INFO: rcu detected stall in __run_timers (2)

Status: upstream: reported on 2025/09/03 11:07
Reported-by: syzbot+cd14d7355b2f09d8aa58@syzkaller.appspotmail.com
First crash: 400d, last: 19d
▶ ▼ Similar bugs (18)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in __run_timers (8) prio:normal kernel 1 1 159d 159d 0/29 auto-obsoleted due to no activity on 2026/07/31 00:54
upstream INFO: rcu detected stall in __run_timers (4) tomoyo 1 4 2436d 2451d 0/29 auto-closed as invalid on 2020/05/06 02:55
linux-5.15 INFO: rcu detected stall in __run_timers 1 1 1270d 1270d 0/3 auto-obsoleted due to no activity on 2023/08/15 19:18
upstream INFO: rcu detected stall in __run_timers net 1 2 2951d 2953d 0/29 closed as invalid on 2018/09/11 10:51
upstream INFO: rcu detected stall in __run_timers (2) block 1 58 2823d 2947d 0/29 closed as dup on 2019/01/02 16:40
linux-6.1 INFO: rcu detected stall in __run_timers (2) origin:upstream 1 syz error 4 38d 361d 0/3 upstream: reported syz repro on 2025/10/12 10:55
upstream INFO: rcu detected stall in __run_timers (7) kernfs 1 25 759d 863d 0/29 auto-obsoleted due to no activity on 2024/11/08 17:44
linux-6.1 INFO: rcu detected stall in __run_timers 1 1 718d 718d 0/3 auto-obsoleted due to no activity on 2025/01/28 16:20
upstream INFO: rcu detected stall in __run_timers (6) kernel 1 2 1679d 1695d 0/29 auto-closed as invalid on 2022/06/02 21:46
linux-6.6 INFO: rcu detected stall in __run_timers 1 2 81d 120d 0/2 upstream: reported on 2026/06/10 07:15
upstream INFO: rcu detected stall in __run_timers (3) mm 1 4 2563d 2585d 0/29 auto-closed as invalid on 2019/12/31 08:04
upstream INFO: rcu detected stall in __run_timers (5) kernel 1 syz, C error error 63 1710d 2224d 0/29 closed as invalid on 2022/02/08 10:39
android-5-10 BUG: soft lockup in __run_timers 1 2 779d 848d 0/2 auto-obsoleted due to no activity on 2024/11/18 04:44
android-5-15 BUG: soft lockup in __run_timers (2) 1 1 12d 12d 0/2 premoderation: reported on 2026/09/26 07:23
android-54 BUG: soft lockup in __run_timers 1 1 832d 832d 0/2 auto-obsoleted due to no activity on 2024/09/26 00:22
android-5-15 BUG: soft lockup in __run_timers 1 1 750d 750d 0/2 auto-obsoleted due to no activity on 2024/12/16 23:50
upstream BUG: soft lockup in __run_timers kernel 1 1 1341d 1337d 0/29 auto-obsoleted due to no activity on 2023/05/06 12:08
android-54 BUG: soft lockup in __run_timers (2) 1 2 552d 614d 0/2 auto-obsoleted due to no activity on 2025/07/03 11:27

Sample crash report:
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (1 GPs behind) idle=241/1/0x4000000000000000 softirq=20962/20965 fqs=4062 
	(t=10500 jiffies g=28469 q=7642)
NMI backtrace for cpu 0
CPU: 0 PID: 8019 Comm: syz.8.731 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <IRQ>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
 rcu_dump_cpu_stacks+0x22d/0x380 kernel/rcu/tree_stall.h:349
 print_cpu_stall+0x31f/0x5f0 kernel/rcu/tree_stall.h:633
 check_cpu_stall kernel/rcu/tree_stall.h:727 [inline]
 rcu_pending kernel/rcu/tree.c:3936 [inline]
 rcu_sched_clock_irq+0x6ec/0x1120 kernel/rcu/tree.c:2619
 update_process_times+0x193/0x200 kernel/time/timer.c:2021
 tick_sched_handle kernel/time/tick-sched.c:254 [inline]
 tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x4b0/0xb60 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x397/0x8b0 kernel/time/hrtimer.c:1811
 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+0x4d/0xc0 arch/x86/kernel/apic/apic.c:1108
 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: 00 00 00 66 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 2e c4 92 f7 48 89 df e8 66 9b 93 f7 e8 a1 97 b4 f7 fb bf 01 00 00 00 <e8> b6 b0 87 f7 65 8b 05 e7 c6 37 76 85 c0 74 02 5b c3 e8 24 d4 35
RSP: 0018:ffffc90000007c70 EFLAGS: 00000282
RAX: 0fdad0d0cbf29700 RBX: ffff8880b90280c0 RCX: 0fdad0d0cbf29700
RDX: dffffc0000000000 RSI: ffffffff8a2b2be0 RDI: 0000000000000001
RBP: ffffc90000007df0 R08: ffffffff901f11cf R09: 1ffffffff203e239
R10: dffffc0000000000 R11: fffffbfff203e23a R12: 1ffff11017205020
R13: ffff8880b90280c0 R14: ffff88801c1456f8 R15: ffffc90000007d40
 expire_timers kernel/time/timer.c:1698 [inline]
 __run_timers+0x55c/0x810 kernel/time/timer.c:1970
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1983
 handle_softirqs+0x336/0x830 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 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:generic_exec_single+0x37d/0x470 kernel/smp.c:532
Code: df eb 27 e8 f5 82 0b 00 0f 0b e9 ac fd ff ff e8 e9 82 0b 00 e8 34 a3 53 08 48 85 db 0f 84 5c ff ff ff e8 d6 82 0b 00 fb 31 c0 <48> c7 44 24 20 0e 36 e0 45 4b c7 44 3d 00 00 00 00 00 43 c7 44 3d
RSP: 0018:ffffc90003fffa60 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000200 RCX: 0000000000080000
RDX: ffffc90011e16000 RSI: 0000000000002415 RDI: 0000000000002416
RBP: ffffc90003fffb30 R08: ffffffff901f11cf R09: 1ffffffff203e239
R10: dffffc0000000000 R11: fffffbfff203e23a R12: ffffc90003fffb88
R13: 1ffff920007fff50 R14: 0000000000000000 R15: dffffc0000000000
 smp_call_function_single+0x202/0x4c0 kernel/smp.c:755
 task_function_call kernel/events/core.c:120 [inline]
 perf_install_in_context+0x5cf/0x930 kernel/events/core.c:3026
 __do_sys_perf_event_open kernel/events/core.c:12803 [inline]
 __se_sys_perf_event_open+0x12b3/0x1bb0 kernel/events/core.c:12397
 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: 0033:0x7fcfb7e6a159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fcfb6080028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007fcfb80f2180 RCX: 00007fcfb7e6a159
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000480
RBP: 00007fcfb7f0106b R08: 0000000000000002 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007fcfb80f2218 R14: 00007fcfb80f2180 R15: 00007ffca79e3478
 </TASK>

Crashes (12):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/19 04:33 linux-5.15.y 0248c33e835e 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in __run_timers
2026/09/07 02:56 linux-5.15.y 0996e0926f6b 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in __run_timers
2026/08/21 18:06 linux-5.15.y 0eb903b5b519 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in __run_timers
2026/07/30 11:03 linux-5.15.y 674f684f7c61 2377cd3d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in __run_timers
2026/06/25 03:38 linux-5.15.y eceeec79dbc6 302586aa .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in __run_timers
2026/05/14 13:19 linux-5.15.y de8dfb3f0278 6ccb967e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in __run_timers
2026/04/27 17:20 linux-5.15.y b9d57c40a767 0f700595 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in __run_timers
2026/04/26 08:42 linux-5.15.y b9d57c40a767 9c2d0995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in __run_timers
2026/01/24 21:23 linux-5.15.y 9eec9a14ee10 40acda8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in __run_timers
2025/12/01 14:20 linux-5.15.y cc5ec8769306 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in __run_timers
2025/10/11 12:15 linux-5.15.y 29e53a5b1c4f ff1712fe .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in __run_timers
2025/09/03 11:07 linux-5.15.y 01879f56bdde 96a211bc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in __run_timers
* Struck through repros no longer work on HEAD.