INFO: rcu detected stall in call_timer_fn (2)

Status: auto-closed as invalid on 2021/03/04 12:30
Reported-by: syzbot+38f08ac9d2a051c22ee4@syzkaller.appspotmail.com
First crash: 2374d, last: 2100d
▶ ▼ 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 736d 779d 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 661d 733d 0/3 auto-obsoleted due to no activity on 2025/01/21 02:15
upstream INFO: rcu detected stall in call_timer_fn (5) net input usb 1 syz, C 9 391d 524d 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 2163d 2163d 0/1 auto-closed as invalid on 2020/12/31 22:00
linux-5.15 INFO: rcu detected stall in call_timer_fn 1 10 20d 319d 0/3 upstream: reported on 2025/09/20 00:57
upstream INFO: rcu detected stall in call_timer_fn (2) kernel 1 syz, C done error 47 1659d 2516d 0/29 closed as invalid on 2022/02/08 10:46
upstream INFO: rcu detected stall in call_timer_fn bpf net 1 2 2853d 2866d 0/29 closed as dup on 2019/01/02 16:26
linux-4.19 INFO: rcu detected stall in call_timer_fn 1 1 2514d 2514d 0/1 auto-closed as invalid on 2020/01/15 18:43
linux-6.1 INFO: rcu detected stall in call_timer_fn (2) 1 2 157d 177d 0/3 auto-obsoleted due to no activity on 2026/06/09 18:18
linux-4.14 INFO: rcu detected stall in call_timer_fn 1 5 2287d 2407d 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 917d 917d 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 1399d 1414d 0/29 auto-obsoleted due to no activity on 2023/01/12 18:45
linux-6.1 INFO: rcu detected stall in call_timer_fn (3) 1 2 13d 26d 0/3 upstream: reported on 2026/07/10 22:14

Sample crash report:
EXT4-fs (loop3): mounted filesystem without journal. Opts: ,errors=continue
EXT4-fs (loop2): mounted filesystem without journal. Opts: ,errors=continue
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (10500 ticks this GP) idle=082/1/0x4000000000000004 softirq=296950/296950 fqs=1 
rcu: 	 (t=10500 jiffies g=362201 q=266)
rcu: rcu_preempt kthread starved for 10488 jiffies! g362201 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: RCU grace-period kthread stack dump:
rcu_preempt     R  running task    28880    10      2 0x80000000
Call Trace:
 context_switch kernel/sched/core.c:2828 [inline]
 __schedule+0x887/0x2040 kernel/sched/core.c:3517
 schedule+0x8d/0x1b0 kernel/sched/core.c:3561
 schedule_timeout+0x4cf/0xfe0 kernel/time/timer.c:1825
 rcu_gp_kthread+0xdad/0x21c0 kernel/rcu/tree.c:2202
 kthread+0x33f/0x460 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
NMI backtrace for cpu 1
CPU: 1 PID: 31196 Comm: syz-executor.3 Not tainted 4.19.154-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fc/0x2fe lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1a6/0x1eb lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x15f/0x19c kernel/rcu/tree.c:1340
 print_cpu_stall kernel/rcu/tree.c:1478 [inline]
 check_cpu_stall kernel/rcu/tree.c:1550 [inline]
 __rcu_pending kernel/rcu/tree.c:3293 [inline]
 rcu_pending kernel/rcu/tree.c:3336 [inline]
 rcu_check_callbacks.cold+0x62d/0xe19 kernel/rcu/tree.c:2682
 update_process_times+0x2a/0xb0 kernel/time/timer.c:1650
 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:168
 tick_sched_timer+0xfc/0x290 kernel/time/tick-sched.c:1278
 __run_hrtimer kernel/time/hrtimer.c:1401 [inline]
 __hrtimer_run_queues+0x3f6/0xe60 kernel/time/hrtimer.c:1463
 hrtimer_interrupt+0x32a/0x930 kernel/time/hrtimer.c:1521
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1067 [inline]
 smp_apic_timer_interrupt+0x10c/0x550 arch/x86/kernel/apic/apic.c:1092
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:789 [inline]
RIP: 0010:lock_acquire+0x1ec/0x3c0 kernel/locking/lockdep.c:3910
Code: 08 00 00 00 00 00 00 48 c1 e8 03 80 3c 10 00 0f 85 b7 01 00 00 48 83 3d e9 e1 a4 08 00 0f 84 2a 01 00 00 48 8b 7c 24 08 57 9d <0f> 1f 44 00 00 48 83 c4 18 5b 5d 41 5c 41 5d 41 5e 41 5f c3 65 8b
RSP: 0018:ffff8880ba107cc0 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff13e3001 RBX: ffff88801b5de600 RCX: 0000000000003438
RDX: dffffc0000000000 RSI: 000000007555d6b6 RDI: 0000000000000286
RBP: ffff8880ba107d48 R08: ffffffff8cd286c0 R09: 0000000000000001
R10: ffff88801b5deeb0 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001
 call_timer_fn+0x113/0x700 kernel/time/timer.c:1335
 expire_timers+0x243/0x4e0 kernel/time/timer.c:1375
 __run_timers kernel/time/timer.c:1703 [inline]
 run_timer_softirq+0x21c/0x670 kernel/time/timer.c:1716
 __do_softirq+0x26c/0x9a0 kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:372 [inline]
 irq_exit+0x215/0x260 kernel/softirq.c:412
 exiting_irq arch/x86/include/asm/apic.h:544 [inline]
 smp_apic_timer_interrupt+0x136/0x550 arch/x86/kernel/apic/apic.c:1094
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894
 </IRQ>
RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x4/0x50 kernel/kcov.c:100
Code: fd 6d 88 4c 89 25 dc 4a bf 0b 41 bc f4 ff ff ff e8 20 fa ea ff 48 c7 05 c6 4a bf 0b 00 00 00 00 e9 39 ec ff ff 90 48 8b 34 24 <65> 48 8b 04 25 80 df 01 00 65 8b 15 fc 0f 9d 7e 81 e2 00 01 1f 00
RSP: 0018:ffff88801326fa90 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000002 RBX: 0000000000000000 RCX: ffffffff81a8ede9
RDX: 0000000000000000 RSI: ffffffff81a8edf6 RDI: 0000000000000001
RBP: 000000059eb3afbf R08: ffffffff8cd38790 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff88801326fcbc
R13: 0000000000000005 R14: ffff88801326fc78 R15: ffff8880119f4667
 link_path_walk.part.0+0x496/0x1230 fs/namei.c:2132
 link_path_walk fs/namei.c:2073 [inline]
 path_mountpoint+0xce/0xac0 fs/namei.c:2695
 filename_mountpoint+0x184/0x4f0 fs/namei.c:2718
 ksys_umount+0x156/0x1070 fs/namespace.c:1645
 __do_sys_umount fs/namespace.c:1671 [inline]
 __se_sys_umount fs/namespace.c:1669 [inline]
 __x64_sys_umount+0x50/0x70 fs/namespace.c:1669
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45deb9
Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f5504693c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: ffffffffffffffda RBX: 0000000000038100 RCX: 000000000045deb9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000200001c0
RBP: 000000000118bf58 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c
R13: 00007ffd619a7b4f R14: 00007f55046949c0 R15: 000000000118bf2c

Crashes (16):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/11/04 12:30 linux-4.19.y f5d8eef067ac cba33199 .config console log report info ci2-linux-4-19
2020/11/03 14:10 linux-4.19.y f5d8eef067ac cba33199 .config console log report info ci2-linux-4-19
2020/10/17 08:37 linux-4.19.y a1b977b49b66 6e262c73 .config console log report info ci2-linux-4-19
2020/09/14 09:54 linux-4.19.y a87f96283793 2d3cdd63 .config console log report ci2-linux-4-19
2020/09/08 07:21 linux-4.19.y c37da90efff5 abf9ba4f .config console log report ci2-linux-4-19
2020/08/31 03:42 linux-4.19.y f6d5cb9e2c06 d5a3ae1f .config console log report ci2-linux-4-19
2020/08/04 06:20 linux-4.19.y 13af6c74b14a 96dd3623 .config console log report ci2-linux-4-19
2020/07/03 09:45 linux-4.19.y 399849e4654e f30c14bf .config console log report ci2-linux-4-19
2020/06/28 16:29 linux-4.19.y a39e75458e1c a2cdad9d .config console log report ci2-linux-4-19
2020/05/12 23:14 linux-4.19.y 033c4ea49a4b a44eb8f7 .config console log report ci2-linux-4-19
2020/03/11 04:48 linux-4.19.y 7472c4028e23 35f53e45 .config console log report ci2-linux-4-19
2020/02/28 22:06 linux-4.19.y a083db76118d c88c7b75 .config console log report ci2-linux-4-19
2020/02/21 00:41 linux-4.19.y 4fccc2503536 81230308 .config console log report ci2-linux-4-19
2020/02/17 14:58 linux-4.19.y 9b15f7fae677 72bfa6f2 .config console log report ci2-linux-4-19
2020/02/09 19:06 linux-4.19.y b499cf4b3a90 6ece2ea5 .config console log report ci2-linux-4-19
2020/02/04 10:03 linux-4.19.y 32ee7492f104 93e5e335 .config console log report ci2-linux-4-19
* Struck through repros no longer work on HEAD.