[v6.6] possible deadlock in padata_do_serial

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: eac8889a3a1c Linux 6.6.140
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=14ca302e580000
kernel config: https://syzkaller.appspot.com/x/.config?x=c5b35c4db8465904
dashboard link: https://syzkaller.appspot.com/bug?extid=e3d4090c4aca807a9ac5
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/284081ee4b1a/disk-eac8889a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/6503c72409ee/vmlinux-eac8889a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/5e529dbebdcb/bzImage-eac8889a.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e3d409...@syzkaller.appspotmail.com

============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
kworker/u4:10/2996 is trying to acquire lock:
ffffe8ffffd53678 (&pd_list->lock){+...}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffffe8ffffd53678 (&pd_list->lock){+...}-{2:2}, at: padata_find_next kernel/padata.c:272 [inline]
ffffe8ffffd53678 (&pd_list->lock){+...}-{2:2}, at: padata_reorder kernel/padata.c:325 [inline]
ffffe8ffffd53678 (&pd_list->lock){+...}-{2:2}, at: padata_do_serial+0x644/0xa70 kernel/padata.c:395

but task is already holding lock:
ffffe8ffffd54620 (&pd_list->lock){+...}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffffe8ffffd54620 (&pd_list->lock){+...}-{2:2}, at: padata_reorder kernel/padata.c:316 [inline]
ffffe8ffffd54620 (&pd_list->lock){+...}-{2:2}, at: padata_do_serial+0x4db/0xa70 kernel/padata.c:395

other info that might help us debug this:
Possible unsafe locking scenario:

CPU0
----
lock(&pd_list->lock);
lock(&pd_list->lock);

*** DEADLOCK ***

May be due to missing lock nesting notation

3 locks held by kworker/u4:10/2996:
#0: ffff88814567d138 ((wq_completion)pencrypt_parallel){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#0: ffff88814567d138 ((wq_completion)pencrypt_parallel){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
#1: ffffc9000bf57d00 ((work_completion)(&pw->pw_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#1: ffffc9000bf57d00 ((work_completion)(&pw->pw_work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
#2: ffffe8ffffd54620 (&pd_list->lock){+...}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
#2: ffffe8ffffd54620 (&pd_list->lock){+...}-{2:2}, at: padata_reorder kernel/padata.c:316 [inline]
#2: ffffe8ffffd54620 (&pd_list->lock){+...}-{2:2}, at: padata_do_serial+0x4db/0xa70 kernel/padata.c:395

stack backtrace:
CPU: 1 PID: 2996 Comm: kworker/u4:10 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: pencrypt_parallel padata_parallel_worker
Call Trace:
<TASK>
dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
check_deadlock kernel/locking/lockdep.c:3062 [inline]
validate_chain kernel/locking/lockdep.c:3856 [inline]
__lock_acquire+0x5dbc/0x7d40 kernel/locking/lockdep.c:5137
lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
padata_find_next kernel/padata.c:272 [inline]
padata_reorder kernel/padata.c:325 [inline]
padata_do_serial+0x644/0xa70 kernel/padata.c:395
padata_parallel_worker+0x6f/0x1c0 kernel/padata.c:168
process_one_work kernel/workqueue.c:2653 [inline]
process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 0a40c6fbd105 Linux 6.6.141
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=152a8a2e580000

kernel config: https://syzkaller.appspot.com/x/.config?x=c5b35c4db8465904
dashboard link: https://syzkaller.appspot.com/bug?extid=e3d4090c4aca807a9ac5
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13e636d2580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=142bfe2e580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/bef5f7e53495/disk-0a40c6fb.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/61ce39aaab25/vmlinux-0a40c6fb.xz
kernel image: https://storage.googleapis.com/syzbot-assets/43d2363e7871/bzImage-0a40c6fb.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e3d409...@syzkaller.appspotmail.com

wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50

============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------

kworker/u4:7/1085 is trying to acquire lock:
ffffe8ffffd265b0 (&pd_list->lock){+...}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffffe8ffffd265b0 (&pd_list->lock){+...}-{2:2}, at: padata_find_next kernel/padata.c:272 [inline]
ffffe8ffffd265b0 (&pd_list->lock){+...}-{2:2}, at: padata_reorder kernel/padata.c:325 [inline]
ffffe8ffffd265b0 (&pd_list->lock){+...}-{2:2}, at: padata_do_serial+0x644/0xa70 kernel/padata.c:395

but task is already holding lock:

ffffe8ffffc266a8 (&pd_list->lock){+...}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffffe8ffffc266a8 (&pd_list->lock){+...}-{2:2}, at: padata_reorder kernel/padata.c:316 [inline]
ffffe8ffffc266a8 (&pd_list->lock){+...}-{2:2}, at: padata_do_serial+0x4db/0xa70 kernel/padata.c:395

other info that might help us debug this:
Possible unsafe locking scenario:

CPU0
----
lock(&pd_list->lock);
lock(&pd_list->lock);

*** DEADLOCK ***

May be due to missing lock nesting notation

3 locks held by kworker/u4:7/1085:
#0: ffff88814005cd38 ((wq_completion)pencrypt_parallel){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#0: ffff88814005cd38 ((wq_completion)pencrypt_parallel){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
#1: ffffc900049afd00 ((work_completion)(&pw->pw_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
#1: ffffc900049afd00 ((work_completion)(&pw->pw_work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
#2: ffffe8ffffc266a8 (&pd_list->lock){+...}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
#2: ffffe8ffffc266a8 (&pd_list->lock){+...}-{2:2}, at: padata_reorder kernel/padata.c:316 [inline]
#2: ffffe8ffffc266a8 (&pd_list->lock){+...}-{2:2}, at: padata_do_serial+0x4db/0xa70 kernel/padata.c:395

stack backtrace:
CPU: 0 PID: 1085 Comm: kworker/u4:7 Not tainted syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: pencrypt_parallel padata_parallel_worker
Call Trace:
<TASK>
dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
check_deadlock kernel/locking/lockdep.c:3062 [inline]
validate_chain kernel/locking/lockdep.c:3856 [inline]
__lock_acquire+0x5dbc/0x7d40 kernel/locking/lockdep.c:5137
lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
padata_find_next kernel/padata.c:272 [inline]
padata_reorder kernel/padata.c:325 [inline]
padata_do_serial+0x644/0xa70 kernel/padata.c:395
padata_parallel_worker+0x6f/0x1c0 kernel/padata.c:168
process_one_work kernel/workqueue.c:2653 [inline]
process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>


---

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: dc027a595035 Linux 5.15.209
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=17c735ec580000
kernel config: https://syzkaller.appspot.com/x/.config?x=353ae28c40b35af5
dashboard link: https://syzkaller.appspot.com/bug?extid=e7e2691a01e9b749f1e5

compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/586ac2a2fd9d/disk-dc027a59.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/06dcb6a2fcd3/vmlinux-dc027a59.xz
kernel image: https://storage.googleapis.com/syzbot-assets/567131e0cbcc/bzImage-dc027a59.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:

Reported-by: syzbot+e7e269...@syzkaller.appspotmail.com

============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------

kworker/u4:7/4401 is trying to acquire lock:
ffffe8ffffdfaf88 (&pd_list->lock){+...}-{2:2}, at: spin_lock include/linux/spinlock.h:364 [inline]
ffffe8ffffdfaf88 (&pd_list->lock){+...}-{2:2}, at: padata_find_next kernel/padata.c:264 [inline]
ffffe8ffffdfaf88 (&pd_list->lock){+...}-{2:2}, at: padata_reorder kernel/padata.c:317 [inline]
ffffe8ffffdfaf88 (&pd_list->lock){+...}-{2:2}, at: padata_do_serial+0x585/0x9a0 kernel/padata.c:387

but task is already holding lock:

ffffe8ffffcff028 (&pd_list->lock){+...}-{2:2}, at: spin_lock include/linux/spinlock.h:364 [inline]
ffffe8ffffcff028 (&pd_list->lock){+...}-{2:2}, at: padata_reorder kernel/padata.c:308 [inline]
ffffe8ffffcff028 (&pd_list->lock){+...}-{2:2}, at: padata_do_serial+0x41c/0x9a0 kernel/padata.c:387

other info that might help us debug this:
Possible unsafe locking scenario:

CPU0
----
lock(&pd_list->lock);
lock(&pd_list->lock);

*** DEADLOCK ***

May be due to missing lock nesting notation

3 locks held by kworker/u4:7/4401:
#0: ffff888016e44938 ((wq_completion)pencrypt_parallel){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
#1: ffffc9000331fd00 ((work_completion)(&pw->pw_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
#2: ffffe8ffffcff028 (&pd_list->lock){+...}-{2:2}, at: spin_lock include/linux/spinlock.h:364 [inline]
#2: ffffe8ffffcff028 (&pd_list->lock){+...}-{2:2}, at: padata_reorder kernel/padata.c:308 [inline]
#2: ffffe8ffffcff028 (&pd_list->lock){+...}-{2:2}, at: padata_do_serial+0x41c/0x9a0 kernel/padata.c:387

stack backtrace:
CPU: 1 PID: 4401 Comm: kworker/u4:7 Not tainted syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: pencrypt_parallel padata_parallel_worker
Call Trace:
<TASK>

dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
__lock_acquire+0x1236/0x7d10 kernel/locking/lockdep.c:-1
lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
__raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:364 [inline]
padata_find_next kernel/padata.c:264 [inline]
padata_reorder kernel/padata.c:317 [inline]
padata_do_serial+0x585/0x9a0 kernel/padata.c:387
padata_parallel_worker+0x5c/0x1a0 kernel/padata.c:160
process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 228da13e907e Linux 6.1.175
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1729acee580000
kernel config: https://syzkaller.appspot.com/x/.config?x=4dd3c1715f0a309b
dashboard link: https://syzkaller.appspot.com/bug?extid=2c131d5163e78241b68b

compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:

disk image: https://storage.googleapis.com/syzbot-assets/a1730af56ab4/disk-228da13e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/eafe9b37a422/vmlinux-228da13e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7353ac7f337a/bzImage-228da13e.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:

Reported-by: syzbot+2c131d...@syzkaller.appspotmail.com

============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------

kworker/u4:32/9069 is trying to acquire lock:
ffffe8ffffd770a8 (&pd_list->lock){+...}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffffe8ffffd770a8 (&pd_list->lock){+...}-{2:2}, at: padata_find_next kernel/padata.c:264 [inline]
ffffe8ffffd770a8 (&pd_list->lock){+...}-{2:2}, at: padata_reorder kernel/padata.c:317 [inline]
ffffe8ffffd770a8 (&pd_list->lock){+...}-{2:2}, at: padata_do_serial+0x62b/0xaa0 kernel/padata.c:387

but task is already holding lock:

ffffe8ffffda4540 (&pd_list->lock){+...}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffffe8ffffda4540 (&pd_list->lock){+...}-{2:2}, at: padata_reorder kernel/padata.c:308 [inline]
ffffe8ffffda4540 (&pd_list->lock){+...}-{2:2}, at: padata_do_serial+0x4c2/0xaa0 kernel/padata.c:387

other info that might help us debug this:
Possible unsafe locking scenario:

CPU0
----
lock(&pd_list->lock);
lock(&pd_list->lock);

*** DEADLOCK ***

May be due to missing lock nesting notation

3 locks held by kworker/u4:32/9069:
#0: ffff8880176ae138 ((wq_completion)pencrypt_parallel){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc900037a7d00 ((work_completion)(&pw->pw_work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#2: ffffe8ffffda4540 (&pd_list->lock){+...}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
#2: ffffe8ffffda4540 (&pd_list->lock){+...}-{2:2}, at: padata_reorder kernel/padata.c:308 [inline]
#2: ffffe8ffffda4540 (&pd_list->lock){+...}-{2:2}, at: padata_do_serial+0x4c2/0xaa0 kernel/padata.c:387

stack backtrace:
CPU: 0 PID: 9069 Comm: kworker/u4:32 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026

Workqueue: pencrypt_parallel padata_parallel_worker
Call Trace:
<TASK>

dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
__lock_acquire+0x123e/0x7d10 kernel/locking/lockdep.c:-1
lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]

padata_find_next kernel/padata.c:264 [inline]
padata_reorder kernel/padata.c:317 [inline]

padata_do_serial+0x62b/0xaa0 kernel/padata.c:387
padata_parallel_worker+0x6b/0x1c0 kernel/padata.c:160
process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: dc027a595035 Linux 5.15.209
git tree: linux-5.15.y

console output: https://syzkaller.appspot.com/x/log.txt?x=17e7b32e580000

kernel config: https://syzkaller.appspot.com/x/.config?x=353ae28c40b35af5
dashboard link: https://syzkaller.appspot.com/bug?extid=e7e2691a01e9b749f1e5
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=106b512e580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13dc5b5e580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/586ac2a2fd9d/disk-dc027a59.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/06dcb6a2fcd3/vmlinux-dc027a59.xz
kernel image: https://storage.googleapis.com/syzbot-assets/567131e0cbcc/bzImage-dc027a59.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e7e269...@syzkaller.appspotmail.com

============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------

kworker/u4:2/145 is trying to acquire lock:
ffffe8ffffd37ab8 (&pd_list->lock){+...}-{2:2}, at: spin_lock include/linux/spinlock.h:364 [inline]
ffffe8ffffd37ab8 (&pd_list->lock){+...}-{2:2}, at: padata_find_next kernel/padata.c:264 [inline]
ffffe8ffffd37ab8 (&pd_list->lock){+...}-{2:2}, at: padata_reorder kernel/padata.c:317 [inline]
ffffe8ffffd37ab8 (&pd_list->lock){+...}-{2:2}, at: padata_do_serial+0x585/0x9a0 kernel/padata.c:387

but task is already holding lock:

ffffe8ffffd37b08 (&pd_list->lock){+...}-{2:2}, at: spin_lock include/linux/spinlock.h:364 [inline]
ffffe8ffffd37b08 (&pd_list->lock){+...}-{2:2}, at: padata_reorder kernel/padata.c:308 [inline]
ffffe8ffffd37b08 (&pd_list->lock){+...}-{2:2}, at: padata_do_serial+0x41c/0x9a0 kernel/padata.c:387

other info that might help us debug this:
Possible unsafe locking scenario:

CPU0
----
lock(&pd_list->lock);
lock(&pd_list->lock);

*** DEADLOCK ***

May be due to missing lock nesting notation

3 locks held by kworker/u4:2/145:
#0: ffff8881445ac938 ((wq_completion)pencrypt_parallel){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
#1: ffffc9000169fd00 ((work_completion)(&pw->pw_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
#2: ffffe8ffffd37b08 (&pd_list->lock){+...}-{2:2}, at: spin_lock include/linux/spinlock.h:364 [inline]
#2: ffffe8ffffd37b08 (&pd_list->lock){+...}-{2:2}, at: padata_reorder kernel/padata.c:308 [inline]
#2: ffffe8ffffd37b08 (&pd_list->lock){+...}-{2:2}, at: padata_do_serial+0x41c/0x9a0 kernel/padata.c:387

stack backtrace:
CPU: 1 PID: 145 Comm: kworker/u4:2 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026

Workqueue: pencrypt_parallel padata_parallel_worker
Call Trace:
<TASK>
dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
__lock_acquire+0x1236/0x7d10 kernel/locking/lockdep.c:-1
lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
__raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:364 [inline]
padata_find_next kernel/padata.c:264 [inline]
padata_reorder kernel/padata.c:317 [inline]
padata_do_serial+0x585/0x9a0 kernel/padata.c:387
padata_parallel_worker+0x5c/0x1a0 kernel/padata.c:160
process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
</TASK>


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