INFO: rcu detected stall in call_timer_fn (3)

Status: upstream: reported on 2026/07/10 22:14
Reported-by: syzbot+ebff3a27d86a72115648@syzkaller.appspotmail.com
First crash: 24d, last: 11d
▶ ▼ Similar bugs (15)
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 734d 777d 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 660d 731d 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 2098d 2372d 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 syz, C 9 389d 523d 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 2161d 2161d 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 18d 318d 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 1658d 2514d 0/29 closed as invalid on 2022/02/08 10:46
upstream INFO: rcu detected stall in call_timer_fn bpf net 1 2 2851d 2864d 0/29 closed as dup on 2019/01/02 16:26
linux-4.19 INFO: rcu detected stall in call_timer_fn 1 1 2512d 2512d 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 155d 175d 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 2285d 2405d 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 915d 915d 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 1397d 1412d 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 syz, C error 31 1248d 1851d 0/1 upstream: reported C repro on 2021/07/10 02:48
upstream BUG: soft lockup in call_timer_fn (2) trace 1 1 660d 656d 0/29 auto-obsoleted due to no activity on 2025/01/10 05:15

Sample crash report:
rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 0-.... } 2655 jiffies s: 222665 root: 0x1/.
rcu: blocking rcu_node structures (internal RCU debug):
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 32268 Comm: syz.1.8430 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:check_region_inline mm/kasan/generic.c:-1 [inline]
RIP: 0010:kasan_check_range+0xc/0x290 mm/kasan/generic.c:189
Code: c0 c3 0f 0b b8 ea ff ff ff c3 0f 0b b8 ea ff ff ff c3 00 00 cc cc 00 00 cc cc 00 00 cc cc b0 01 48 85 f6 0f 84 ac 01 00 00 55 <41> 57 41 56 41 54 53 49 89 f8 49 01 f0 0f 82 0e 02 00 00 49 89 f8
RSP: 0018:ffffc90000007390 EFLAGS: 00000002
RAX: 1ffff11002e8e801 RBX: 000000000000030c RCX: ffffffff81845152
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff8880174c2008
RBP: ffff888017478810 R08: ffff8880174c200f R09: 1ffff11002e98401
R10: dffffc0000000000 R11: ffffed1002e98402 R12: 1ffff11002e8f11f
R13: ffff8880174788a0 R14: dffffc0000000000 R15: ffff8880174c2008
FS:  00007f35572996c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff1efdced58 CR3: 000000013febb000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000008d24
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 instrument_atomic_read include/linux/instrumented.h:72 [inline]
 atomic_long_read include/linux/atomic/atomic-instrumented.h:1265 [inline]
 rb_page_commit kernel/trace/ring_buffer.c:359 [inline]
 rb_commit_index kernel/trace/ring_buffer.c:2461 [inline]
 rb_set_commit_to_write kernel/trace/ring_buffer.c:3103 [inline]
 rb_end_commit kernel/trace/ring_buffer.c:3141 [inline]
 rb_commit+0x532/0x750 kernel/trace/ring_buffer.c:3177
 ring_buffer_unlock_commit+0x79/0x5f0 kernel/trace/ring_buffer.c:3384
 __buffer_unlock_commit kernel/trace/trace.c:1007 [inline]
 trace_buffer_unlock_commit_regs+0x59/0x600 kernel/trace/trace.c:2971
 trace_event_buffer_commit+0x21f/0x780 kernel/trace/trace.c:2946
 do_trace_event_raw_event_bpf_trace_printk kernel/trace/bpf_trace.h:11 [inline]
 trace_event_raw_event_bpf_trace_printk+0x163/0x230 kernel/trace/bpf_trace.h:11
 trace_bpf_trace_printk+0x199/0x220 kernel/trace/bpf_trace.h:11
 ____bpf_trace_printk kernel/trace/bpf_trace.c:391 [inline]
 bpf_trace_printk+0x13e/0x1c0 kernel/trace/bpf_trace.c:374
 bpf_prog_b1bcf1c1da0a8648+0x38/0x3c
 bpf_dispatcher_nop_func include/linux/bpf.h:1012 [inline]
 __bpf_prog_run include/linux/filter.h:607 [inline]
 bpf_prog_run include/linux/filter.h:614 [inline]
 bpf_prog_run_array include/linux/bpf.h:1668 [inline]
 trace_call_bpf+0x322/0x6b0 kernel/trace/bpf_trace.c:135
 perf_trace_run_bpf_submit+0x79/0x1c0 kernel/events/core.c:10027
 perf_trace_preemptirq_template+0x268/0x320 include/trace/events/preemptirq.h:14
 trace_irq_disable include/trace/events/preemptirq.h:36 [inline]
 trace_hardirqs_off_finish+0x13f/0x180 kernel/trace/trace_preemptirq.c:67
 irqentry_enter+0x33/0x50 kernel/entry/common.c:382
 sysvec_apic_timer_interrupt+0xa/0xc0 arch/x86/kernel/apic/apic.c:1118
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xbc/0x120 kernel/locking/spinlock.c:194
Code: c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 41 c6 04 07 f8 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 4f 57 1e f7 65 8b 05 50 08 c8 75 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc90000007ae0 EFLAGS: 00000206
RAX: dffffc0000000004 RBX: 0000000000000a06 RCX: 090115137d2fe600
RDX: dffffc0000000000 RSI: ffffffff8a8c17a0 RDI: 0000000000000001
RBP: ffffc90000007b70 R08: ffffffff90b102bf R09: 1ffffffff2162057
R10: dffffc0000000000 R11: fffffbfff2162058 R12: dffffc0000000000
R13: 1ffff92000000f74 R14: ffffffff8dae5aa0 R15: 1ffff92000000f5c
 call_timer_fn+0x1ac/0x670 kernel/time/timer.c:1701
 expire_timers kernel/time/timer.c:1752 [inline]
 __run_timers+0x56c/0x810 kernel/time/timer.c:2023
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:2036
 handle_softirqs+0x291/0x910 kernel/softirq.c:596
 __do_softirq kernel/softirq.c:630 [inline]
 invoke_softirq kernel/softirq.c:470 [inline]
 __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:679
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691
 instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline]
 sysvec_irq_work+0x9d/0xc0 arch/x86/kernel/irq_work.c:17
 </IRQ>
 <TASK>
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:728
RIP: 0010:preempt_schedule_irq+0xb6/0x160 kernel/sched/core.c:6874
Code: 00 00 43 c6 44 37 04 f8 74 0b 0f 0b 48 f7 03 08 00 00 00 74 7f bf 01 00 00 00 e8 b5 cf 1f f7 e8 b0 99 4f f7 fb bf 01 00 00 00 <e8> 25 ba ff ff 43 c6 44 37 08 00 48 c7 44 24 40 00 00 00 00 9c 8f
RSP: 0018:ffffc9000c6c75e0 EFLAGS: 00000282
RAX: 090115137d2fe600 RBX: 0000000000000000 RCX: 090115137d2fe600
RDX: dffffc0000000000 RSI: ffffffff8a8c17a0 RDI: 0000000000000001
RBP: ffffc9000c6c7680 R08: ffffffff8fa25008 R09: ffffffff8fa25018
R10: ffffffff8fa25010 R11: ffffffff8fa25003 R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff920018d8ebc
 irqentry_exit+0x63/0x70 kernel/entry/common.c:439
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:memcg_account_kmem+0x187/0x1c0 mm/memcontrol.c:-1
Code: 80 00 00 00 75 1f 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 69 8a 55 08 41 f7 c6 00 02 00 00 75 b2 eb b1 e8 49 8a 55 08 <48> 81 44 24 18 c0 02 00 00 44 89 f8 45 85 ff 7e 0e 89 c6 48 8b 7c
RSP: 0018:ffffc9000c6c7740 EFLAGS: 00000206
RAX: 090115137d2fe600 RBX: 0000000000000001 RCX: 090115137d2fe600
RDX: dffffc0000000000 RSI: ffffffff8a8c17a0 RDI: ffffffff8adf42e0
RBP: ffffc9000c6c7810 R08: ffff8880b8e3580b R09: 1ffff110171c6b01
R10: dffffc0000000000 R11: ffffed10171c6b02 R12: dffffc0000000000
R13: 1ffff920018d8eec R14: 0000000000000a02 R15: 0000000000000001
 obj_cgroup_charge_pages mm/memcontrol.c:3103 [inline]
 obj_cgroup_charge+0x37c/0x620 mm/memcontrol.c:3390
 memcg_slab_pre_alloc_hook mm/slab.h:501 [inline]
 slab_pre_alloc_hook+0x2e2/0x300 mm/slab.h:715
 slab_alloc_node mm/slub.c:3279 [inline]
 slab_alloc mm/slub.c:3367 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3374 [inline]
 kmem_cache_alloc+0x56/0x2f0 mm/slub.c:3383
 kmem_cache_zalloc include/linux/slab.h:689 [inline]
 __alloc_file+0x25/0x230 fs/file_table.c:138
 alloc_empty_file+0x90/0x180 fs/file_table.c:187
 alloc_file+0x5b/0x5f0 fs/file_table.c:229
 alloc_file_pseudo+0x180/0x200 fs/file_table.c:272
 __anon_inode_getfile fs/anon_inodes.c:122 [inline]
 __anon_inode_getfd fs/anon_inodes.c:207 [inline]
 anon_inode_getfd+0xc6/0x1b0 fs/anon_inodes.c:242
 bpf_prog_load+0x114d/0x1530 kernel/bpf/syscall.c:2681
 __sys_bpf+0x5b8/0x780 kernel/bpf/syscall.c:5031
 __do_sys_bpf kernel/bpf/syscall.c:5135 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5133 [inline]
 __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5133
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f355639de99
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:00007f3557299028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f3556625fa0 RCX: 00007f355639de99
RDX: 0000000000000094 RSI: 00002000000000c0 RDI: 0000000000000005
RBP: 00007f3556433eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3556626038 R14: 00007f3556625fa0 R15: 00007ffd96150a08
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/07/23 21:01 linux-6.1.y 090666d3cc90 71a13572 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in call_timer_fn
2026/07/10 22:14 linux-6.1.y 090666d3cc90 99e64375 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in call_timer_fn
* Struck through repros no longer work on HEAD.