| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
net: mscc: ocelot: add missing lock protection in ocelot_port_xmit_inj()
ocelot_port_xmit_inj() calls ocelot_can_inject() and
ocelot_port_inject_frame() without holding the injection group lock.
Both functions contain lockdep_assert_held() for the injection lock,
and the correct caller felix_port_deferred_xmit() properly acquires
the lock using ocelot_lock_inj_grp() before calling these functions.
Add ocelot_lock_inj_grp()/ocelot_unlock_inj_grp() around the register
injection path to fix the missing lock protection. The FDMA path is not
affected as it uses its own locking mechanism. |
| In the Linux kernel, the following vulnerability has been resolved:
fs/ntfs3: fix deadlock in ni_read_folio_cmpr
Syzbot reported a task hung in ni_readpage_cmpr (now ni_read_folio_cmpr).
This is caused by a lock inversion deadlock involving the inode mutex
(ni_lock) and page locks.
Scenario:
1. Task A enters ntfs_read_folio() for page X. It acquires ni_lock.
2. Task A calls ni_read_folio_cmpr(), which attempts to lock all pages in
the compressed frame (including page Y).
3. Concurrently, Task B (e.g., via readahead) has locked page Y and
calls ntfs_read_folio().
4. Task B waits for ni_lock (held by A).
5. Task A waits for page Y lock (held by B).
-> DEADLOCK.
The fix is to restructure locking: do not take ni_lock in ntfs_read_folio().
Instead, acquire ni_lock inside ni_read_folio_cmpr() ONLY AFTER all required
page locks for the frame have been successfully acquired. This restores the
correct lock ordering (Page Lock -> ni_lock) consistent with VFS.
[almaz.alexandrovich@paragon-software.com: ni_readpage_cmpr was renamed to ni_read_folio_cmpr] |
| In the Linux kernel, the following vulnerability has been resolved:
batman-adv: Avoid double-rtnl_lock ELP metric worker
batadv_v_elp_get_throughput() might be called when the RTNL lock is already
held. This could be problematic when the work queue item is cancelled via
cancel_delayed_work_sync() in batadv_v_elp_iface_disable(). In this case,
an rtnl_lock() would cause a deadlock.
To avoid this, rtnl_trylock() was used in this function to skip the
retrieval of the ethtool information in case the RTNL lock was already
held.
But for cfg80211 interfaces, batadv_get_real_netdev() was called - which
also uses rtnl_lock(). The approach for __ethtool_get_link_ksettings() must
also be used instead and the lockless version __batadv_get_real_netdev()
has to be called. |
| In the Linux kernel, the following vulnerability has been resolved:
perf/core: Fix invalid wait context in ctx_sched_in()
Lockdep found a bug in the event scheduling when a pinned event was
failed and wakes up the threads in the ring buffer like below.
It seems it should not grab a wait-queue lock under perf-context lock.
Let's do it with irq_work.
[ 39.913691] =============================
[ 39.914157] [ BUG: Invalid wait context ]
[ 39.914623] 6.15.0-next-20250530-next-2025053 #1 Not tainted
[ 39.915271] -----------------------------
[ 39.915731] repro/837 is trying to lock:
[ 39.916191] ffff88801acfabd8 (&event->waitq){....}-{3:3}, at: __wake_up+0x26/0x60
[ 39.917182] other info that might help us debug this:
[ 39.917761] context-{5:5}
[ 39.918079] 4 locks held by repro/837:
[ 39.918530] #0: ffffffff8725cd00 (rcu_read_lock){....}-{1:3}, at: __perf_event_task_sched_in+0xd1/0xbc0
[ 39.919612] #1: ffff88806ca3c6f8 (&cpuctx_lock){....}-{2:2}, at: __perf_event_task_sched_in+0x1a7/0xbc0
[ 39.920748] #2: ffff88800d91fc18 (&ctx->lock){....}-{2:2}, at: __perf_event_task_sched_in+0x1f9/0xbc0
[ 39.921819] #3: ffffffff8725cd00 (rcu_read_lock){....}-{1:3}, at: perf_event_wakeup+0x6c/0x470 |
| In the Linux kernel, the following vulnerability has been resolved:
drm/imagination: Fix deadlock in soft reset sequence
The soft reset sequence is currently executed from the threaded IRQ
handler, hence it cannot call disable_irq() which internally waits
for IRQ handlers, i.e. itself, to complete.
Use disable_irq_nosync() during a soft reset instead. |
| In the Linux kernel, the following vulnerability has been resolved:
mm: Fix a hmm_range_fault() livelock / starvation problem
If hmm_range_fault() fails a folio_trylock() in do_swap_page,
trying to acquire the lock of a device-private folio for migration,
to ram, the function will spin until it succeeds grabbing the lock.
However, if the process holding the lock is depending on a work
item to be completed, which is scheduled on the same CPU as the
spinning hmm_range_fault(), that work item might be starved and
we end up in a livelock / starvation situation which is never
resolved.
This can happen, for example if the process holding the
device-private folio lock is stuck in
migrate_device_unmap()->lru_add_drain_all()
sinc lru_add_drain_all() requires a short work-item
to be run on all online cpus to complete.
A prerequisite for this to happen is:
a) Both zone device and system memory folios are considered in
migrate_device_unmap(), so that there is a reason to call
lru_add_drain_all() for a system memory folio while a
folio lock is held on a zone device folio.
b) The zone device folio has an initial mapcount > 1 which causes
at least one migration PTE entry insertion to be deferred to
try_to_migrate(), which can happen after the call to
lru_add_drain_all().
c) No or voluntary only preemption.
This all seems pretty unlikely to happen, but indeed is hit by
the "xe_exec_system_allocator" igt test.
Resolve this by waiting for the folio to be unlocked if the
folio_trylock() fails in do_swap_page().
Rename migration_entry_wait_on_locked() to
softleaf_entry_wait_unlock() and update its documentation to
indicate the new use-case.
Future code improvements might consider moving
the lru_add_drain_all() call in migrate_device_unmap() to be
called *after* all pages have migration entries inserted.
That would eliminate also b) above.
v2:
- Instead of a cond_resched() in hmm_range_fault(),
eliminate the problem by waiting for the folio to be unlocked
in do_swap_page() (Alistair Popple, Andrew Morton)
v3:
- Add a stub migration_entry_wait_on_locked() for the
!CONFIG_MIGRATION case. (Kernel Test Robot)
v4:
- Rename migrate_entry_wait_on_locked() to
softleaf_entry_wait_on_locked() and update docs (Alistair Popple)
v5:
- Add a WARN_ON_ONCE() for the !CONFIG_MIGRATION
version of softleaf_entry_wait_on_locked().
- Modify wording around function names in the commit message
(Andrew Morton)
(cherry picked from commit a69d1ab971a624c6f112cea61536569d579c3215) |
| In the Linux kernel, the following vulnerability has been resolved:
accel/amdxdna: Fix runtime suspend deadlock when there is pending job
The runtime suspend callback drains the running job workqueue before
suspending the device. If a job is still executing and calls
pm_runtime_resume_and_get(), it can deadlock with the runtime suspend
path.
Fix this by moving pm_runtime_resume_and_get() from the job execution
routine to the job submission routine, ensuring the device is resumed
before the job is queued and avoiding the deadlock during runtime
suspend. |
| In the Linux kernel, the following vulnerability has been resolved:
sched_ext: Fix SCX_KICK_WAIT deadlock by deferring wait to balance callback
SCX_KICK_WAIT busy-waits in kick_cpus_irq_workfn() using
smp_cond_load_acquire() until the target CPU's kick_sync advances. Because
the irq_work runs in hardirq context, the waiting CPU cannot reschedule and
its own kick_sync never advances. If multiple CPUs form a wait cycle, all
CPUs deadlock.
Replace the busy-wait in kick_cpus_irq_workfn() with resched_curr() to
force the CPU through do_pick_task_scx(), which queues a balance callback
to perform the wait. The balance callback drops the rq lock and enables
IRQs following the sched_core_balance() pattern, so the CPU can process
IPIs while waiting. The local CPU's kick_sync is advanced on entry to
do_pick_task_scx() and continuously during the wait, ensuring any CPU that
starts waiting for us sees the advancement and cannot form cyclic
dependencies. |
| In the Linux kernel, the following vulnerability has been resolved:
USB: dummy-hcd: Fix locking/synchronization error
Syzbot testing was able to provoke an addressing exception and crash
in the usb_gadget_udc_reset() routine in
drivers/usb/gadgets/udc/core.c, resulting from the fact that the
routine was called with a second ("driver") argument of NULL. The bad
caller was set_link_state() in dummy_hcd.c, and the problem arose
because of a race between a USB reset and driver unbind.
These sorts of races were not supposed to be possible; commit
7dbd8f4cabd9 ("USB: dummy-hcd: Fix erroneous synchronization change"),
along with a few followup commits, was written specifically to prevent
them. As it turns out, there are (at least) two errors remaining in
the code. Another patch will address the second error; this one is
concerned with the first.
The error responsible for the syzbot crash occurred because the
stop_activity() routine will sometimes drop and then re-acquire the
dum->lock spinlock. A call to stop_activity() occurs in
set_link_state() when handling an emulated USB reset, after the test
of dum->ints_enabled and before the increment of dum->callback_usage.
This allowed another thread (doing a driver unbind) to sneak in and
grab the spinlock, and then clear dum->ints_enabled and dum->driver.
Normally this other thread would have to wait for dum->callback_usage
to go down to 0 before it would clear dum->driver, but in this case it
didn't have to wait since dum->callback_usage had not yet been
incremented.
The fix is to increment dum->callback_usage _before_ calling
stop_activity() instead of after. Then the thread doing the unbind
will not clear dum->driver until after the call to
usb_gadget_udc_reset() safely returns and dum->callback_usage has been
decremented again. |
| In the Linux kernel, the following vulnerability has been resolved:
octeontx2-af: Workaround SQM/PSE stalls by disabling sticky
NIX SQ manager sticky mode is known to cause stalls when multiple SQs
share an SMQ and transmit concurrently. Additionally, PSE may deadlock
on transitions between sticky and non-sticky transmissions. There is
also a credit drop issue observed when certain condition clocks are
gated.
work around these hardware errata by:
- Disabling SQM sticky operation:
- Clear TM6 (bit 15)
- Clear TM11 (bit 14)
- Disabling sticky → non-sticky transition path that can deadlock PSE:
- Clear TM5 (bit 23)
- Preventing credit drops by keeping the control-flow clock enabled:
- Set TM9 (bit 21)
These changes are applied via NIX_AF_SQM_DBG_CTL_STATUS. With this
configuration the SQM/PSE maintain forward progress under load without
credit loss, at the cost of disabling sticky optimizations. |
| In the Linux kernel, the following vulnerability has been resolved:
mm: slub: avoid wake up kswapd in set_track_prepare
set_track_prepare() can incur lock recursion.
The issue is that it is called from hrtimer_start_range_ns
holding the per_cpu(hrtimer_bases)[n].lock, but when enabled
CONFIG_DEBUG_OBJECTS_TIMERS, may wake up kswapd in set_track_prepare,
and try to hold the per_cpu(hrtimer_bases)[n].lock.
Avoid deadlock caused by implicitly waking up kswapd by passing in
allocation flags, which do not contain __GFP_KSWAPD_RECLAIM in the
debug_objects_fill_pool() case. Inside stack depot they are processed by
gfp_nested_mask().
Since ___slab_alloc() has preemption disabled, we mask out
__GFP_DIRECT_RECLAIM from the flags there.
The oops looks something like:
BUG: spinlock recursion on CPU#3, swapper/3/0
lock: 0xffffff8a4bf29c80, .magic: dead4ead, .owner: swapper/3/0, .owner_cpu: 3
Hardware name: Qualcomm Technologies, Inc. Popsicle based on SM8850 (DT)
Call trace:
spin_bug+0x0
_raw_spin_lock_irqsave+0x80
hrtimer_try_to_cancel+0x94
task_contending+0x10c
enqueue_dl_entity+0x2a4
dl_server_start+0x74
enqueue_task_fair+0x568
enqueue_task+0xac
do_activate_task+0x14c
ttwu_do_activate+0xcc
try_to_wake_up+0x6c8
default_wake_function+0x20
autoremove_wake_function+0x1c
__wake_up+0xac
wakeup_kswapd+0x19c
wake_all_kswapds+0x78
__alloc_pages_slowpath+0x1ac
__alloc_pages_noprof+0x298
stack_depot_save_flags+0x6b0
stack_depot_save+0x14
set_track_prepare+0x5c
___slab_alloc+0xccc
__kmalloc_cache_noprof+0x470
__set_page_owner+0x2bc
post_alloc_hook[jt]+0x1b8
prep_new_page+0x28
get_page_from_freelist+0x1edc
__alloc_pages_noprof+0x13c
alloc_slab_page+0x244
allocate_slab+0x7c
___slab_alloc+0x8e8
kmem_cache_alloc_noprof+0x450
debug_objects_fill_pool+0x22c
debug_object_activate+0x40
enqueue_hrtimer[jt]+0xdc
hrtimer_start_range_ns+0x5f8
... |
| In the Linux kernel, the following vulnerability has been resolved:
smb/server: avoid deadlock when linking with ReplaceIfExists
If smb2_create_link() is called with ReplaceIfExists set and the name
does exist then a deadlock will happen.
ksmbd_vfs_kern_path_locked() will return with success and the parent
directory will be locked. ksmbd_vfs_remove_file() will then remove the
file. ksmbd_vfs_link() will then be called while the parent is still
locked. It will try to lock the same parent and will deadlock.
This patch moves the ksmbd_vfs_kern_path_unlock() call to *before*
ksmbd_vfs_link() and then simplifies the code, removing the file_present
flag variable. |
| In the Linux kernel, the following vulnerability has been resolved:
iio: light: opt3001: fix deadlock due to concurrent flag access
The threaded IRQ function in this driver is reading the flag twice: once to
lock a mutex and once to unlock it. Even though the code setting the flag
is designed to prevent it, there are subtle cases where the flag could be
true at the mutex_lock stage and false at the mutex_unlock stage. This
results in the mutex not being unlocked, resulting in a deadlock.
Fix it by making the opt3001_irq() code generally more robust, reading the
flag into a variable and using the variable value at both stages. |
| In the Linux kernel, the following vulnerability has been resolved:
posix-clock: posix-clock: Fix unbalanced locking in pc_clock_settime()
If get_clock_desc() succeeds, it calls fget() for the clockid's fd,
and get the clk->rwsem read lock, so the error path should release
the lock to make the lock balance and fput the clockid's fd to make
the refcount balance and release the fd related resource.
However the below commit left the error path locked behind resulting in
unbalanced locking. Check timespec64_valid_strict() before
get_clock_desc() to fix it, because the "ts" is not changed
after that.
[pabeni@redhat.com: fixed commit message typo] |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: RFCOMM: FIX possible deadlock in rfcomm_sk_state_change
rfcomm_sk_state_change attempts to use sock_lock so it must never be
called with it locked but rfcomm_sock_ioctl always attempt to lock it
causing the following trace:
======================================================
WARNING: possible circular locking dependency detected
6.8.0-syzkaller-08951-gfe46a7dd189e #0 Not tainted
------------------------------------------------------
syz-executor386/5093 is trying to acquire lock:
ffff88807c396258 (sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1671 [inline]
ffff88807c396258 (sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM){+.+.}-{0:0}, at: rfcomm_sk_state_change+0x5b/0x310 net/bluetooth/rfcomm/sock.c:73
but task is already holding lock:
ffff88807badfd28 (&d->lock){+.+.}-{3:3}, at: __rfcomm_dlc_close+0x226/0x6a0 net/bluetooth/rfcomm/core.c:491 |
| In the Linux kernel, the following vulnerability has been resolved:
ext4: fix i_data_sem unlock order in ext4_ind_migrate()
Fuzzing reports a possible deadlock in jbd2_log_wait_commit.
This issue is triggered when an EXT4_IOC_MIGRATE ioctl is set to require
synchronous updates because the file descriptor is opened with O_SYNC.
This can lead to the jbd2_journal_stop() function calling
jbd2_might_wait_for_commit(), potentially causing a deadlock if the
EXT4_IOC_MIGRATE call races with a write(2) system call.
This problem only arises when CONFIG_PROVE_LOCKING is enabled. In this
case, the jbd2_might_wait_for_commit macro locks jbd2_handle in the
jbd2_journal_stop function while i_data_sem is locked. This triggers
lockdep because the jbd2_journal_start function might also lock the same
jbd2_handle simultaneously.
Found by Linux Verification Center (linuxtesting.org) with syzkaller.
Rule: add |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/hns: Fix spin_unlock_irqrestore() called with IRQs enabled
Fix missuse of spin_lock_irq()/spin_unlock_irq() when
spin_lock_irqsave()/spin_lock_irqrestore() was hold.
This was discovered through the lock debugging, and the corresponding
log is as follows:
raw_local_irq_restore() called with IRQs enabled
WARNING: CPU: 96 PID: 2074 at kernel/locking/irqflag-debug.c:10 warn_bogus_irq_restore+0x30/0x40
...
Call trace:
warn_bogus_irq_restore+0x30/0x40
_raw_spin_unlock_irqrestore+0x84/0xc8
add_qp_to_list+0x11c/0x148 [hns_roce_hw_v2]
hns_roce_create_qp_common.constprop.0+0x240/0x780 [hns_roce_hw_v2]
hns_roce_create_qp+0x98/0x160 [hns_roce_hw_v2]
create_qp+0x138/0x258
ib_create_qp_kernel+0x50/0xe8
create_mad_qp+0xa8/0x128
ib_mad_port_open+0x218/0x448
ib_mad_init_device+0x70/0x1f8
add_client_context+0xfc/0x220
enable_device_and_get+0xd0/0x140
ib_register_device.part.0+0xf4/0x1c8
ib_register_device+0x34/0x50
hns_roce_register_device+0x174/0x3d0 [hns_roce_hw_v2]
hns_roce_init+0xfc/0x2c0 [hns_roce_hw_v2]
__hns_roce_hw_v2_init_instance+0x7c/0x1d0 [hns_roce_hw_v2]
hns_roce_hw_v2_init_instance+0x9c/0x180 [hns_roce_hw_v2] |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: cfg80211: restrict NL80211_ATTR_TXQ_QUANTUM values
syzbot is able to trigger softlockups, setting NL80211_ATTR_TXQ_QUANTUM
to 2^31.
We had a similar issue in sch_fq, fixed with commit
d9e15a273306 ("pkt_sched: fq: do not accept silly TCA_FQ_QUANTUM")
watchdog: BUG: soft lockup - CPU#1 stuck for 26s! [kworker/1:0:24]
Modules linked in:
irq event stamp: 131135
hardirqs last enabled at (131134): [<ffff80008ae8778c>] __exit_to_kernel_mode arch/arm64/kernel/entry-common.c:85 [inline]
hardirqs last enabled at (131134): [<ffff80008ae8778c>] exit_to_kernel_mode+0xdc/0x10c arch/arm64/kernel/entry-common.c:95
hardirqs last disabled at (131135): [<ffff80008ae85378>] __el1_irq arch/arm64/kernel/entry-common.c:533 [inline]
hardirqs last disabled at (131135): [<ffff80008ae85378>] el1_interrupt+0x24/0x68 arch/arm64/kernel/entry-common.c:551
softirqs last enabled at (125892): [<ffff80008907e82c>] neigh_hh_init net/core/neighbour.c:1538 [inline]
softirqs last enabled at (125892): [<ffff80008907e82c>] neigh_resolve_output+0x268/0x658 net/core/neighbour.c:1553
softirqs last disabled at (125896): [<ffff80008904166c>] local_bh_disable+0x10/0x34 include/linux/bottom_half.h:19
CPU: 1 PID: 24 Comm: kworker/1:0 Not tainted 6.9.0-rc7-syzkaller-gfda5695d692c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: mld mld_ifc_work
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __list_del include/linux/list.h:195 [inline]
pc : __list_del_entry include/linux/list.h:218 [inline]
pc : list_move_tail include/linux/list.h:310 [inline]
pc : fq_tin_dequeue include/net/fq_impl.h:112 [inline]
pc : ieee80211_tx_dequeue+0x6b8/0x3b4c net/mac80211/tx.c:3854
lr : __list_del_entry include/linux/list.h:218 [inline]
lr : list_move_tail include/linux/list.h:310 [inline]
lr : fq_tin_dequeue include/net/fq_impl.h:112 [inline]
lr : ieee80211_tx_dequeue+0x67c/0x3b4c net/mac80211/tx.c:3854
sp : ffff800093d36700
x29: ffff800093d36a60 x28: ffff800093d36960 x27: dfff800000000000
x26: ffff0000d800ad50 x25: ffff0000d800abe0 x24: ffff0000d800abf0
x23: ffff0000e0032468 x22: ffff0000e00324d4 x21: ffff0000d800abf0
x20: ffff0000d800abf8 x19: ffff0000d800abf0 x18: ffff800093d363c0
x17: 000000000000d476 x16: ffff8000805519dc x15: ffff7000127a6cc8
x14: 1ffff000127a6cc8 x13: 0000000000000004 x12: ffffffffffffffff
x11: ffff7000127a6cc8 x10: 0000000000ff0100 x9 : 0000000000000000
x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000000000
x5 : ffff80009287aa08 x4 : 0000000000000008 x3 : ffff80008034c7fc
x2 : ffff0000e0032468 x1 : 00000000da0e46b8 x0 : ffff0000e0032470
Call trace:
__list_del include/linux/list.h:195 [inline]
__list_del_entry include/linux/list.h:218 [inline]
list_move_tail include/linux/list.h:310 [inline]
fq_tin_dequeue include/net/fq_impl.h:112 [inline]
ieee80211_tx_dequeue+0x6b8/0x3b4c net/mac80211/tx.c:3854
wake_tx_push_queue net/mac80211/util.c:294 [inline]
ieee80211_handle_wake_tx_queue+0x118/0x274 net/mac80211/util.c:315
drv_wake_tx_queue net/mac80211/driver-ops.h:1350 [inline]
schedule_and_wake_txq net/mac80211/driver-ops.h:1357 [inline]
ieee80211_queue_skb+0x18e8/0x2244 net/mac80211/tx.c:1664
ieee80211_tx+0x260/0x400 net/mac80211/tx.c:1966
ieee80211_xmit+0x278/0x354 net/mac80211/tx.c:2062
__ieee80211_subif_start_xmit+0xab8/0x122c net/mac80211/tx.c:4338
ieee80211_subif_start_xmit+0xe0/0x438 net/mac80211/tx.c:4532
__netdev_start_xmit include/linux/netdevice.h:4903 [inline]
netdev_start_xmit include/linux/netdevice.h:4917 [inline]
xmit_one net/core/dev.c:3531 [inline]
dev_hard_start_xmit+0x27c/0x938 net/core/dev.c:3547
__dev_queue_xmit+0x1678/0x33fc net/core/dev.c:4341
dev_queue_xmit include/linux/netdevice.h:3091 [inline]
neigh_resolve_output+0x558/0x658 net/core/neighbour.c:1563
neigh_output include/net/neighbour.h:542 [inline]
ip6_fini
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
pinctrl: fix deadlock in create_pinctrl() when handling -EPROBE_DEFER
In create_pinctrl(), pinctrl_maps_mutex is acquired before calling
add_setting(). If add_setting() returns -EPROBE_DEFER, create_pinctrl()
calls pinctrl_free(). However, pinctrl_free() attempts to acquire
pinctrl_maps_mutex, which is already held by create_pinctrl(), leading to
a potential deadlock.
This patch resolves the issue by releasing pinctrl_maps_mutex before
calling pinctrl_free(), preventing the deadlock.
This bug was discovered and resolved using Coverity Static Analysis
Security Testing (SAST) by Synopsys, Inc. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: Fix deadlock in ieee80211_sta_ps_deliver_wakeup()
The ieee80211_sta_ps_deliver_wakeup() function takes sta->ps_lock to
synchronizes with ieee80211_tx_h_unicast_ps_buf() which is called from
softirq context. However using only spin_lock() to get sta->ps_lock in
ieee80211_sta_ps_deliver_wakeup() does not prevent softirq to execute
on this same CPU, to run ieee80211_tx_h_unicast_ps_buf() and try to
take this same lock ending in deadlock. Below is an example of rcu stall
that arises in such situation.
rcu: INFO: rcu_sched self-detected stall on CPU
rcu: 2-....: (42413413 ticks this GP) idle=b154/1/0x4000000000000000 softirq=1763/1765 fqs=21206996
rcu: (t=42586894 jiffies g=2057 q=362405 ncpus=4)
CPU: 2 PID: 719 Comm: wpa_supplicant Tainted: G W 6.4.0-02158-g1b062f552873 #742
Hardware name: RPT (r1) (DT)
pstate: 00000005 (nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : queued_spin_lock_slowpath+0x58/0x2d0
lr : invoke_tx_handlers_early+0x5b4/0x5c0
sp : ffff00001ef64660
x29: ffff00001ef64660 x28: ffff000009bc1070 x27: ffff000009bc0ad8
x26: ffff000009bc0900 x25: ffff00001ef647a8 x24: 0000000000000000
x23: ffff000009bc0900 x22: ffff000009bc0900 x21: ffff00000ac0e000
x20: ffff00000a279e00 x19: ffff00001ef646e8 x18: 0000000000000000
x17: ffff800016468000 x16: ffff00001ef608c0 x15: 0010533c93f64f80
x14: 0010395c9faa3946 x13: 0000000000000000 x12: 00000000fa83b2da
x11: 000000012edeceea x10: ffff0000010fbe00 x9 : 0000000000895440
x8 : 000000000010533c x7 : ffff00000ad8b740 x6 : ffff00000c350880
x5 : 0000000000000007 x4 : 0000000000000001 x3 : 0000000000000000
x2 : 0000000000000000 x1 : 0000000000000001 x0 : ffff00000ac0e0e8
Call trace:
queued_spin_lock_slowpath+0x58/0x2d0
ieee80211_tx+0x80/0x12c
ieee80211_tx_pending+0x110/0x278
tasklet_action_common.constprop.0+0x10c/0x144
tasklet_action+0x20/0x28
_stext+0x11c/0x284
____do_softirq+0xc/0x14
call_on_irq_stack+0x24/0x34
do_softirq_own_stack+0x18/0x20
do_softirq+0x74/0x7c
__local_bh_enable_ip+0xa0/0xa4
_ieee80211_wake_txqs+0x3b0/0x4b8
__ieee80211_wake_queue+0x12c/0x168
ieee80211_add_pending_skbs+0xec/0x138
ieee80211_sta_ps_deliver_wakeup+0x2a4/0x480
ieee80211_mps_sta_status_update.part.0+0xd8/0x11c
ieee80211_mps_sta_status_update+0x18/0x24
sta_apply_parameters+0x3bc/0x4c0
ieee80211_change_station+0x1b8/0x2dc
nl80211_set_station+0x444/0x49c
genl_family_rcv_msg_doit.isra.0+0xa4/0xfc
genl_rcv_msg+0x1b0/0x244
netlink_rcv_skb+0x38/0x10c
genl_rcv+0x34/0x48
netlink_unicast+0x254/0x2bc
netlink_sendmsg+0x190/0x3b4
____sys_sendmsg+0x1e8/0x218
___sys_sendmsg+0x68/0x8c
__sys_sendmsg+0x44/0x84
__arm64_sys_sendmsg+0x20/0x28
do_el0_svc+0x6c/0xe8
el0_svc+0x14/0x48
el0t_64_sync_handler+0xb0/0xb4
el0t_64_sync+0x14c/0x150
Using spin_lock_bh()/spin_unlock_bh() instead prevents softirq to raise
on the same CPU that is holding the lock. |
