syzbot


possible deadlock in __run_timer_base (2)

Status: upstream: reported on 2025/02/09 20:43
Subsystems: cgroups
[Documentation on labels]
Reported-by: syzbot+ed801a886dfdbfe7136d@syzkaller.appspotmail.com
First crash: 50d, last: 33d
Discussions (11)
Title Replies (including bot) Last reply
[PATCH AUTOSEL 5.4] locking/semaphore: Use wake_q to wake up processes outside lock critical section 1 (1) 2025/03/17 16:40
[PATCH AUTOSEL 5.10 1/2] locking/semaphore: Use wake_q to wake up processes outside lock critical section 1 (1) 2025/03/17 16:40
[PATCH AUTOSEL 5.15 1/4] locking/semaphore: Use wake_q to wake up processes outside lock critical section 1 (1) 2025/03/17 16:39
[PATCH AUTOSEL 6.1 1/4] locking/semaphore: Use wake_q to wake up processes outside lock critical section 1 (1) 2025/03/17 16:39
[PATCH AUTOSEL 6.6 3/8] locking/semaphore: Use wake_q to wake up processes outside lock critical section 1 (1) 2025/03/17 16:38
[PATCH AUTOSEL 6.12 06/13] locking/semaphore: Use wake_q to wake up processes outside lock critical section 1 (1) 2025/03/17 16:38
[PATCH AUTOSEL 6.13 07/16] locking/semaphore: Use wake_q to wake up processes outside lock critical section 1 (1) 2025/03/17 16:37
[PATCH locking 02/11] locking/semaphore: Use wake_q to wake up processes outside lock critical section 2 (2) 2025/03/08 00:08
[tip: locking/core] locking/semaphore: Use wake_q to wake up processes outside lock critical section 1 (1) 2025/03/03 18:51
[syzbot] [cgroups?] possible deadlock in __run_timer_base (2) 3 (4) 2025/02/14 14:17
Re: [PATCH v3] locking/semaphore: Use wake_q to wake up processes outside lock critical section 7 (7) 2025/02/12 18:36
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream possible deadlock in __run_timer_base kernel 1 207d 203d 0/28 auto-obsoleted due to no activity on 2024/12/11 15:30

Sample crash report:
------------[ cut here ]------------
======================================================
WARNING: possible circular locking dependency detected
6.14.0-rc3-syzkaller-00295-g27102b38b8ca #0 Not tainted
------------------------------------------------------
kworker/0:5/5317 is trying to acquire lock:
ffffffff8ea14bb8 ((console_sem).lock){-.-.}-{2:2}, at: down_trylock+0x20/0xa0 kernel/locking/semaphore.c:139

but task is already holding lock:
ffff88801fc2a398 (&base->lock){-.-.}-{2:2}, at: expire_timers kernel/time/timer.c:1841 [inline]
ffff88801fc2a398 (&base->lock){-.-.}-{2:2}, at: __run_timers kernel/time/timer.c:2414 [inline]
ffff88801fc2a398 (&base->lock){-.-.}-{2:2}, at: __run_timer_base+0x672/0x8e0 kernel/time/timer.c:2426

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (&base->lock){-.-.}-{2:2}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
       lock_timer_base kernel/time/timer.c:1046 [inline]
       __mod_timer+0x24a/0x10e0 kernel/time/timer.c:1127
       queue_delayed_work_on+0x1ca/0x390 kernel/workqueue.c:2559
       psi_task_change+0xed/0x270 kernel/sched/psi.c:912
       psi_enqueue kernel/sched/stats.h:166 [inline]
       enqueue_task+0x306/0x3d0 kernel/sched/core.c:2077
       activate_task kernel/sched/core.c:2117 [inline]
       wake_up_new_task+0x576/0xc70 kernel/sched/core.c:4879
       kernel_clone+0x4ee/0x8e0 kernel/fork.c:2846
       user_mode_thread+0x144/0x1c0 kernel/fork.c:2893
       rest_init+0x23/0x300 init/main.c:708
       start_kernel+0x484/0x510 init/main.c:1099
       x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:515
       x86_64_start_kernel+0x66/0x70 arch/x86/kernel/head64.c:496
       common_startup_64+0x13e/0x147

-> #2 (&rq->__lock){-.-.}-{2:2}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378
       raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:598
       raw_spin_rq_lock kernel/sched/sched.h:1521 [inline]
       task_rq_lock+0xc6/0x360 kernel/sched/core.c:700
       cgroup_move_task+0x9b/0x5a0 kernel/sched/psi.c:1161
       css_set_move_task+0x72e/0x950 kernel/cgroup/cgroup.c:898
       cgroup_post_fork+0x284/0x8b0 kernel/cgroup/cgroup.c:6695
       copy_process+0x398a/0x3cf0 kernel/fork.c:2629
       kernel_clone+0x226/0x8e0 kernel/fork.c:2815
       user_mode_thread+0x144/0x1c0 kernel/fork.c:2893
       rest_init+0x23/0x300 init/main.c:708
       start_kernel+0x484/0x510 init/main.c:1099
       x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:515
       x86_64_start_kernel+0x66/0x70 arch/x86/kernel/head64.c:496
       common_startup_64+0x13e/0x147

-> #1 (&p->pi_lock){-.-.}-{2:2}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       __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:551 [inline]
       try_to_wake_up+0xc2/0x1470 kernel/sched/core.c:4214
       up+0x72/0x90 kernel/locking/semaphore.c:191
       __up_console_sem kernel/printk/printk.c:343 [inline]
       __console_unlock+0x123/0x1f0 kernel/printk/printk.c:2869
       __console_flush_and_unlock kernel/printk/printk.c:3271 [inline]
       console_unlock+0x18f/0x3b0 kernel/printk/printk.c:3309
       vga_remove_vgacon+0xbe/0xd0 drivers/pci/vgaarb.c:186
       virtio_gpu_pci_quirk drivers/gpu/drm/virtio/virtgpu_drv.c:62 [inline]
       virtio_gpu_probe+0x33f/0x3c0 drivers/gpu/drm/virtio/virtgpu_drv.c:93
       virtio_dev_probe+0x931/0xc80 drivers/virtio/virtio.c:341
       really_probe+0x2b9/0xad0 drivers/base/dd.c:658
       __driver_probe_device+0x1a2/0x390 drivers/base/dd.c:800
       driver_probe_device+0x50/0x430 drivers/base/dd.c:830
       __driver_attach+0x45f/0x710 drivers/base/dd.c:1216
       bus_for_each_dev+0x239/0x2b0 drivers/base/bus.c:370
       bus_add_driver+0x346/0x670 drivers/base/bus.c:678
       driver_register+0x23a/0x320 drivers/base/driver.c:249
       do_one_initcall+0x248/0x930 init/main.c:1257
       do_initcall_level+0x157/0x210 init/main.c:1319
       do_initcalls+0x71/0xd0 init/main.c:1335
       kernel_init_freeable+0x435/0x5d0 init/main.c:1568
       kernel_init+0x1d/0x2b0 init/main.c:1457
       ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

-> #0 ((console_sem).lock){-.-.}-{2:2}:
       check_prev_add kernel/locking/lockdep.c:3163 [inline]
       check_prevs_add kernel/locking/lockdep.c:3282 [inline]
       validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3906
       __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
       down_trylock+0x20/0xa0 kernel/locking/semaphore.c:139
       __down_trylock_console_sem+0x109/0x250 kernel/printk/printk.c:326
       console_trylock kernel/printk/printk.c:2852 [inline]
       console_trylock_spinning kernel/printk/printk.c:2009 [inline]
       vprintk_emit+0x3d7/0xa10 kernel/printk/printk.c:2431
       _printk+0xd5/0x120 kernel/printk/printk.c:2457
       __report_bug lib/bug.c:195 [inline]
       report_bug+0x346/0x500 lib/bug.c:219
       handle_bug+0x60/0x90 arch/x86/kernel/traps.c:285
       exc_invalid_op+0x1a/0x50 arch/x86/kernel/traps.c:309
       asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:621
       expire_timers kernel/time/timer.c:1827 [inline]
       __run_timers kernel/time/timer.c:2414 [inline]
       __run_timer_base+0x6f4/0x8e0 kernel/time/timer.c:2426
       run_timer_base kernel/time/timer.c:2435 [inline]
       run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2445
       handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:561
       __do_softirq kernel/softirq.c:595 [inline]
       invoke_softirq kernel/softirq.c:435 [inline]
       __irq_exit_rcu+0xf7/0x220 kernel/softirq.c:662
       irq_exit_rcu+0x9/0x30 kernel/softirq.c:678
       instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
       sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049
       asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
       delay_loop+0x20/0x30 arch/x86/lib/delay.c:44
       udelay include/asm-generic/delay.h:64 [inline]
       try_check_zero+0x43b/0x4a0 kernel/rcu/srcutree.c:1112
       srcu_advance_state kernel/rcu/srcutree.c:1742 [inline]
       process_srcu+0x242/0x12e0 kernel/rcu/srcutree.c:1851
       process_one_work kernel/workqueue.c:3236 [inline]
       process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3317
       worker_thread+0x870/0xd30 kernel/workqueue.c:3398
       kthread+0x7a9/0x920 kernel/kthread.c:464
       ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

other info that might help us debug this:

Chain exists of:
  (console_sem).lock --> &rq->__lock --> &base->lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&base->lock);
                               lock(&rq->__lock);
                               lock(&base->lock);
  lock((console_sem).lock);

 *** DEADLOCK ***

4 locks held by kworker/0:5/5317:
 #0: ffff88801b0c6d48 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
 #0: ffff88801b0c6d48 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3317
 #1: ffffc9000d24fc60 ((work_completion)(&(&ssp->srcu_sup->work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
 #1: ffffc9000d24fc60 ((work_completion)(&(&ssp->srcu_sup->work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3317
 #2: ffffffff8ec521b8 (&ssp->srcu_sup->srcu_gp_mutex){+.+.}-{4:4}, at: srcu_advance_state kernel/rcu/srcutree.c:1691 [inline]
 #2: ffffffff8ec521b8 (&ssp->srcu_sup->srcu_gp_mutex){+.+.}-{4:4}, at: process_srcu+0x6b/0x12e0 kernel/rcu/srcutree.c:1851
 #3: ffff88801fc2a398 (&base->lock){-.-.}-{2:2}, at: expire_timers kernel/time/timer.c:1841 [inline]
 #3: ffff88801fc2a398 (&base->lock){-.-.}-{2:2}, at: __run_timers kernel/time/timer.c:2414 [inline]
 #3: ffff88801fc2a398 (&base->lock){-.-.}-{2:2}, at: __run_timer_base+0x672/0x8e0 kernel/time/timer.c:2426

stack backtrace:
CPU: 0 UID: 0 PID: 5317 Comm: kworker/0:5 Not tainted 6.14.0-rc3-syzkaller-00295-g27102b38b8ca #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: rcu_gp process_srcu
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2076
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2208
 check_prev_add kernel/locking/lockdep.c:3163 [inline]
 check_prevs_add kernel/locking/lockdep.c:3282 [inline]
 validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3906
 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
 down_trylock+0x20/0xa0 kernel/locking/semaphore.c:139
 __down_trylock_console_sem+0x109/0x250 kernel/printk/printk.c:326
 console_trylock kernel/printk/printk.c:2852 [inline]
 console_trylock_spinning kernel/printk/printk.c:2009 [inline]
 vprintk_emit+0x3d7/0xa10 kernel/printk/printk.c:2431
 _printk+0xd5/0x120 kernel/printk/printk.c:2457
 __report_bug lib/bug.c:195 [inline]
 report_bug+0x346/0x500 lib/bug.c:219
 handle_bug+0x60/0x90 arch/x86/kernel/traps.c:285
 exc_invalid_op+0x1a/0x50 arch/x86/kernel/traps.c:309
 asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:621
RIP: 0010:expire_timers kernel/time/timer.c:1827 [inline]
RIP: 0010:__run_timers kernel/time/timer.c:2414 [inline]
RIP: 0010:__run_timer_base+0x6f4/0x8e0 kernel/time/timer.c:2426
Code: 24 38 42 80 3c 30 00 74 08 4c 89 ef e8 75 8e 7a 00 4d 8b 7d 00 4d 85 ff 74 33 e8 27 54 13 00 e9 dd fe ff ff e8 1d 54 13 00 90 <0f> 0b 90 eb ae 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c 25 ff ff ff
RSP: 0018:ffffc90000007ca0 EFLAGS: 00010046
RAX: ffffffff81ae69e3 RBX: ffff88804441b4b8 RCX: ffff8880006c0000
RDX: 0000000000000100 RSI: ffffffff8c80eee0 RDI: ffffffff8c80eea0
RBP: ffffc90000007df0 R08: ffffffff81aea3e4 R09: 1ffffffff2079d8e
R10: dffffc0000000000 R11: fffffbfff2079d8f R12: 0000000000000000
R13: ffffc90000007d48 R14: dffffc0000000000 R15: ffff88804441b4a0
 run_timer_base kernel/time/timer.c:2435 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2445
 handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:561
 __do_softirq kernel/softirq.c:595 [inline]
 invoke_softirq kernel/softirq.c:435 [inline]
 __irq_exit_rcu+0xf7/0x220 kernel/softirq.c:662
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:678
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:delay_loop+0x20/0x30 arch/x86/lib/delay.c:44
Code: 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 89 f8 48 85 c0 74 19 eb 02 66 90 eb 0e 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 <48> ff c8 75 fb 48 ff c8 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90
RSP: 0018:ffffc9000d24f9a8 EFLAGS: 00000206
RAX: 000000000000270c RBX: ffff88801fc39060 RCX: 0000000000000000
RDX: 00000000000036b0 RSI: 0000000000000008 RDI: 00000000000036b1
RBP: dffffc0000000000 R08: ffff88801fc39047 R09: 1ffff11003f87208
R10: dffffc0000000000 R11: ffffffff8c0716d0 R12: ffffffff8ec52028
R13: 0000000000000001 R14: 0000000000000001 R15: 0000000000000000
 udelay include/asm-generic/delay.h:64 [inline]
 try_check_zero+0x43b/0x4a0 kernel/rcu/srcutree.c:1112
 srcu_advance_state kernel/rcu/srcutree.c:1742 [inline]
 process_srcu+0x242/0x12e0 kernel/rcu/srcutree.c:1851
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3317
 worker_thread+0x870/0xd30 kernel/workqueue.c:3398
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
WARNING: CPU: 0 PID: 5317 at kernel/time/timer.c:1827 expire_timers kernel/time/timer.c:1827 [inline]
WARNING: CPU: 0 PID: 5317 at kernel/time/timer.c:1827 __run_timers kernel/time/timer.c:2414 [inline]
WARNING: CPU: 0 PID: 5317 at kernel/time/timer.c:1827 __run_timer_base+0x6f4/0x8e0 kernel/time/timer.c:2426
Modules linked in:
CPU: 0 UID: 0 PID: 5317 Comm: kworker/0:5 Not tainted 6.14.0-rc3-syzkaller-00295-g27102b38b8ca #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: rcu_gp process_srcu
RIP: 0010:expire_timers kernel/time/timer.c:1827 [inline]
RIP: 0010:__run_timers kernel/time/timer.c:2414 [inline]
RIP: 0010:__run_timer_base+0x6f4/0x8e0 kernel/time/timer.c:2426
Code: 24 38 42 80 3c 30 00 74 08 4c 89 ef e8 75 8e 7a 00 4d 8b 7d 00 4d 85 ff 74 33 e8 27 54 13 00 e9 dd fe ff ff e8 1d 54 13 00 90 <0f> 0b 90 eb ae 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c 25 ff ff ff
RSP: 0018:ffffc90000007ca0 EFLAGS: 00010046
RAX: ffffffff81ae69e3 RBX: ffff88804441b4b8 RCX: ffff8880006c0000
RDX: 0000000000000100 RSI: ffffffff8c80eee0 RDI: ffffffff8c80eea0
RBP: ffffc90000007df0 R08: ffffffff81aea3e4 R09: 1ffffffff2079d8e
R10: dffffc0000000000 R11: fffffbfff2079d8f R12: 0000000000000000
R13: ffffc90000007d48 R14: dffffc0000000000 R15: ffff88804441b4a0
FS:  0000000000000000(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000561f89eb90a8 CR3: 0000000035e72000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 run_timer_base kernel/time/timer.c:2435 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2445
 handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:561
 __do_softirq kernel/softirq.c:595 [inline]
 invoke_softirq kernel/softirq.c:435 [inline]
 __irq_exit_rcu+0xf7/0x220 kernel/softirq.c:662
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:678
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:delay_loop+0x20/0x30 arch/x86/lib/delay.c:44
Code: 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 89 f8 48 85 c0 74 19 eb 02 66 90 eb 0e 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 <48> ff c8 75 fb 48 ff c8 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90
RSP: 0018:ffffc9000d24f9a8 EFLAGS: 00000206
RAX: 000000000000270c RBX: ffff88801fc39060 RCX: 0000000000000000
RDX: 00000000000036b0 RSI: 0000000000000008 RDI: 00000000000036b1
RBP: dffffc0000000000 R08: ffff88801fc39047 R09: 1ffff11003f87208
R10: dffffc0000000000 R11: ffffffff8c0716d0 R12: ffffffff8ec52028
R13: 0000000000000001 R14: 0000000000000001 R15: 0000000000000000
 udelay include/asm-generic/delay.h:64 [inline]
 try_check_zero+0x43b/0x4a0 kernel/rcu/srcutree.c:1112
 srcu_advance_state kernel/rcu/srcutree.c:1742 [inline]
 process_srcu+0x242/0x12e0 kernel/rcu/srcutree.c:1851
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3317
 worker_thread+0x870/0xd30 kernel/workqueue.c:3398
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
----------------
Code disassembly (best guess):
   0:	90                   	nop
   1:	90                   	nop
   2:	90                   	nop
   3:	90                   	nop
   4:	90                   	nop
   5:	90                   	nop
   6:	90                   	nop
   7:	90                   	nop
   8:	90                   	nop
   9:	90                   	nop
   a:	f3 0f 1e fa          	endbr64
   e:	48 89 f8             	mov    %rdi,%rax
  11:	48 85 c0             	test   %rax,%rax
  14:	74 19                	je     0x2f
  16:	eb 02                	jmp    0x1a
  18:	66 90                	xchg   %ax,%ax
  1a:	eb 0e                	jmp    0x2a
  1c:	66 2e 0f 1f 84 00 00 	cs nopw 0x0(%rax,%rax,1)
  23:	00 00 00
  26:	0f 1f 40 00          	nopl   0x0(%rax)
* 2a:	48 ff c8             	dec    %rax <-- trapping instruction
  2d:	75 fb                	jne    0x2a
  2f:	48 ff c8             	dec    %rax
  32:	c3                   	ret
  33:	cc                   	int3
  34:	cc                   	int3
  35:	cc                   	int3
  36:	cc                   	int3
  37:	0f 1f 00             	nopl   (%rax)
  3a:	90                   	nop
  3b:	90                   	nop
  3c:	90                   	nop
  3d:	90                   	nop
  3e:	90                   	nop
  3f:	90                   	nop

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/02/23 16:10 upstream 27102b38b8ca d34966d1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root possible deadlock in __run_timer_base
2025/02/05 20:31 upstream 92514ef226f5 577d049b .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root possible deadlock in __run_timer_base
* Struck through repros no longer work on HEAD.