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INFO: rcu detected stall in sys_timerfd_settime (4)

Status: upstream: reported on 2025/06/06 11:45
Reported-by: syzbot+2327d54f806b6e01214b@syzkaller.appspotmail.com
First crash: 6d20h, last: 1d13h
▶ ▼ Similar bugs (11)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 INFO: rcu detected stall in sys_timerfd_settime (2) 3 311d 351d 0/3 auto-obsoleted due to no activity on 2024/11/14 05:49
upstream INFO: rcu detected stall in sys_timerfd_settime fs 3 1308d 1376d 0/28 closed as invalid on 2022/02/08 09:50
upstream INFO: rcu detected stall in sys_timerfd_settime (4) fs 1 425d 425d 0/28 auto-obsoleted due to no activity on 2024/06/12 13:14
upstream INFO: rcu detected stall in sys_timerfd_settime (2) net 1 878d 878d 0/28 auto-obsoleted due to no activity on 2023/04/25 06:19
linux-6.1 INFO: rcu detected stall in sys_timerfd_settime (3) 1 58d 58d 0/3 upstream: reported on 2025/04/16 01:08
upstream INFO: rcu detected stall in sys_timerfd_settime (3) fs 2 520d 572d 0/28 auto-obsoleted due to no activity on 2024/04/09 00:01
upstream INFO: rcu detected stall in sys_timerfd_settime (5) fs 17 124d 329d 0/28 auto-obsoleted due to no activity on 2025/05/09 08:53
linux-5.15 INFO: rcu detected stall in sys_timerfd_settime 1 730d 730d 0/3 auto-obsoleted due to no activity on 2023/09/22 02:06
linux-6.1 INFO: rcu detected stall in sys_timerfd_settime 1 722d 722d 0/3 auto-obsoleted due to no activity on 2023/09/29 23:03
linux-5.15 INFO: rcu detected stall in sys_timerfd_settime (3) 1 204d 204d 0/3 auto-obsoleted due to no activity on 2025/03/01 03:09
linux-6.1 INFO: rcu detected stall in sys_timerfd_settime (2) 1 176d 176d 0/3 auto-obsoleted due to no activity on 2025/03/29 01:59

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (0 ticks this GP) idle=ecf/1/0x4000000000000000 softirq=50515/50515 fqs=0 
	(detected by 1, t=10506 jiffies, g=71941, q=651)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 15757 Comm: syz.0.4610 Not tainted 5.15.185-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:mark_lock+0xfd/0x320 kernel/locking/lockdep.c:4610
Code: 83 c7 50 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff e8 24 9d 60 00 b8 01 00 00 00 45 85 27 74 50 48 83 c4 08 5b 41 5c <41> 5d 41 5e 41 5f 5d c3 e8 f6 bd 7b 02 85 c0 74 c1 48 c7 c0 88 df
RSP: 0018:ffffc900000078b8 EFLAGS: 00000082
RAX: 0000000000000001 RBX: ffff88802b9b6428 RCX: ffffffff815c9cb4
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8ff9b0c8
RBP: 0000000000000000 R08: dffffc0000000000 R09: fffffbfff1ff361a
R10: fffffbfff1ff361a R11: 1ffffffff1ff3619 R12: ffff88802b9b6450
R13: dffffc0000000000 R14: ffff88802b9b6430 R15: ffffffff8f927590
FS:  00007f78e9baa6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdf91405000 CR3: 000000007afff000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 mark_usage kernel/locking/lockdep.c:4483 [inline]
 __lock_acquire+0xc11/0x7c60 kernel/locking/lockdep.c:4966
 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline]
 _raw_spin_lock_irq+0x9f/0xe0 kernel/locking/spinlock.c:170
 __run_hrtimer kernel/time/hrtimer.c:1694 [inline]
 __hrtimer_run_queues+0x5ff/0xc40 kernel/time/hrtimer.c:1754
 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202
Code: f6 ff 0f 1f 00 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 8e 9a b1 f7 48 89 df e8 56 6f b2 f7 e8 a1 13 d3 f7 fb bf 01 00 00 00 <e8> 86 93 a6 f7 65 8b 05 27 a3 57 76 85 c0 74 02 5b c3 e8 d4 ad 55
RSP: 0018:ffffc9000328fd20 EFLAGS: 00000282
RAX: 5d83ea0dc0b2c400 RBX: ffff88805fd6bc88 RCX: 5d83ea0dc0b2c400
RDX: dffffc0000000000 RSI: ffffffff8a0b11c0 RDI: 0000000000000001
RBP: 7fffffffffffffff R08: dffffc0000000000 R09: ffffed100bfad792
R10: ffffed100bfad792 R11: 1ffff1100bfad791 R12: 1ffff1100bfad790
R13: ffff88805fd6bc00 R14: ffff88801f353181 R15: 7fffffffffffffff
 spin_unlock_irq include/linux/spinlock.h:413 [inline]
 do_timerfd_settime+0xe3a/0x1080 fs/timerfd.c:521
 __do_sys_timerfd_settime fs/timerfd.c:567 [inline]
 __se_sys_timerfd_settime fs/timerfd.c:558 [inline]
 __x64_sys_timerfd_settime+0x15e/0x210 fs/timerfd.c:558
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f78ebd42929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f78e9baa038 EFLAGS: 00000246 ORIG_RAX: 000000000000011e
RAX: ffffffffffffffda RBX: 00007f78ebf69fa0 RCX: 00007f78ebd42929
RDX: 0000200000000000 RSI: 0000000000000003 RDI: 0000000000000003
RBP: 00007f78ebdc4b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f78ebf69fa0 R15: 00007fff26e96c08
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10505 jiffies! g71941 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=31038
rcu: rcu_preempt kthread starved for 10506 jiffies! g71941 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:I stack:28032 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1e0 kernel/sched/core.c:6459
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 15757 Comm: syz.0.4610 Not tainted 5.15.185-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4702 [inline]
RIP: 0010:__lock_acquire+0x6e2/0x7c60 kernel/locking/lockdep.c:4962
Code: 44 89 f0 83 c0 fe 0f 88 70 01 00 00 44 89 fb 81 e3 ff ff ff 7f 83 f8 31 73 43 48 8d 04 9b 49 8d 5c c5 00 48 89 d8 48 c1 e8 03 <42> 0f b6 04 00 84 c0 75 45 8b 1b 48 8b 44 24 58 42 0f b6 04 00 84
RSP: 0018:ffffc90000007860 EFLAGS: 00000802
RAX: 1ffff11005736c8a RBX: ffff88802b9b6450 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8ff9b0c0
RBP: ffffc90000007ab0 R08: dffffc0000000000 R09: fffffbfff1ff3619
R10: fffffbfff1ff3619 R11: 1ffffffff1ff3618 R12: 0000000000000000
R13: ffff88802b9b6450 R14: 0000000000000002 R15: 0000000000000000
FS:  00007f78e9baa6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdf91405000 CR3: 000000007afff000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162
 debug_object_activate+0x65/0x480 lib/debugobjects.c:694
 debug_hrtimer_activate kernel/time/hrtimer.c:410 [inline]
 debug_activate kernel/time/hrtimer.c:465 [inline]
 enqueue_hrtimer+0x30/0x370 kernel/time/hrtimer.c:1074
 __run_hrtimer kernel/time/hrtimer.c:1707 [inline]
 __hrtimer_run_queues+0x65a/0xc40 kernel/time/hrtimer.c:1754
 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202
Code: f6 ff 0f 1f 00 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 8e 9a b1 f7 48 89 df e8 56 6f b2 f7 e8 a1 13 d3 f7 fb bf 01 00 00 00 <e8> 86 93 a6 f7 65 8b 05 27 a3 57 76 85 c0 74 02 5b c3 e8 d4 ad 55
RSP: 0018:ffffc9000328fd20 EFLAGS: 00000282
RAX: 5d83ea0dc0b2c400 RBX: ffff88805fd6bc88 RCX: 5d83ea0dc0b2c400
RDX: dffffc0000000000 RSI: ffffffff8a0b11c0 RDI: 0000000000000001
RBP: 7fffffffffffffff R08: dffffc0000000000 R09: ffffed100bfad792
R10: ffffed100bfad792 R11: 1ffff1100bfad791 R12: 1ffff1100bfad790
R13: ffff88805fd6bc00 R14: ffff88801f353181 R15: 7fffffffffffffff
 spin_unlock_irq include/linux/spinlock.h:413 [inline]
 do_timerfd_settime+0xe3a/0x1080 fs/timerfd.c:521
 __do_sys_timerfd_settime fs/timerfd.c:567 [inline]
 __se_sys_timerfd_settime fs/timerfd.c:558 [inline]
 __x64_sys_timerfd_settime+0x15e/0x210 fs/timerfd.c:558
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f78ebd42929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f78e9baa038 EFLAGS: 00000246 ORIG_RAX: 000000000000011e
RAX: ffffffffffffffda RBX: 00007f78ebf69fa0 RCX: 00007f78ebd42929
RDX: 0000200000000000 RSI: 0000000000000003 RDI: 0000000000000003
RBP: 00007f78ebdc4b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f78ebf69fa0 R15: 00007fff26e96c08
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/06/11 18:36 linux-5.15.y 1c700860e8bc 98683f8f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_timerfd_settime
2025/06/06 11:44 linux-5.15.y 1c700860e8bc 9fa58bba .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_timerfd_settime
* Struck through repros no longer work on HEAD.