[syzbot] [bpf?] [net?] possible deadlock in try_to_wake_up (4)

From: syzbot
Date: Mon Mar 18 2024 - 12:03:11 EST

Hello,

syzbot found the following issue on:

HEAD commit: 0740b6427e90 Merge branch 'bpf-arena-followups'
git tree: bpf
console output: https://syzkaller.appspot.com/x/log.txt?x=14785c6e180000
kernel config: https://syzkaller.appspot.com/x/.config?x=6fb1be60a193d440
dashboard link: https://syzkaller.appspot.com/bug?extid=21f93e66c95001d6f61a
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1240e879180000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12c9c546180000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/c9e6e9f97566/disk-0740b642.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/78476a588b62/vmlinux-0740b642.xz
kernel image: https://storage.googleapis.com/syzbot-assets/50cd6fab9ead/bzImage-0740b642.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+21f93e66c95001d6f61a@xxxxxxxxxxxxxxxxxxxxxxxxx

=====================================================
WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected
6.8.0-syzkaller-05226-g0740b6427e90 #0 Not tainted
-----------------------------------------------------
kworker/u8:1/11 [HC0[0]:SC0[2]:HE0:SE0] is trying to acquire:
ffff888021ba0578 (&htab->buckets[i].lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
ffff888021ba0578 (&htab->buckets[i].lock){+...}-{2:2}, at: sock_hash_delete_elem+0xb0/0x300 net/core/sock_map.c:939

and this task is already holding:
ffff888017ba2810 (&p->pi_lock){-.-.}-{2:2}, at: class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:553 [inline]
ffff888017ba2810 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0xb0/0x1470 kernel/sched/core.c:4262
which would create a new lock dependency:
(&p->pi_lock){-.-.}-{2:2} -> (&htab->buckets[i].lock){+...}-{2:2}

but this new dependency connects a HARDIRQ-irq-safe lock:
(&p->pi_lock){-.-.}-{2:2}

.. which became HARDIRQ-irq-safe at:
lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:553 [inline]
try_to_wake_up+0xb0/0x1470 kernel/sched/core.c:4262
autoremove_wake_function+0x16/0x110 kernel/sched/wait.c:384
__wake_up_common kernel/sched/wait.c:89 [inline]
__wake_up_common_lock+0x130/0x1e0 kernel/sched/wait.c:106
irq_work_single+0xe2/0x240 kernel/irq_work.c:221
irq_work_run_list kernel/irq_work.c:252 [inline]
irq_work_run+0x18b/0x350 kernel/irq_work.c:261
__sysvec_irq_work+0xa8/0x3e0 arch/x86/kernel/irq_work.c:22
instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline]
sysvec_irq_work+0x9e/0xc0 arch/x86/kernel/irq_work.c:17
asm_sysvec_irq_work+0x1a/0x20 arch/x86/include/asm/idtentry.h:738
__wrmsr arch/x86/include/asm/msr.h:96 [inline]
native_write_msr arch/x86/include/asm/msr.h:160 [inline]
wrmsr arch/x86/include/asm/msr.h:269 [inline]
native_apic_msr_write+0x39/0x50 arch/x86/include/asm/apic.h:207
__apic_send_IPI_self arch/x86/include/asm/apic.h:458 [inline]
arch_irq_work_raise+0x6f/0x80 arch/x86/kernel/irq_work.c:31
irq_work_queue+0xa7/0x150 kernel/irq_work.c:124
__kfence_alloc+0x22e/0x370 mm/kfence/core.c:1088
kfence_alloc include/linux/kfence.h:129 [inline]
slab_alloc_node mm/slub.c:3846 [inline]
__do_kmalloc_node mm/slub.c:3980 [inline]
__kmalloc+0x41c/0x4a0 mm/slub.c:3994
kmalloc include/linux/slab.h:594 [inline]
kzalloc include/linux/slab.h:711 [inline]
alloc_workqueue+0x1b0/0x20c0 kernel/workqueue.c:5542
init_mm_internals+0x17/0x120 mm/vmstat.c:2122
kernel_init_freeable+0x403/0x5d0 init/main.c:1543
kernel_init+0x1d/0x2a0 init/main.c:1446
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243

to a HARDIRQ-irq-unsafe lock:
(&htab->buckets[i].lock){+...}-{2:2}

.. which became HARDIRQ-irq-unsafe at:
..
lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
_raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178
spin_lock_bh include/linux/spinlock.h:356 [inline]
sock_hash_free+0x164/0x820 net/core/sock_map.c:1154
bpf_map_free_deferred+0xe6/0x110 kernel/bpf/syscall.c:734
process_one_work kernel/workqueue.c:3254 [inline]
process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
kthread+0x2f0/0x390 kernel/kthread.c:388
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243

other info that might help us debug this:

Possible interrupt unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&htab->buckets[i].lock);
local_irq_disable();
lock(&p->pi_lock);
lock(&htab->buckets[i].lock);
<Interrupt>
lock(&p->pi_lock);

*** DEADLOCK ***

4 locks held by kworker/u8:1/11:
#0: ffff888014c81148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3229 [inline]
#0: ffff888014c81148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x1770 kernel/workqueue.c:3335
#1: ffffc90000107d00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline]
#1: ffffc90000107d00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x1770 kernel/workqueue.c:3335
#2: ffff888017ba2810 (&p->pi_lock){-.-.}-{2:2}, at: class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:553 [inline]
#2: ffff888017ba2810 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0xb0/0x1470 kernel/sched/core.c:4262
#3: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
#3: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline]
#3: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2380 [inline]
#3: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x114/0x420 kernel/trace/bpf_trace.c:2420

the dependencies between HARDIRQ-irq-safe lock and the holding lock:
-> (&p->pi_lock){-.-.}-{2:2} {
IN-HARDIRQ-W at:
lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:553 [inline]
try_to_wake_up+0xb0/0x1470 kernel/sched/core.c:4262
autoremove_wake_function+0x16/0x110 kernel/sched/wait.c:384
__wake_up_common kernel/sched/wait.c:89 [inline]
__wake_up_common_lock+0x130/0x1e0 kernel/sched/wait.c:106
irq_work_single+0xe2/0x240 kernel/irq_work.c:221
irq_work_run_list kernel/irq_work.c:252 [inline]
irq_work_run+0x18b/0x350 kernel/irq_work.c:261
__sysvec_irq_work+0xa8/0x3e0 arch/x86/kernel/irq_work.c:22
instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline]
sysvec_irq_work+0x9e/0xc0 arch/x86/kernel/irq_work.c:17
asm_sysvec_irq_work+0x1a/0x20 arch/x86/include/asm/idtentry.h:738
__wrmsr arch/x86/include/asm/msr.h:96 [inline]
native_write_msr arch/x86/include/asm/msr.h:160 [inline]
wrmsr arch/x86/include/asm/msr.h:269 [inline]
native_apic_msr_write+0x39/0x50 arch/x86/include/asm/apic.h:207
__apic_send_IPI_self arch/x86/include/asm/apic.h:458 [inline]
arch_irq_work_raise+0x6f/0x80 arch/x86/kernel/irq_work.c:31
irq_work_queue+0xa7/0x150 kernel/irq_work.c:124
__kfence_alloc+0x22e/0x370 mm/kfence/core.c:1088
kfence_alloc include/linux/kfence.h:129 [inline]
slab_alloc_node mm/slub.c:3846 [inline]
__do_kmalloc_node mm/slub.c:3980 [inline]
__kmalloc+0x41c/0x4a0 mm/slub.c:3994
kmalloc include/linux/slab.h:594 [inline]
kzalloc include/linux/slab.h:711 [inline]
alloc_workqueue+0x1b0/0x20c0 kernel/workqueue.c:5542
init_mm_internals+0x17/0x120 mm/vmstat.c:2122
kernel_init_freeable+0x403/0x5d0 init/main.c:1543
kernel_init+0x1d/0x2a0 init/main.c:1446
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
IN-SOFTIRQ-W at:
lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:553 [inline]
try_to_wake_up+0xb0/0x1470 kernel/sched/core.c:4262
call_timer_fn+0x17e/0x600 kernel/time/timer.c:1792
expire_timers kernel/time/timer.c:1843 [inline]
__run_timers kernel/time/timer.c:2408 [inline]
__run_timer_base+0x66a/0x8e0 kernel/time/timer.c:2419
run_timer_base kernel/time/timer.c:2428 [inline]
run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2438
__do_softirq+0x2bc/0x943 kernel/softirq.c:554
invoke_softirq kernel/softirq.c:428 [inline]
__irq_exit_rcu+0xf2/0x1c0 kernel/softirq.c:633
irq_exit_rcu+0x9/0x30 kernel/softirq.c:645
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
arch_safe_halt arch/x86/include/asm/irqflags.h:86 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:742
default_idle_call+0x74/0xb0 kernel/sched/idle.c:117
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x22f/0x5d0 kernel/sched/idle.c:332
cpu_startup_entry+0x42/0x60 kernel/sched/idle.c:430
rest_init+0x2e0/0x300 init/main.c:730
arch_call_rest_init+0xe/0x10 init/main.c:831
start_kernel+0x47a/0x500 init/main.c:1077
x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:509
x86_64_start_kernel+0x99/0xa0 arch/x86/kernel/head64.c:490
common_startup_64+0x13e/0x147
INITIAL USE at:
lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
sched_cgroup_fork+0x33/0x410 kernel/sched/core.c:4828
copy_process+0x2217/0x3df0 kernel/fork.c:2498
kernel_clone+0x21e/0x8d0 kernel/fork.c:2796
user_mode_thread+0x132/0x1a0 kernel/fork.c:2874
rest_init+0x27/0x300 init/main.c:695
arch_call_rest_init+0xe/0x10 init/main.c:831
start_kernel+0x47a/0x500 init/main.c:1077
x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:509
x86_64_start_kernel+0x99/0xa0 arch/x86/kernel/head64.c:490
common_startup_64+0x13e/0x147
}
... key at: [<ffffffff926bf780>] rt_mutex_init_task.__key+0x0/0x20

the dependencies between the lock to be acquired
and HARDIRQ-irq-unsafe lock:
-> (&htab->buckets[i].lock){+...}-{2:2} {
HARDIRQ-ON-W at:
lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
_raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178
spin_lock_bh include/linux/spinlock.h:356 [inline]
sock_hash_free+0x164/0x820 net/core/sock_map.c:1154
bpf_map_free_deferred+0xe6/0x110 kernel/bpf/syscall.c:734
process_one_work kernel/workqueue.c:3254 [inline]
process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
kthread+0x2f0/0x390 kernel/kthread.c:388
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
INITIAL USE at:
lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
_raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178
spin_lock_bh include/linux/spinlock.h:356 [inline]
sock_hash_free+0x164/0x820 net/core/sock_map.c:1154
bpf_map_free_deferred+0xe6/0x110 kernel/bpf/syscall.c:734
process_one_work kernel/workqueue.c:3254 [inline]
process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
kthread+0x2f0/0x390 kernel/kthread.c:388
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
}
... key at: [<ffffffff94882300>] sock_hash_alloc.__key+0x0/0x20
... acquired at:
lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
_raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178
spin_lock_bh include/linux/spinlock.h:356 [inline]
sock_hash_delete_elem+0xb0/0x300 net/core/sock_map.c:939
bpf_prog_2c29ac5cdc6b1842+0x42/0x46
bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline]
__bpf_prog_run include/linux/filter.h:657 [inline]
bpf_prog_run include/linux/filter.h:664 [inline]
__bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline]
bpf_trace_run2+0x204/0x420 kernel/trace/bpf_trace.c:2420
trace_sched_migrate_task include/trace/events/sched.h:274 [inline]
set_task_cpu+0x53d/0x5b0 kernel/sched/core.c:3390
try_to_wake_up+0x75b/0x1470 kernel/sched/core.c:4372
wake_up_process kernel/sched/core.c:4510 [inline]
wake_up_q+0xc8/0x120 kernel/sched/core.c:1029
__mutex_unlock_slowpath+0x6f9/0x750 kernel/locking/mutex.c:956
synchronize_rcu_expedited+0x697/0x820 kernel/rcu/tree_exp.h:959
synchronize_rcu+0x136/0x3e0 kernel/rcu/tree.c:3611
sock_hash_free+0xac/0x820 net/core/sock_map.c:1144
bpf_map_free_deferred+0xe6/0x110 kernel/bpf/syscall.c:734
process_one_work kernel/workqueue.c:3254 [inline]
process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
kthread+0x2f0/0x390 kernel/kthread.c:388
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243


stack backtrace:
CPU: 1 PID: 11 Comm: kworker/u8:1 Not tainted 6.8.0-syzkaller-05226-g0740b6427e90 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
Workqueue: events_unbound bpf_map_free_deferred
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106
print_bad_irq_dependency kernel/locking/lockdep.c:2626 [inline]
check_irq_usage kernel/locking/lockdep.c:2865 [inline]
check_prev_add kernel/locking/lockdep.c:3138 [inline]
check_prevs_add kernel/locking/lockdep.c:3253 [inline]
validate_chain+0x4dc7/0x58e0 kernel/locking/lockdep.c:3869
__lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
_raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178
spin_lock_bh include/linux/spinlock.h:356 [inline]
sock_hash_delete_elem+0xb0/0x300 net/core/sock_map.c:939
bpf_prog_2c29ac5cdc6b1842+0x42/0x46
bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline]
__bpf_prog_run include/linux/filter.h:657 [inline]
bpf_prog_run include/linux/filter.h:664 [inline]
__bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline]
bpf_trace_run2+0x204/0x420 kernel/trace/bpf_trace.c:2420
trace_sched_migrate_task include/trace/events/sched.h:274 [inline]
set_task_cpu+0x53d/0x5b0 kernel/sched/core.c:3390
try_to_wake_up+0x75b/0x1470 kernel/sched/core.c:4372
wake_up_process kernel/sched/core.c:4510 [inline]
wake_up_q+0xc8/0x120 kernel/sched/core.c:1029
__mutex_unlock_slowpath+0x6f9/0x750 kernel/locking/mutex.c:956
synchronize_rcu_expedited+0x697/0x820 kernel/rcu/tree_exp.h:959
synchronize_rcu+0x136/0x3e0 kernel/rcu/tree.c:3611
sock_hash_free+0xac/0x820 net/core/sock_map.c:1144
bpf_map_free_deferred+0xe6/0x110 kernel/bpf/syscall.c:734
process_one_work kernel/workqueue.c:3254 [inline]
process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
kthread+0x2f0/0x390 kernel/kthread.c:388
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
</TASK>
------------[ cut here ]------------
raw_local_irq_restore() called with IRQs enabled
WARNING: CPU: 1 PID: 11 at kernel/locking/irqflag-debug.c:10 warn_bogus_irq_restore+0x29/0x40 kernel/locking/irqflag-debug.c:10
Modules linked in:
CPU: 1 PID: 11 Comm: kworker/u8:1 Not tainted 6.8.0-syzkaller-05226-g0740b6427e90 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
Workqueue: events_unbound bpf_map_free_deferred
RIP: 0010:warn_bogus_irq_restore+0x29/0x40 kernel/locking/irqflag-debug.c:10
Code: 90 f3 0f 1e fa 90 80 3d 9e 69 01 04 00 74 06 90 c3 cc cc cc cc c6 05 8f 69 01 04 01 90 48 c7 c7 20 ba aa 8b e8 f8 e5 e7 f5 90 <0f> 0b 90 90 90 c3 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 0f 1f
RSP: 0018:ffffc90000107338 EFLAGS: 00010246
RAX: 5cdc287fd92d5000 RBX: 1ffff92000020e6c RCX: ffff8880172abc00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900001073d0 R08: ffffffff8157cc12 R09: 1ffffffff1f0d5c5
R10: dffffc0000000000 R11: fffffbfff1f0d5c6 R12: dffffc0000000000
R13: 1ffff92000020e68 R14: ffffc90000107360 R15: 0000000000000246
FS: 0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555942e1ca8 CR3: 0000000066096000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline]
_raw_spin_unlock_irqrestore+0x120/0x140 kernel/locking/spinlock.c:194
class_raw_spinlock_irqsave_destructor include/linux/spinlock.h:553 [inline]
try_to_wake_up+0x902/0x1470 kernel/sched/core.c:4262
wake_up_process kernel/sched/core.c:4510 [inline]
wake_up_q+0xc8/0x120 kernel/sched/core.c:1029
__mutex_unlock_slowpath+0x6f9/0x750 kernel/locking/mutex.c:956
synchronize_rcu_expedited+0x697/0x820 kernel/rcu/tree_exp.h:959
synchronize_rcu+0x136/0x3e0 kernel/rcu/tree.c:3611
sock_hash_free+0xac/0x820 net/core/sock_map.c:1144
bpf_map_free_deferred+0xe6/0x110 kernel/bpf/syscall.c:734
process_one_work kernel/workqueue.c:3254 [inline]
process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
kthread+0x2f0/0x390 kernel/kthread.c:388
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
</TASK>


---
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