is the clocksource and HPET is the watchdog and both have a
uncertainty margin of 250us (default). The watchdog readout does:

  1) wdnow = read(HPET);
  2) csnow = read(TSC);
  3) wdend = read(HPET);

The valid window for the delta between #1 and #3 is calculated by the
uncertainty margins of the watchdog and the clocksource:

   m = 2 * watchdog.uncertainty_margin + cs.uncertainty margin;

which results in 750us for the TSC/HPET case.

The actual interval comparison uses a smaller margin:

   m = watchdog.uncertainty_margin + cs.uncertainty margin;

which results in 500us for the TSC/HPET case.

That means the following scenario will trigger the watchdog:

 Watchdog cycle N:

 1)       wdnow[N] = read(HPET);
 2)       csnow[N] = read(TSC);
 3)       wdend[N] = read(HPET);

Assume the delay between #1 and #2 is 100us and the delay between #1 and

 Watchdog cycle N + 1:

 4)       wdnow[N + 1] = read(HPET);
 5)       csnow[N + 1] = read(TSC);
 6)       wdend[N + 1] = read(HPET);

If the delay between #4 and #6 is within the 750us margin then any delay
between #4 and #5 which is larger than 600us will fail the interval check
and mark the TSC unstable because the intervals are calculated against the
previous value:

    wd_int = wdnow[N + 1] - wdnow[N];
    cs_int = csnow[N + 1] - csnow[N];

Putting the above delays in place this results in:

    cs_int = (wdnow[N + 1] + 610us) - (wdnow[N] + 100us);
 -> cs_int = wd_int + 510us;

which is obviously larger than the allowed 500us margin and results in
marking TSC unstable.

Fix this by using the same margin as the interval comparison. If the delay
between two watchdog reads is larger than that, then the readout was either
disturbed by interconnect congestion, NMIs or SMIs.

Fixes: 4ac1dd3 ("clocksource: Set cs_watchdog_read() checks based on .uncertainty_margin")
Reported-by: Daniel J Blueman <daniel@quora.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/lkml/20250602223251.496591-1-daniel@quora.org/
Link: https://patch.msgid.link/87bjjxc9dq.ffs@tglx
Signed-off-by: Sasha Levin <sashal@kernel.org>
gregkh pushed a commit that referenced this pull request Jan 30, 2026
[ Upstream commit 27880b0 ]

tcf_ife_encode() must make sure ife_encode() does not return NULL.

syzbot reported:

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
 RIP: 0010:ife_tlv_meta_encode+0x41/0xa0 net/ife/ife.c:166
CPU: 3 UID: 0 PID: 8990 Comm: syz.0.696 Not tainted syzkaller #0 PREEMPT(full)
Call Trace:
 <TASK>
  ife_encode_meta_u32+0x153/0x180 net/sched/act_ife.c:101
  tcf_ife_encode net/sched/act_ife.c:841 [inline]
  tcf_ife_act+0x1022/0x1de0 net/sched/act_ife.c:877
  tc_act include/net/tc_wrapper.h:130 [inline]
  tcf_action_exec+0x1c0/0xa20 net/sched/act_api.c:1152
  tcf_exts_exec include/net/pkt_cls.h:349 [inline]
  mall_classify+0x1a0/0x2a0 net/sched/cls_matchall.c:42
  tc_classify include/net/tc_wrapper.h:197 [inline]
  __tcf_classify net/sched/cls_api.c:1764 [inline]
  tcf_classify+0x7f2/0x1380 net/sched/cls_api.c:1860
  multiq_classify net/sched/sch_multiq.c:39 [inline]
  multiq_enqueue+0xe0/0x510 net/sched/sch_multiq.c:66
  dev_qdisc_enqueue+0x45/0x250 net/core/dev.c:4147
  __dev_xmit_skb net/core/dev.c:4262 [inline]
  __dev_queue_xmit+0x2998/0x46c0 net/core/dev.c:4798

Fixes: 295a6e0 ("net/sched: act_ife: Change to use ife module")
Reported-by: syzbot+5cf914f193dffde3bd3c@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/6970d61d.050a0220.706b.0010.GAE@google.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Yotam Gigi <yotam.gi@gmail.com>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20260121133724.3400020-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gregkh pushed a commit that referenced this pull request Jan 30, 2026
commit ea8ccfd upstream.

The code to restore a ZA context doesn't attempt to allocate the task's
sve_state before setting TIF_SME. Consequently, restoring a ZA context
can place a task into an invalid state where TIF_SME is set but the
task's sve_state is NULL.

In legitimate but uncommon cases where the ZA signal context was NOT
created by the kernel in the context of the same task (e.g. if the task
is saved/restored with something like CRIU), we have no guarantee that
sve_state had been allocated previously. In these cases, userspace can
enter streaming mode without trapping while sve_state is NULL, causing a
later NULL pointer dereference when the kernel attempts to store the
register state:

| # ./sigreturn-za
| Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
| Mem abort info:
|   ESR = 0x0000000096000046
|   EC = 0x25: DABT (current EL), IL = 32 bits
|   SET = 0, FnV = 0
|   EA = 0, S1PTW = 0
|   FSC = 0x06: level 2 translation fault
| Data abort info:
|   ISV = 0, ISS = 0x00000046, ISS2 = 0x00000000
|   CM = 0, WnR = 1, TnD = 0, TagAccess = 0
|   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
| user pgtable: 4k pages, 52-bit VAs, pgdp=0000000101f47c00
| [0000000000000000] pgd=08000001021d8403, p4d=0800000102274403, pud=0800000102275403, pmd=0000000000000000
| Internal error: Oops: 0000000096000046 [#1]  SMP
| Modules linked in:
| CPU: 0 UID: 0 PID: 153 Comm: sigreturn-za Not tainted 6.19.0-rc1 #1 PREEMPT
| Hardware name: linux,dummy-virt (DT)
| pstate: 214000c9 (nzCv daIF +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
| pc : sve_save_state+0x4/0xf0
| lr : fpsimd_save_user_state+0xb0/0x1c0
| sp : ffff80008070bcc0
| x29: ffff80008070bcc0 x28: fff00000c1ca4c40 x27: 63cfa172fb5cf658
| x26: fff00000c1ca5228 x25: 0000000000000000 x24: 0000000000000000
| x23: 0000000000000000 x22: fff00000c1ca4c40 x21: fff00000c1ca4c40
| x20: 0000000000000020 x19: fff00000ff6900f0 x18: 0000000000000000
| x17: fff05e8e0311f000 x16: 0000000000000000 x15: 028fca8f3bdaf21c
| x14: 0000000000000212 x13: fff00000c0209f10 x12: 0000000000000020
| x11: 0000000000200b20 x10: 0000000000000000 x9 : fff00000ff69dcc0
| x8 : 00000000000003f2 x7 : 0000000000000001 x6 : fff00000c1ca5b48
| x5 : fff05e8e0311f000 x4 : 0000000008000000 x3 : 0000000000000000
| x2 : 0000000000000001 x1 : fff00000c1ca5970 x0 : 0000000000000440
| Call trace:
|  sve_save_state+0x4/0xf0 (P)
|  fpsimd_thread_switch+0x48/0x198
|  __switch_to+0x20/0x1c0
|  __schedule+0x36c/0xce0
|  schedule+0x34/0x11c
|  exit_to_user_mode_loop+0x124/0x188
|  el0_interrupt+0xc8/0xd8
|  __el0_irq_handler_common+0x18/0x24
|  el0t_64_irq_handler+0x10/0x1c
|  el0t_64_irq+0x198/0x19c
| Code: 54000040 d51b4408 d65f03c0 d503245f (e5bb5800)
| ---[ end trace 0000000000000000 ]---

Fix this by having restore_za_context() ensure that the task's sve_state
is allocated, matching what we do when taking an SME trap. Any live
SVE/SSVE state (which is restored earlier from a separate signal
context) must be preserved, and hence this is not zeroed.

Fixes: 3978221 ("arm64/sme: Implement ZA signal handling")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: <stable@vger.kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregkh pushed a commit that referenced this pull request Jan 30, 2026
commit e2f8216 upstream.

A DABT is reported[1] on an android based system when resume from hiberate.
This happens because swsusp_arch_suspend_exit() is marked with SYM_CODE_*()
and does not have a CFI hash, but swsusp_arch_resume() will attempt to
verify the CFI hash when calling a copy of swsusp_arch_suspend_exit().

Given that there's an existing requirement that the entrypoint to
swsusp_arch_suspend_exit() is the first byte of the .hibernate_exit.text
section, we cannot fix this by marking swsusp_arch_suspend_exit() with
SYM_FUNC_*(). The simplest fix for now is to disable the CFI check in
swsusp_arch_resume().

Mark swsusp_arch_resume() as __nocfi to disable the CFI check.

[1]
[   22.991934][    T1] Unable to handle kernel paging request at virtual address 0000000109170ffc
[   22.991934][    T1] Mem abort info:
[   22.991934][    T1]   ESR = 0x0000000096000007
[   22.991934][    T1]   EC = 0x25: DABT (current EL), IL = 32 bits
[   22.991934][    T1]   SET = 0, FnV = 0
[   22.991934][    T1]   EA = 0, S1PTW = 0
[   22.991934][    T1]   FSC = 0x07: level 3 translation fault
[   22.991934][    T1] Data abort info:
[   22.991934][    T1]   ISV = 0, ISS = 0x00000007, ISS2 = 0x00000000
[   22.991934][    T1]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[   22.991934][    T1]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[   22.991934][    T1] [0000000109170ffc] user address but active_mm is swapper
[   22.991934][    T1] Internal error: Oops: 0000000096000007 [#1] PREEMPT SMP
[   22.991934][    T1] Dumping ftrace buffer:
[   22.991934][    T1]    (ftrace buffer empty)
[   22.991934][    T1] Modules linked in:
[   22.991934][    T1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.6.98-android15-8-g0b1d2aee7fc3-dirty-4k #1 688c7060a825a3ac418fe53881730b355915a419
[   22.991934][    T1] Hardware name: Unisoc UMS9360-base Board (DT)
[   22.991934][    T1] pstate: 804000c5 (Nzcv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[   22.991934][    T1] pc : swsusp_arch_resume+0x2ac/0x344
[   22.991934][    T1] lr : swsusp_arch_resume+0x294/0x344
[   22.991934][    T1] sp : ffffffc08006b960
[   22.991934][    T1] x29: ffffffc08006b9c0 x28: 0000000000000000 x27: 0000000000000000
[   22.991934][    T1] x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000820
[   22.991934][    T1] x23: ffffffd0817e3000 x22: ffffffd0817e3000 x21: 0000000000000000
[   22.991934][    T1] x20: ffffff8089171000 x19: ffffffd08252c8c8 x18: ffffffc080061058
[   22.991934][    T1] x17: 00000000529c6ef0 x16: 00000000529c6ef0 x15: 0000000000000004
[   22.991934][    T1] x14: ffffff8178c88000 x13: 0000000000000006 x12: 0000000000000000
[   22.991934][    T1] x11: 0000000000000015 x10: 0000000000000001 x9 : ffffffd082533000
[   22.991934][    T1] x8 : 0000000109171000 x7 : 205b5d3433393139 x6 : 392e32322020205b
[   22.991934][    T1] x5 : 000000010916f000 x4 : 000000008164b000 x3 : ffffff808a4e0530
[   22.991934][    T1] x2 : ffffffd08058e784 x1 : 0000000082326000 x0 : 000000010a283000
[   22.991934][    T1] Call trace:
[   22.991934][    T1]  swsusp_arch_resume+0x2ac/0x344
[   22.991934][    T1]  hibernation_restore+0x158/0x18c
[   22.991934][    T1]  load_image_and_restore+0xb0/0xec
[   22.991934][    T1]  software_resume+0xf4/0x19c
[   22.991934][    T1]  software_resume_initcall+0x34/0x78
[   22.991934][    T1]  do_one_initcall+0xe8/0x370
[   22.991934][    T1]  do_initcall_level+0xc8/0x19c
[   22.991934][    T1]  do_initcalls+0x70/0xc0
[   22.991934][    T1]  do_basic_setup+0x1c/0x28
[   22.991934][    T1]  kernel_init_freeable+0xe0/0x148
[   22.991934][    T1]  kernel_init+0x20/0x1a8
[   22.991934][    T1]  ret_from_fork+0x10/0x20
[   22.991934][    T1] Code: a9400a61 f94013e0 f9438923 f9400a64 (b85fc110)

Co-developed-by: Jeson Gao <jeson.gao@unisoc.com>
Signed-off-by: Jeson Gao <jeson.gao@unisoc.com>
Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: <stable@vger.kernel.org>
[catalin.marinas@arm.com: commit log updated by Mark Rutland]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregkh pushed a commit that referenced this pull request Jan 30, 2026
commit 90f9f5d upstream.

When creating a synthetic event based on an existing synthetic event that
had a stacktrace field and the new synthetic event used that field a
kernel crash occurred:

 ~# cd /sys/kernel/tracing
 ~# echo 's:stack unsigned long stack[];' > dynamic_events
 ~# echo 'hist:keys=prev_pid:s0=common_stacktrace if prev_state & 3' >> events/sched/sched_switch/trigger
 ~# echo 'hist:keys=next_pid:s1=$s0:onmatch(sched.sched_switch).trace(stack,$s1)' >> events/sched/sched_switch/trigger

The above creates a synthetic event that takes a stacktrace when a task
schedules out in a non-running state and passes that stacktrace to the
sched_switch event when that task schedules back in. It triggers the
"stack" synthetic event that has a stacktrace as its field (called "stack").

 ~# echo 's:syscall_stack s64 id; unsigned long stack[];' >> dynamic_events
 ~# echo 'hist:keys=common_pid:s2=stack' >> events/synthetic/stack/trigger
 ~# echo 'hist:keys=common_pid:s3=$s2,i0=id:onmatch(synthetic.stack).trace(syscall_stack,$i0,$s3)' >> events/raw_syscalls/sys_exit/trigger

The above makes another synthetic event called "syscall_stack" that
attaches the first synthetic event (stack) to the sys_exit trace event and
records the stacktrace from the stack event with the id of the system call
that is exiting.

When enabling this event (or using it in a historgram):

 ~# echo 1 > events/synthetic/syscall_stack/enable

Produces a kernel crash!

 BUG: unable to handle page fault for address: 0000000000400010
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 PGD 0 P4D 0
 Oops: Oops: 0000 [#1] SMP PTI
 CPU: 6 UID: 0 PID: 1257 Comm: bash Not tainted 6.16.3+deb14-amd64 #1 PREEMPT(lazy)  Debian 6.16.3-1
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.17.0-debian-1.17.0-1 04/01/2014
 RIP: 0010:trace_event_raw_event_synth+0x90/0x380
 Code: c5 00 00 00 00 85 d2 0f 84 e1 00 00 00 31 db eb 34 0f 1f 00 66 66 2e 0f 1f 84 00 00 00 00 00 66 66 2e 0f 1f 84 00 00 00 00 00 <49> 8b 04 24 48 83 c3 01 8d 0c c5 08 00 00 00 01 cd 41 3b 5d 40 0f
 RSP: 0018:ffffd2670388f958 EFLAGS: 00010202
 RAX: ffff8ba1065cc100 RBX: 0000000000000000 RCX: 0000000000000000
 RDX: 0000000000000001 RSI: fffff266ffda7b90 RDI: ffffd2670388f9b0
 RBP: 0000000000000010 R08: ffff8ba104e76000 R09: ffffd2670388fa50
 R10: ffff8ba102dd42e0 R11: ffffffff9a908970 R12: 0000000000400010
 R13: ffff8ba10a246400 R14: ffff8ba10a710220 R15: fffff266ffda7b90
 FS:  00007fa3bc63f740(0000) GS:ffff8ba2e0f48000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000400010 CR3: 0000000107f9e003 CR4: 0000000000172ef0
 Call Trace:
  <TASK>
  ? __tracing_map_insert+0x208/0x3a0
  action_trace+0x67/0x70
  event_hist_trigger+0x633/0x6d0
  event_triggers_call+0x82/0x130
  trace_event_buffer_commit+0x19d/0x250
  trace_event_raw_event_sys_exit+0x62/0xb0
  syscall_exit_work+0x9d/0x140
  do_syscall_64+0x20a/0x2f0
  ? trace_event_raw_event_sched_switch+0x12b/0x170
  ? save_fpregs_to_fpstate+0x3e/0x90
  ? _raw_spin_unlock+0xe/0x30
  ? finish_task_switch.isra.0+0x97/0x2c0
  ? __rseq_handle_notify_resume+0xad/0x4c0
  ? __schedule+0x4b8/0xd00
  ? restore_fpregs_from_fpstate+0x3c/0x90
  ? switch_fpu_return+0x5b/0xe0
  ? do_syscall_64+0x1ef/0x2f0
  ? do_fault+0x2e9/0x540
  ? __handle_mm_fault+0x7d1/0xf70
  ? count_memcg_events+0x167/0x1d0
  ? handle_mm_fault+0x1d7/0x2e0
  ? do_user_addr_fault+0x2c3/0x7f0
  entry_SYSCALL_64_after_hwframe+0x76/0x7e

The reason is that the stacktrace field is not labeled as such, and is
treated as a normal field and not as a dynamic event that it is.

In trace_event_raw_event_synth() the event is field is still treated as a
dynamic array, but the retrieval of the data is considered a normal field,
and the reference is just the meta data:

// Meta data is retrieved instead of a dynamic array
  str_val = (char *)(long)var_ref_vals[val_idx];

// Then when it tries to process it:
  len = *((unsigned long *)str_val) + 1;

It triggers a kernel page fault.

To fix this, first when defining the fields of the first synthetic event,
set the filter type to FILTER_STACKTRACE. This is used later by the second
synthetic event to know that this field is a stacktrace. When creating
the field of the new synthetic event, have it use this FILTER_STACKTRACE
to know to create a stacktrace field to copy the stacktrace into.

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Link: https://patch.msgid.link/20260122194824.6905a38e@gandalf.local.home
Fixes: 00cf3d6 ("tracing: Allow synthetic events to pass around stacktraces")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregkh pushed a commit that referenced this pull request Jan 30, 2026
[ Upstream commit 9910159 ]

When one iio device is a consumer of another, it is possible that
the ->info_exist_lock of both ends up being taken when reading the
value of the consumer device.

Since they currently belong to the same lockdep class (being
initialized in a single location with mutex_init()), that results in a
lockdep warning

         CPU0
         ----
    lock(&iio_dev_opaque->info_exist_lock);
    lock(&iio_dev_opaque->info_exist_lock);

   *** DEADLOCK ***

   May be due to missing lock nesting notation

  4 locks held by sensors/414:
   #0: c31fd6dc (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0x44/0x4e4
   #1: c4f5a1c4 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x1c/0xac
   #2: c2827548 (kn->active#34){.+.+}-{0:0}, at: kernfs_seq_start+0x30/0xac
   #3: c1dd2b6 (&iio_dev_opaque->info_exist_lock){+.+.}-{3:3}, at: iio_read_channel_processed_scale+0x24/0xd8

  stack backtrace:
  CPU: 0 UID: 0 PID: 414 Comm: sensors Not tainted 6.17.11 #5 NONE
  Hardware name: Generic AM33XX (Flattened Device Tree)
  Call trace:
   unwind_backtrace from show_stack+0x10/0x14
   show_stack from dump_stack_lvl+0x44/0x60
   dump_stack_lvl from print_deadlock_bug+0x2b8/0x334
   print_deadlock_bug from __lock_acquire+0x13a4/0x2ab0
   __lock_acquire from lock_acquire+0xd0/0x2c0
   lock_acquire from __mutex_lock+0xa0/0xe8c
   __mutex_lock from mutex_lock_nested+0x1c/0x24
   mutex_lock_nested from iio_read_channel_raw+0x20/0x6c
   iio_read_channel_raw from rescale_read_raw+0x128/0x1c4
   rescale_read_raw from iio_channel_read+0xe4/0xf4
   iio_channel_read from iio_read_channel_processed_scale+0x6c/0xd8
   iio_read_channel_processed_scale from iio_hwmon_read_val+0x68/0xbc
   iio_hwmon_read_val from dev_attr_show+0x18/0x48
   dev_attr_show from sysfs_kf_seq_show+0x80/0x110
   sysfs_kf_seq_show from seq_read_iter+0xdc/0x4e4
   seq_read_iter from vfs_read+0x238/0x2e4
   vfs_read from ksys_read+0x6c/0xec
   ksys_read from ret_fast_syscall+0x0/0x1c

Just as the mlock_key already has its own lockdep class, add a
lock_class_key for the info_exist mutex.

Note that this has in theory been a problem since before IIO first
left staging, but it only occurs when a chain of consumers is in use
and that is not often done.

Fixes: ac917a8 ("staging:iio:core set the iio_dev.info pointer to null on unregister under lock.")
Signed-off-by: Rasmus Villemoes <ravi@prevas.dk>
Reviewed-by: Peter Rosin <peda@axentia.se>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregkh pushed a commit that referenced this pull request Jan 30, 2026
commit 2515071 upstream.

The GET_INSTANCE_ID macro that caused a kernel panic when accessing sysfs
attributes:

1. Off-by-one error: The loop condition used '<=' instead of '<',
   causing access beyond array bounds. Since array indices are 0-based
   and go from 0 to instances_count-1, the loop should use '<'.

2. Missing NULL check: The code dereferenced attr_name_kobj->name
   without checking if attr_name_kobj was NULL, causing a null pointer
   dereference in min_length_show() and other attribute show functions.

The panic occurred when fwupd tried to read BIOS configuration attributes:

  Oops: general protection fault [#1] SMP KASAN NOPTI
  KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
  RIP: 0010:min_length_show+0xcf/0x1d0 [hp_bioscfg]

Add a NULL check for attr_name_kobj before dereferencing and corrects
the loop boundary to match the pattern used elsewhere in the driver.

Cc: stable@vger.kernel.org
Fixes: 5f94f18 ("platform/x86: hp-bioscfg: bioscfg-h")
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://patch.msgid.link/20260115203725.828434-3-mario.limonciello@amd.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregkh pushed a commit that referenced this pull request Jan 30, 2026
commit ca1a47c upstream.

Patch series "mm/hugetlb: fixes for PMD table sharing (incl.  using
mmu_gather)", v3.

One functional fix, one performance regression fix, and two related
comment fixes.

I cleaned up my prototype I recently shared [1] for the performance fix,
deferring most of the cleanups I had in the prototype to a later point.
While doing that I identified the other things.

The goal of this patch set is to be backported to stable trees "fairly"
easily. At least patch #1 and #4.

Patch #1 fixes hugetlb_pmd_shared() not detecting any sharing
Patch #2 + #3 are simple comment fixes that patch #4 interacts with.
Patch #4 is a fix for the reported performance regression due to excessive
IPI broadcasts during fork()+exit().

The last patch is all about TLB flushes, IPIs and mmu_gather.
Read: complicated

There are plenty of cleanups in the future to be had + one reasonable
optimization on x86. But that's all out of scope for this series.

Runtime tested, with a focus on fixing the performance regression using
the original reproducer [2] on x86.


This patch (of 4):

We switched from (wrongly) using the page count to an independent shared
count.  Now, shared page tables have a refcount of 1 (excluding
speculative references) and instead use ptdesc->pt_share_count to identify
sharing.

We didn't convert hugetlb_pmd_shared(), so right now, we would never
detect a shared PMD table as such, because sharing/unsharing no longer
touches the refcount of a PMD table.

Page migration, like mbind() or migrate_pages() would allow for migrating
folios mapped into such shared PMD tables, even though the folios are not
exclusive.  In smaps we would account them as "private" although they are
"shared", and we would be wrongly setting the PM_MMAP_EXCLUSIVE in the
pagemap interface.

Fix it by properly using ptdesc_pmd_is_shared() in hugetlb_pmd_shared().

Link: https://lkml.kernel.org/r/20251223214037.580860-1-david@kernel.org
Link: https://lkml.kernel.org/r/20251223214037.580860-2-david@kernel.org
Link: https://lore.kernel.org/all/8cab934d-4a56-44aa-b641-bfd7e23bd673@kernel.org/ [1]
Link: https://lore.kernel.org/all/8cab934d-4a56-44aa-b641-bfd7e23bd673@kernel.org/ [2]
Fixes: 59d9094 ("mm: hugetlb: independent PMD page table shared count")
Signed-off-by: David Hildenbrand (Red Hat) <david@kernel.org>
Reviewed-by: Rik van Riel <riel@surriel.com>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Tested-by: Lance Yang <lance.yang@linux.dev>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Tested-by: Laurence Oberman <loberman@redhat.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Acked-by: Oscar Salvador <osalvador@suse.de>
Cc: Liu Shixin <liushixin2@huawei.com>
Cc: Uschakow, Stanislav" <suschako@amazon.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregkh pushed a commit that referenced this pull request Jan 30, 2026
…gs list

[ Upstream commit b97d5ee ]

The netdevsim driver lacks a protection mechanism for operations on the
bpf_bound_progs list. When the nsim_bpf_create_prog() performs
list_add_tail, it is possible that nsim_bpf_destroy_prog() is
simultaneously performs list_del. Concurrent operations on the list may
lead to list corruption and trigger a kernel crash as follows:

[  417.290971] kernel BUG at lib/list_debug.c:62!
[  417.290983] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
[  417.290992] CPU: 10 PID: 168 Comm: kworker/10:1 Kdump: loaded Not tainted 6.19.0-rc5 #1
[  417.291003] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[  417.291007] Workqueue: events bpf_prog_free_deferred
[  417.291021] RIP: 0010:__list_del_entry_valid_or_report+0xa7/0xc0
[  417.291034] Code: a8 ff 0f 0b 48 89 fe 48 89 ca 48 c7 c7 48 a1 eb ae e8 ed fb a8 ff 0f 0b 48 89 fe 48 89 c2 48 c7 c7 80 a1 eb ae e8 d9 fb a8 ff <0f> 0b 48 89 d1 48 c7 c7 d0 a1 eb ae 48 89 f2 48 89 c6 e8 c2 fb a8
[  417.291040] RSP: 0018:ffffb16a40807df8 EFLAGS: 00010246
[  417.291046] RAX: 000000000000006d RBX: ffff8e589866f500 RCX: 0000000000000000
[  417.291051] RDX: 0000000000000000 RSI: ffff8e59f7b23180 RDI: ffff8e59f7b23180
[  417.291055] RBP: ffffb16a412c9000 R08: 0000000000000000 R09: 0000000000000003
[  417.291059] R10: ffffb16a40807c80 R11: ffffffffaf9edce8 R12: ffff8e594427ac20
[  417.291063] R13: ffff8e59f7b44780 R14: ffff8e58800b7a05 R15: 0000000000000000
[  417.291074] FS:  0000000000000000(0000) GS:ffff8e59f7b00000(0000) knlGS:0000000000000000
[  417.291079] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  417.291083] CR2: 00007fc4083efe08 CR3: 00000001c3626006 CR4: 0000000000770ee0
[  417.291088] PKRU: 55555554
[  417.291091] Call Trace:
[  417.291096]  <TASK>
[  417.291103]  nsim_bpf_destroy_prog+0x31/0x80 [netdevsim]
[  417.291154]  __bpf_prog_offload_destroy+0x2a/0x80
[  417.291163]  bpf_prog_dev_bound_destroy+0x6f/0xb0
[  417.291171]  bpf_prog_free_deferred+0x18e/0x1a0
[  417.291178]  process_one_work+0x18a/0x3a0
[  417.291188]  worker_thread+0x27b/0x3a0
[  417.291197]  ? __pfx_worker_thread+0x10/0x10
[  417.291207]  kthread+0xe5/0x120
[  417.291214]  ? __pfx_kthread+0x10/0x10
[  417.291221]  ret_from_fork+0x31/0x50
[  417.291230]  ? __pfx_kthread+0x10/0x10
[  417.291236]  ret_from_fork_asm+0x1a/0x30
[  417.291246]  </TASK>

Add a mutex lock, to prevent simultaneous addition and deletion operations
on the list.

Fixes: 31d3ad8 ("netdevsim: add bpf offload support")
Reported-by: Yinhao Hu <dddddd@hust.edu.cn>
Reported-by: Kaiyan Mei <M202472210@hust.edu.cn>
Signed-off-by: Yun Lu <luyun@kylinos.cn>
Link: https://patch.msgid.link/20260116095308.11441-1-luyun_611@163.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gregkh pushed a commit that referenced this pull request Jan 30, 2026
…itives

[ Upstream commit c06343b ]

The "valid" readout delay between the two reads of the watchdog is larger
than the valid delta between the resulting watchdog and clocksource
intervals, which results in false positive watchdog results.

Assume TSC is the clocksource and HPET is the watchdog and both have a
uncertainty margin of 250us (default). The watchdog readout does:

  1) wdnow = read(HPET);
  2) csnow = read(TSC);
  3) wdend = read(HPET);

The valid window for the delta between #1 and #3 is calculated by the
uncertainty margins of the watchdog and the clocksource:

   m = 2 * watchdog.uncertainty_margin + cs.uncertainty margin;

which results in 750us for the TSC/HPET case.

The actual interval comparison uses a smaller margin:

   m = watchdog.uncertainty_margin + cs.uncertainty margin;

which results in 500us for the TSC/HPET case.

That means the following scenario will trigger the watchdog:

 Watchdog cycle N:

 1)       wdnow[N] = read(HPET);
 2)       csnow[N] = read(TSC);
 3)       wdend[N] = read(HPET);

Assume the delay between #1 and #2 is 100us and the delay between #1 and

 Watchdog cycle N + 1:

 4)       wdnow[N + 1] = read(HPET);
 5)       csnow[N + 1] = read(TSC);
 6)       wdend[N + 1] = read(HPET);

If the delay between #4 and #6 is within the 750us margin then any delay
between #4 and #5 which is larger than 600us will fail the interval check
and mark the TSC unstable because the intervals are calculated against the
previous value:

    wd_int = wdnow[N + 1] - wdnow[N];
    cs_int = csnow[N + 1] - csnow[N];

Putting the above delays in place this results in:

    cs_int = (wdnow[N + 1] + 610us) - (wdnow[N] + 100us);
 -> cs_int = wd_int + 510us;

which is obviously larger than the allowed 500us margin and results in
marking TSC unstable.

Fix this by using the same margin as the interval comparison. If the delay
between two watchdog reads is larger than that, then the readout was either
disturbed by interconnect congestion, NMIs or SMIs.

Fixes: 4ac1dd3 ("clocksource: Set cs_watchdog_read() checks based on .uncertainty_margin")
Reported-by: Daniel J Blueman <daniel@quora.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/lkml/20250602223251.496591-1-daniel@quora.org/
Link: https://patch.msgid.link/87bjjxc9dq.ffs@tglx
Signed-off-by: Sasha Levin <sashal@kernel.org>
gregkh pushed a commit that referenced this pull request Jan 30, 2026
[ Upstream commit 27880b0 ]

tcf_ife_encode() must make sure ife_encode() does not return NULL.

syzbot reported:

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
 RIP: 0010:ife_tlv_meta_encode+0x41/0xa0 net/ife/ife.c:166
CPU: 3 UID: 0 PID: 8990 Comm: syz.0.696 Not tainted syzkaller #0 PREEMPT(full)
Call Trace:
 <TASK>
  ife_encode_meta_u32+0x153/0x180 net/sched/act_ife.c:101
  tcf_ife_encode net/sched/act_ife.c:841 [inline]
  tcf_ife_act+0x1022/0x1de0 net/sched/act_ife.c:877
  tc_act include/net/tc_wrapper.h:130 [inline]
  tcf_action_exec+0x1c0/0xa20 net/sched/act_api.c:1152
  tcf_exts_exec include/net/pkt_cls.h:349 [inline]
  mall_classify+0x1a0/0x2a0 net/sched/cls_matchall.c:42
  tc_classify include/net/tc_wrapper.h:197 [inline]
  __tcf_classify net/sched/cls_api.c:1764 [inline]
  tcf_classify+0x7f2/0x1380 net/sched/cls_api.c:1860
  multiq_classify net/sched/sch_multiq.c:39 [inline]
  multiq_enqueue+0xe0/0x510 net/sched/sch_multiq.c:66
  dev_qdisc_enqueue+0x45/0x250 net/core/dev.c:4147
  __dev_xmit_skb net/core/dev.c:4262 [inline]
  __dev_queue_xmit+0x2998/0x46c0 net/core/dev.c:4798

Fixes: 295a6e0 ("net/sched: act_ife: Change to use ife module")
Reported-by: syzbot+5cf914f193dffde3bd3c@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/6970d61d.050a0220.706b.0010.GAE@google.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Yotam Gigi <yotam.gi@gmail.com>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20260121133724.3400020-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gregkh pushed a commit that referenced this pull request Jan 30, 2026
[ Upstream commit 4a3dba4 ]

firmware populates MAC address, link modes (supported, advertised)
and EEPROM data in shared firmware structure which kernel access
via MAC block(CGX/RPM).

Accessing fwdata, on boards booted with out MAC block leading to
kernel panics.

Internal error: Oops: 0000000096000005 [#1]  SMP
[   10.460721] Modules linked in:
[   10.463779] CPU: 0 UID: 0 PID: 174 Comm: kworker/0:3 Not tainted 6.19.0-rc5-00154-g76ec646abdf7-dirty #3 PREEMPT
[   10.474045] Hardware name: Marvell OcteonTX CN98XX board (DT)
[   10.479793] Workqueue: events work_for_cpu_fn
[   10.484159] pstate: 80400009 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[   10.491124] pc : rvu_sdp_init+0x18/0x114
[   10.495051] lr : rvu_probe+0xe58/0x1d18

Fixes: 9978144 ("Octeontx2-af: Fetch MAC channel info from firmware")
Fixes: 5f21226 ("Octeontx2-pf: ethtool: support multi advertise mode")
Signed-off-by: Hariprasad Kelam <hkelam@marvell.com>
Link: https://patch.msgid.link/20260121094819.2566786-1-hkelam@marvell.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gregkh pushed a commit that referenced this pull request Jan 30, 2026
commit ea8ccfd upstream.

The code to restore a ZA context doesn't attempt to allocate the task's
sve_state before setting TIF_SME. Consequently, restoring a ZA context
can place a task into an invalid state where TIF_SME is set but the
task's sve_state is NULL.

In legitimate but uncommon cases where the ZA signal context was NOT
created by the kernel in the context of the same task (e.g. if the task
is saved/restored with something like CRIU), we have no guarantee that
sve_state had been allocated previously. In these cases, userspace can
enter streaming mode without trapping while sve_state is NULL, causing a
later NULL pointer dereference when the kernel attempts to store the
register state:

| # ./sigreturn-za
| Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
| Mem abort info:
|   ESR = 0x0000000096000046
|   EC = 0x25: DABT (current EL), IL = 32 bits
|   SET = 0, FnV = 0
|   EA = 0, S1PTW = 0
|   FSC = 0x06: level 2 translation fault
| Data abort info:
|   ISV = 0, ISS = 0x00000046, ISS2 = 0x00000000
|   CM = 0, WnR = 1, TnD = 0, TagAccess = 0
|   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
| user pgtable: 4k pages, 52-bit VAs, pgdp=0000000101f47c00
| [0000000000000000] pgd=08000001021d8403, p4d=0800000102274403, pud=0800000102275403, pmd=0000000000000000
| Internal error: Oops: 0000000096000046 [#1]  SMP
| Modules linked in:
| CPU: 0 UID: 0 PID: 153 Comm: sigreturn-za Not tainted 6.19.0-rc1 #1 PREEMPT
| Hardware name: linux,dummy-virt (DT)
| pstate: 214000c9 (nzCv daIF +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
| pc : sve_save_state+0x4/0xf0
| lr : fpsimd_save_user_state+0xb0/0x1c0
| sp : ffff80008070bcc0
| x29: ffff80008070bcc0 x28: fff00000c1ca4c40 x27: 63cfa172fb5cf658
| x26: fff00000c1ca5228 x25: 0000000000000000 x24: 0000000000000000
| x23: 0000000000000000 x22: fff00000c1ca4c40 x21: fff00000c1ca4c40
| x20: 0000000000000020 x19: fff00000ff6900f0 x18: 0000000000000000
| x17: fff05e8e0311f000 x16: 0000000000000000 x15: 028fca8f3bdaf21c
| x14: 0000000000000212 x13: fff00000c0209f10 x12: 0000000000000020
| x11: 0000000000200b20 x10: 0000000000000000 x9 : fff00000ff69dcc0
| x8 : 00000000000003f2 x7 : 0000000000000001 x6 : fff00000c1ca5b48
| x5 : fff05e8e0311f000 x4 : 0000000008000000 x3 : 0000000000000000
| x2 : 0000000000000001 x1 : fff00000c1ca5970 x0 : 0000000000000440
| Call trace:
|  sve_save_state+0x4/0xf0 (P)
|  fpsimd_thread_switch+0x48/0x198
|  __switch_to+0x20/0x1c0
|  __schedule+0x36c/0xce0
|  schedule+0x34/0x11c
|  exit_to_user_mode_loop+0x124/0x188
|  el0_interrupt+0xc8/0xd8
|  __el0_irq_handler_common+0x18/0x24
|  el0t_64_irq_handler+0x10/0x1c
|  el0t_64_irq+0x198/0x19c
| Code: 54000040 d51b4408 d65f03c0 d503245f (e5bb5800)
| ---[ end trace 0000000000000000 ]---

Fix this by having restore_za_context() ensure that the task's sve_state
is allocated, matching what we do when taking an SME trap. Any live
SVE/SSVE state (which is restored earlier from a separate signal
context) must be preserved, and hence this is not zeroed.

Fixes: 3978221 ("arm64/sme: Implement ZA signal handling")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: <stable@vger.kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregkh pushed a commit that referenced this pull request Jan 30, 2026
commit e2f8216 upstream.

A DABT is reported[1] on an android based system when resume from hiberate.
This happens because swsusp_arch_suspend_exit() is marked with SYM_CODE_*()
and does not have a CFI hash, but swsusp_arch_resume() will attempt to
verify the CFI hash when calling a copy of swsusp_arch_suspend_exit().

Given that there's an existing requirement that the entrypoint to
swsusp_arch_suspend_exit() is the first byte of the .hibernate_exit.text
section, we cannot fix this by marking swsusp_arch_suspend_exit() with
SYM_FUNC_*(). The simplest fix for now is to disable the CFI check in
swsusp_arch_resume().

Mark swsusp_arch_resume() as __nocfi to disable the CFI check.

[1]
[   22.991934][    T1] Unable to handle kernel paging request at virtual address 0000000109170ffc
[   22.991934][    T1] Mem abort info:
[   22.991934][    T1]   ESR = 0x0000000096000007
[   22.991934][    T1]   EC = 0x25: DABT (current EL), IL = 32 bits
[   22.991934][    T1]   SET = 0, FnV = 0
[   22.991934][    T1]   EA = 0, S1PTW = 0
[   22.991934][    T1]   FSC = 0x07: level 3 translation fault
[   22.991934][    T1] Data abort info:
[   22.991934][    T1]   ISV = 0, ISS = 0x00000007, ISS2 = 0x00000000
[   22.991934][    T1]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[   22.991934][    T1]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[   22.991934][    T1] [0000000109170ffc] user address but active_mm is swapper
[   22.991934][    T1] Internal error: Oops: 0000000096000007 [#1] PREEMPT SMP
[   22.991934][    T1] Dumping ftrace buffer:
[   22.991934][    T1]    (ftrace buffer empty)
[   22.991934][    T1] Modules linked in:
[   22.991934][    T1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.6.98-android15-8-g0b1d2aee7fc3-dirty-4k #1 688c7060a825a3ac418fe53881730b355915a419
[   22.991934][    T1] Hardware name: Unisoc UMS9360-base Board (DT)
[   22.991934][    T1] pstate: 804000c5 (Nzcv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[   22.991934][    T1] pc : swsusp_arch_resume+0x2ac/0x344
[   22.991934][    T1] lr : swsusp_arch_resume+0x294/0x344
[   22.991934][    T1] sp : ffffffc08006b960
[   22.991934][    T1] x29: ffffffc08006b9c0 x28: 0000000000000000 x27: 0000000000000000
[   22.991934][    T1] x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000820
[   22.991934][    T1] x23: ffffffd0817e3000 x22: ffffffd0817e3000 x21: 0000000000000000
[   22.991934][    T1] x20: ffffff8089171000 x19: ffffffd08252c8c8 x18: ffffffc080061058
[   22.991934][    T1] x17: 00000000529c6ef0 x16: 00000000529c6ef0 x15: 0000000000000004
[   22.991934][    T1] x14: ffffff8178c88000 x13: 0000000000000006 x12: 0000000000000000
[   22.991934][    T1] x11: 0000000000000015 x10: 0000000000000001 x9 : ffffffd082533000
[   22.991934][    T1] x8 : 0000000109171000 x7 : 205b5d3433393139 x6 : 392e32322020205b
[   22.991934][    T1] x5 : 000000010916f000 x4 : 000000008164b000 x3 : ffffff808a4e0530
[   22.991934][    T1] x2 : ffffffd08058e784 x1 : 0000000082326000 x0 : 000000010a283000
[   22.991934][    T1] Call trace:
[   22.991934][    T1]  swsusp_arch_resume+0x2ac/0x344
[   22.991934][    T1]  hibernation_restore+0x158/0x18c
[   22.991934][    T1]  load_image_and_restore+0xb0/0xec
[   22.991934][    T1]  software_resume+0xf4/0x19c
[   22.991934][    T1]  software_resume_initcall+0x34/0x78
[   22.991934][    T1]  do_one_initcall+0xe8/0x370
[   22.991934][    T1]  do_initcall_level+0xc8/0x19c
[   22.991934][    T1]  do_initcalls+0x70/0xc0
[   22.991934][    T1]  do_basic_setup+0x1c/0x28
[   22.991934][    T1]  kernel_init_freeable+0xe0/0x148
[   22.991934][    T1]  kernel_init+0x20/0x1a8
[   22.991934][    T1]  ret_from_fork+0x10/0x20
[   22.991934][    T1] Code: a9400a61 f94013e0 f9438923 f9400a64 (b85fc110)

Co-developed-by: Jeson Gao <jeson.gao@unisoc.com>
Signed-off-by: Jeson Gao <jeson.gao@unisoc.com>
Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: <stable@vger.kernel.org>
[catalin.marinas@arm.com: commit log updated by Mark Rutland]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregkh pushed a commit that referenced this pull request Jan 30, 2026
commit 90f9f5d upstream.

When creating a synthetic event based on an existing synthetic event that
had a stacktrace field and the new synthetic event used that field a
kernel crash occurred:

 ~# cd /sys/kernel/tracing
 ~# echo 's:stack unsigned long stack[];' > dynamic_events
 ~# echo 'hist:keys=prev_pid:s0=common_stacktrace if prev_state & 3' >> events/sched/sched_switch/trigger
 ~# echo 'hist:keys=next_pid:s1=$s0:onmatch(sched.sched_switch).trace(stack,$s1)' >> events/sched/sched_switch/trigger

The above creates a synthetic event that takes a stacktrace when a task
schedules out in a non-running state and passes that stacktrace to the
sched_switch event when that task schedules back in. It triggers the
"stack" synthetic event that has a stacktrace as its field (called "stack").

 ~# echo 's:syscall_stack s64 id; unsigned long stack[];' >> dynamic_events
 ~# echo 'hist:keys=common_pid:s2=stack' >> events/synthetic/stack/trigger
 ~# echo 'hist:keys=common_pid:s3=$s2,i0=id:onmatch(synthetic.stack).trace(syscall_stack,$i0,$s3)' >> events/raw_syscalls/sys_exit/trigger

The above makes another synthetic event called "syscall_stack" that
attaches the first synthetic event (stack) to the sys_exit trace event and
records the stacktrace from the stack event with the id of the system call
that is exiting.

When enabling this event (or using it in a historgram):

 ~# echo 1 > events/synthetic/syscall_stack/enable

Produces a kernel crash!

 BUG: unable to handle page fault for address: 0000000000400010
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 PGD 0 P4D 0
 Oops: Oops: 0000 [#1] SMP PTI
 CPU: 6 UID: 0 PID: 1257 Comm: bash Not tainted 6.16.3+deb14-amd64 #1 PREEMPT(lazy)  Debian 6.16.3-1
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.17.0-debian-1.17.0-1 04/01/2014
 RIP: 0010:trace_event_raw_event_synth+0x90/0x380
 Code: c5 00 00 00 00 85 d2 0f 84 e1 00 00 00 31 db eb 34 0f 1f 00 66 66 2e 0f 1f 84 00 00 00 00 00 66 66 2e 0f 1f 84 00 00 00 00 00 <49> 8b 04 24 48 83 c3 01 8d 0c c5 08 00 00 00 01 cd 41 3b 5d 40 0f
 RSP: 0018:ffffd2670388f958 EFLAGS: 00010202
 RAX: ffff8ba1065cc100 RBX: 0000000000000000 RCX: 0000000000000000
 RDX: 0000000000000001 RSI: fffff266ffda7b90 RDI: ffffd2670388f9b0
 RBP: 0000000000000010 R08: ffff8ba104e76000 R09: ffffd2670388fa50
 R10: ffff8ba102dd42e0 R11: ffffffff9a908970 R12: 0000000000400010
 R13: ffff8ba10a246400 R14: ffff8ba10a710220 R15: fffff266ffda7b90
 FS:  00007fa3bc63f740(0000) GS:ffff8ba2e0f48000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000400010 CR3: 0000000107f9e003 CR4: 0000000000172ef0
 Call Trace:
  <TASK>
  ? __tracing_map_insert+0x208/0x3a0
  action_trace+0x67/0x70
  event_hist_trigger+0x633/0x6d0
  event_triggers_call+0x82/0x130
  trace_event_buffer_commit+0x19d/0x250
  trace_event_raw_event_sys_exit+0x62/0xb0
  syscall_exit_work+0x9d/0x140
  do_syscall_64+0x20a/0x2f0
  ? trace_event_raw_event_sched_switch+0x12b/0x170
  ? save_fpregs_to_fpstate+0x3e/0x90
  ? _raw_spin_unlock+0xe/0x30
  ? finish_task_switch.isra.0+0x97/0x2c0
  ? __rseq_handle_notify_resume+0xad/0x4c0
  ? __schedule+0x4b8/0xd00
  ? restore_fpregs_from_fpstate+0x3c/0x90
  ? switch_fpu_return+0x5b/0xe0
  ? do_syscall_64+0x1ef/0x2f0
  ? do_fault+0x2e9/0x540
  ? __handle_mm_fault+0x7d1/0xf70
  ? count_memcg_events+0x167/0x1d0
  ? handle_mm_fault+0x1d7/0x2e0
  ? do_user_addr_fault+0x2c3/0x7f0
  entry_SYSCALL_64_after_hwframe+0x76/0x7e

The reason is that the stacktrace field is not labeled as such, and is
treated as a normal field and not as a dynamic event that it is.

In trace_event_raw_event_synth() the event is field is still treated as a
dynamic array, but the retrieval of the data is considered a normal field,
and the reference is just the meta data:

// Meta data is retrieved instead of a dynamic array
  str_val = (char *)(long)var_ref_vals[val_idx];

// Then when it tries to process it:
  len = *((unsigned long *)str_val) + 1;

It triggers a kernel page fault.

To fix this, first when defining the fields of the first synthetic event,
set the filter type to FILTER_STACKTRACE. This is used later by the second
synthetic event to know that this field is a stacktrace. When creating
the field of the new synthetic event, have it use this FILTER_STACKTRACE
to know to create a stacktrace field to copy the stacktrace into.

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Link: https://patch.msgid.link/20260122194824.6905a38e@gandalf.local.home
Fixes: 00cf3d6 ("tracing: Allow synthetic events to pass around stacktraces")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregkh pushed a commit that referenced this pull request Jan 30, 2026
[ Upstream commit 9910159 ]

When one iio device is a consumer of another, it is possible that
the ->info_exist_lock of both ends up being taken when reading the
value of the consumer device.

Since they currently belong to the same lockdep class (being
initialized in a single location with mutex_init()), that results in a
lockdep warning

         CPU0
         ----
    lock(&iio_dev_opaque->info_exist_lock);
    lock(&iio_dev_opaque->info_exist_lock);

   *** DEADLOCK ***

   May be due to missing lock nesting notation

  4 locks held by sensors/414:
   #0: c31fd6dc (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0x44/0x4e4
   #1: c4f5a1c4 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x1c/0xac
   #2: c2827548 (kn->active#34){.+.+}-{0:0}, at: kernfs_seq_start+0x30/0xac
   #3: c1dd2b6 (&iio_dev_opaque->info_exist_lock){+.+.}-{3:3}, at: iio_read_channel_processed_scale+0x24/0xd8

  stack backtrace:
  CPU: 0 UID: 0 PID: 414 Comm: sensors Not tainted 6.17.11 #5 NONE
  Hardware name: Generic AM33XX (Flattened Device Tree)
  Call trace:
   unwind_backtrace from show_stack+0x10/0x14
   show_stack from dump_stack_lvl+0x44/0x60
   dump_stack_lvl from print_deadlock_bug+0x2b8/0x334
   print_deadlock_bug from __lock_acquire+0x13a4/0x2ab0
   __lock_acquire from lock_acquire+0xd0/0x2c0
   lock_acquire from __mutex_lock+0xa0/0xe8c
   __mutex_lock from mutex_lock_nested+0x1c/0x24
   mutex_lock_nested from iio_read_channel_raw+0x20/0x6c
   iio_read_channel_raw from rescale_read_raw+0x128/0x1c4
   rescale_read_raw from iio_channel_read+0xe4/0xf4
   iio_channel_read from iio_read_channel_processed_scale+0x6c/0xd8
   iio_read_channel_processed_scale from iio_hwmon_read_val+0x68/0xbc
   iio_hwmon_read_val from dev_attr_show+0x18/0x48
   dev_attr_show from sysfs_kf_seq_show+0x80/0x110
   sysfs_kf_seq_show from seq_read_iter+0xdc/0x4e4
   seq_read_iter from vfs_read+0x238/0x2e4
   vfs_read from ksys_read+0x6c/0xec
   ksys_read from ret_fast_syscall+0x0/0x1c

Just as the mlock_key already has its own lockdep class, add a
lock_class_key for the info_exist mutex.

Note that this has in theory been a problem since before IIO first
left staging, but it only occurs when a chain of consumers is in use
and that is not often done.

Fixes: ac917a8 ("staging:iio:core set the iio_dev.info pointer to null on unregister under lock.")
Signed-off-by: Rasmus Villemoes <ravi@prevas.dk>
Reviewed-by: Peter Rosin <peda@axentia.se>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tiala pushed a commit to tiala/linux-sa that referenced this pull request Feb 1, 2026
gregkh pushed a commit that referenced this pull request Feb 2, 2026
There was a lockdep warning in sprd_gpio:

[    6.258269][T329@C6] [ BUG: Invalid wait context ]
[    6.258270][T329@C6] 6.18.0-android17-0-g30527ad7aaae-ab00009-4k #1 Tainted: G        W  OE
[    6.258272][T329@C6] -----------------------------
[    6.258273][T329@C6] modprobe/329 is trying to lock:
[    6.258275][T329@C6] ffffff8081c91690 (&sprd_gpio->lock){....}-{3:3}, at: sprd_gpio_irq_unmask+0x4c/0xa4 [gpio_sprd]
[    6.258282][T329@C6] other info that might help us debug this:
[    6.258283][T329@C6] context-{5:5}
[    6.258285][T329@C6] 3 locks held by modprobe/329:
[    6.258286][T329@C6]  #0: ffffff808baca108 (&dev->mutex){....}-{4:4}, at: __driver_attach+0xc4/0x204
[    6.258295][T329@C6]  #1: ffffff80965e7240 (request_class#4){+.+.}-{4:4}, at: __setup_irq+0x1cc/0x82c
[    6.258304][T329@C6]  #2: ffffff80965e70c8 (lock_class#4){....}-{2:2}, at: __setup_irq+0x21c/0x82c
[    6.258313][T329@C6] stack backtrace:
[    6.258314][T329@C6] CPU: 6 UID: 0 PID: 329 Comm: modprobe Tainted: G        W  OE       6.18.0-android17-0-g30527ad7aaae-ab00009-4k #1 PREEMPT  3ad5b0f45741a16e5838da790706e16ceb6717df
[    6.258316][T329@C6] Tainted: [W]=WARN, [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
[    6.258317][T329@C6] Hardware name: Unisoc UMS9632-base Board (DT)
[    6.258318][T329@C6] Call trace:
[    6.258318][T329@C6]  show_stack+0x20/0x30 (C)
[    6.258321][T329@C6]  __dump_stack+0x28/0x3c
[    6.258324][T329@C6]  dump_stack_lvl+0xac/0xf0
[    6.258326][T329@C6]  dump_stack+0x18/0x3c
[    6.258329][T329@C6]  __lock_acquire+0x824/0x2c28
[    6.258331][T329@C6]  lock_acquire+0x148/0x2cc
[    6.258333][T329@C6]  _raw_spin_lock_irqsave+0x6c/0xb4
[    6.258334][T329@C6]  sprd_gpio_irq_unmask+0x4c/0xa4 [gpio_sprd 814535e93c6d8e0853c45c02eab0fa88a9da6487]
[    6.258337][T329@C6]  irq_startup+0x238/0x350
[    6.258340][T329@C6]  __setup_irq+0x504/0x82c
[    6.258342][T329@C6]  request_threaded_irq+0x118/0x184
[    6.258344][T329@C6]  devm_request_threaded_irq+0x94/0x120
[    6.258347][T329@C6]  sc8546_init_irq+0x114/0x170 [sc8546_charger 223586ccafc27439f7db4f95b0c8e6e882349a99]
[    6.258352][T329@C6]  sc8546_charger_probe+0x53c/0x5a0 [sc8546_charger 223586ccafc27439f7db4f95b0c8e6e882349a99]
[    6.258358][T329@C6]  i2c_device_probe+0x2c8/0x350
[    6.258361][T329@C6]  really_probe+0x1a8/0x46c
[    6.258363][T329@C6]  __driver_probe_device+0xa4/0x10c
[    6.258366][T329@C6]  driver_probe_device+0x44/0x1b4
[    6.258369][T329@C6]  __driver_attach+0xd0/0x204
[    6.258371][T329@C6]  bus_for_each_dev+0x10c/0x168
[    6.258373][T329@C6]  driver_attach+0x2c/0x3c
[    6.258376][T329@C6]  bus_add_driver+0x154/0x29c
[    6.258378][T329@C6]  driver_register+0x70/0x10c
[    6.258381][T329@C6]  i2c_register_driver+0x48/0xc8
[    6.258384][T329@C6]  init_module+0x28/0xfd8 [sc8546_charger 223586ccafc27439f7db4f95b0c8e6e882349a99]
[    6.258389][T329@C6]  do_one_initcall+0x128/0x42c
[    6.258392][T329@C6]  do_init_module+0x60/0x254
[    6.258395][T329@C6]  load_module+0x1054/0x1220
[    6.258397][T329@C6]  __arm64_sys_finit_module+0x240/0x35c
[    6.258400][T329@C6]  invoke_syscall+0x60/0xec
[    6.258402][T329@C6]  el0_svc_common+0xb0/0xe4
[    6.258405][T329@C6]  do_el0_svc+0x24/0x30
[    6.258407][T329@C6]  el0_svc+0x54/0x1c4
[    6.258409][T329@C6]  el0t_64_sync_handler+0x68/0xdc
[    6.258411][T329@C6]  el0t_64_sync+0x1c4/0x1c8

This is because the spin_lock would change to rt_mutex in PREEMPT_RT,
however the sprd_gpio->lock would use in hard-irq, this is unsafe.

So change the spin_lock_t to raw_spin_lock_t to use the spinlock
in hard-irq.

Signed-off-by: Xuewen Yan <xuewen.yan@unisoc.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20260126094209.9855-1-xuewen.yan@unisoc.com
[Bartosz: tweaked the commit message]
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
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9 participants