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INFO: rcu detected stall in call_timer_fn

Status: upstream: reported on 2025/09/20 00:57
Reported-by: syzbot+c4956fba553abbcc9f30@syzkaller.appspotmail.com
First crash: 131d, last: 4d03h
▶ ▼ Similar bugs (13)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream BUG: soft lockup in call_timer_fn net mm 1 19 548d 590d 0/29 auto-obsoleted due to no activity on 2024/10/08 10:43
linux-6.1 INFO: rcu detected stall in call_timer_fn 1 2 473d 545d 0/3 auto-obsoleted due to no activity on 2025/01/21 02:15
linux-4.19 INFO: rcu detected stall in call_timer_fn (2) 1 16 1912d 2186d 0/1 auto-closed as invalid on 2021/03/04 12:30
upstream INFO: rcu detected stall in call_timer_fn (5) net input usb 1 C 9 202d 336d 0/29 upstream: reported C repro on 2025/02/27 04:11
linux-4.14 INFO: rcu detected stall in call_timer_fn (2) 1 1 1974d 1974d 0/1 auto-closed as invalid on 2020/12/31 22:00
upstream INFO: rcu detected stall in call_timer_fn (2) kernel 1 C done error 47 1471d 2327d 0/29 closed as invalid on 2022/02/08 10:46
upstream INFO: rcu detected stall in call_timer_fn bpf net 1 2 2665d 2677d 0/29 closed as dup on 2019/01/02 16:26
linux-4.19 INFO: rcu detected stall in call_timer_fn 1 1 2325d 2325d 0/1 auto-closed as invalid on 2020/01/15 18:43
linux-4.14 INFO: rcu detected stall in call_timer_fn 1 5 2099d 2218d 0/1 auto-closed as invalid on 2020/08/29 09:07
upstream INFO: rcu detected stall in call_timer_fn (4) mm 1 1 729d 729d 0/29 auto-obsoleted due to no activity on 2024/03/31 10:44
upstream INFO: rcu detected stall in call_timer_fn (3) kernel 1 3 1210d 1226d 0/29 auto-obsoleted due to no activity on 2023/01/12 18:45
linux-4.19 BUG: soft lockup in call_timer_fn 1 C error 31 1061d 1664d 0/1 upstream: reported C repro on 2021/07/10 02:48
upstream BUG: soft lockup in call_timer_fn (2) trace 1 1 474d 470d 0/29 auto-obsoleted due to no activity on 2025/01/10 05:15

Sample crash report:
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (1 GPs behind) idle=9fb/1/0x4000000000000000 softirq=31827/31828 fqs=4473 
	(t=10500 jiffies g=44149 q=433)
NMI backtrace for cpu 0
CPU: 0 PID: 12524 Comm: syz.6.2073 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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+0x22f/0x380 kernel/rcu/tree_stall.h:349
 print_cpu_stall+0x31d/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+0x6ea/0x1120 kernel/rcu/tree.c:2619
 update_process_times+0x193/0x200 kernel/time/timer.c:1818
 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+0x4ad/0xb70 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x3bb/0x8d0 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:lock_acquire+0x208/0x400 kernel/locking/lockdep.c:5627
Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3d 04 f8 0f 85 f1 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 43 c7 44 3d 08 00 00 00 00 65 48 8b 04
RSP: 0018:ffffc90000007a80 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 738b7834e2181600
RDX: 0000000000000000 RSI: ffffffff8a2b3a20 RDI: ffffffff8a79f780
RBP: ffffc90000007b88 R08: dffffc0000000000 R09: 1ffffffff203a232
R10: dffffc0000000000 R11: fffffbfff203a233 R12: ffffc90000007be0
R13: 1ffff92000000f5c R14: 0000000000000246 R15: dffffc0000000000
 call_timer_fn+0xe6/0x540 kernel/time/timer.c:1448
 expire_timers kernel/time/timer.c:1496 [inline]
 __run_timers+0x53a/0x7f0 kernel/time/timer.c:1767
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780
 handle_softirqs+0x339/0x830 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+0x373/0x460 kernel/smp.c:532
Code: df eb 27 e8 7f 6c 0b 00 0f 0b e9 b6 fd ff ff e8 73 6c 0b 00 e8 9e 35 4e 08 48 85 db 0f 84 5c ff ff ff e8 60 6c 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:ffffc9000352fa60 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000200 RCX: 0000000000080000
RDX: ffffc90015287000 RSI: 000000000000342e RDI: 000000000000342f
RBP: ffffc9000352fb30 R08: ffffffff901d11cf R09: 1ffffffff203a239
R10: dffffc0000000000 R11: fffffbfff203a23a R12: ffffc9000352fb88
R13: 1ffff920006a5f50 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+0x5c7/0x920 kernel/events/core.c:3016
 __do_sys_perf_event_open kernel/events/core.c:12793 [inline]
 __se_sys_perf_event_open+0x12b3/0x1bb0 kernel/events/core.c:12387
 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: 0033:0x7fc63d649cb9
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:00007fc63b884028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007fc63d8c5090 RCX: 00007fc63d649cb9
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000480
RBP: 00007fc63d6b7bf7 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc63d8c5128 R14: 00007fc63d8c5090 R15: 00007ffd153bc368
 </TASK>

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/25 11:13 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 call_timer_fn
2025/11/30 15:21 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 call_timer_fn
2025/11/30 11:57 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 call_timer_fn
2025/10/23 14:22 linux-5.15.y ac56c046adf4 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in call_timer_fn
2025/09/20 00:57 linux-5.15.y 43bb85222e53 67c37560 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in call_timer_fn
* Struck through repros no longer work on HEAD.