INFO: rcu detected stall in task_work_run (2)

Status: auto-obsoleted due to no activity on 2025/03/24 21:44
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+8760ad4051ab603b59ab@syzkaller.appspotmail.com
First crash: 599d, last: 599d
Fix bisection: failed (error log, bisect log)
  
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2024/12/02 linux-5.15.y (ToT) 0a51d2d4527b syz [report] INFO: rcu detected stall in corrupted
2024/12/02 upstream (ToT) e70140ba0d2b syz Didn't crash
▶ ▼ Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 INFO: rcu detected stall in task_work_run (3) origin:lts-only 1 syz error 7 136d 313d 0/3 upstream: reported syz repro on 2025/09/13 23:38
linux-6.1 INFO: rcu detected stall in task_work_run origin:lts-only 1 C error 3 26d 323d 0/3 upstream: reported C repro on 2025/09/04 00:43
linux-5.15 INFO: rcu detected stall in task_work_run 1 1 850d 850d 0/3 auto-obsoleted due to no activity on 2024/07/04 00:01
upstream INFO: rcu detected stall in task_work_run kernel 1 2 1079d 1129d 0/29 auto-obsoleted due to no activity on 2023/11/07 12:15
▶ ▼ Last patch testing requests (1)
Created Duration User Patch Repo Result
2025/03/24 21:28 15m retest repro linux-5.15.y OK log

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-....: (1 ticks this GP) idle=5c1/1/0x4000000000000002 softirq=17384/17386 fqs=5249 
	(detected by 1, t=10502 jiffies, g=22529, q=230)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 5463 Comm: syz.0.1122 Not tainted 5.15.173-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:kasan_check_range+0x1ab/0x290 mm/kasan/generic.c:189
Code: e9 4c 89 d5 48 8d 5d 07 48 85 ed 48 0f 49 dd 48 83 e3 f8 48 29 dd 74 12 41 80 39 00 0f 85 a2 00 00 00 49 ff c1 48 ff cd 75 ee <5b> 41 5e 41 5f 5d c3 45 84 f6 75 61 41 f7 c6 00 ff 00 00 75 5d 41
RSP: 0018:ffffc90000006f58 EFLAGS: 00000056
RAX: 0000000000000001 RBX: 1ffffffff2131020 RCX: ffffffff8162ca83
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90988100
RBP: 0000000000000001 R08: dffffc0000000000 R09: fffffbfff2131021
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000
R13: ffff8880283b28d0 R14: fffffbfff2131021 R15: ffff8880283b2902
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2e05ffff CR3: 000000000c88e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 instrument_atomic_read include/linux/instrumented.h:71 [inline]
 test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline]
 hlock_class kernel/locking/lockdep.c:197 [inline]
 check_wait_context kernel/locking/lockdep.c:4711 [inline]
 __lock_acquire+0x7a3/0x1ff0 kernel/locking/lockdep.c:4962
 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312
 rcu_read_lock include/linux/rcupdate.h:739 [inline]
 __perf_output_begin kernel/events/ring_buffer.c:163 [inline]
 perf_output_begin_forward+0xb1/0xac0 kernel/events/ring_buffer.c:271
 __perf_event_output kernel/events/core.c:7779 [inline]
 perf_event_output_forward+0x1c8/0x310 kernel/events/core.c:7797
 __perf_event_overflow+0x35d/0x530 kernel/events/core.c:9490
 perf_swevent_overflow kernel/events/core.c:9566 [inline]
 perf_swevent_event+0x4c5/0x550 kernel/events/core.c:9604
 perf_tp_event+0x363/0xc40 kernel/events/core.c:10022
 perf_trace_run_bpf_submit+0xf7/0x1d0 kernel/events/core.c:9996
 perf_trace_preemptirq_template+0x31d/0x430 include/trace/events/preemptirq.h:14
 trace_irq_enable_rcuidle+0x10e/0x190 include/trace/events/preemptirq.h:40
 trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713
RIP: 0010:rcu_read_unlock_special+0x84/0x520 kernel/rcu/tree_plugin.h:671
Code: f1 f1 f1 00 f2 f2 f2 49 89 04 17 66 41 c7 44 17 09 f3 f3 41 c6 44 17 0b f3 65 44 8b 25 bd 92 96 7e 41 f7 c4 00 00 f0 00 74 45 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 3a 00 00 00 00 66 42 c7 44 3a
RSP: 0018:ffffc900000079e0 EFLAGS: 00000206
RAX: cd9b7fad20a1e100 RBX: 1ffff92000000f44 RCX: ffffffff96a8ef03
RDX: dffffc0000000000 RSI: ffffffff8aab2a80 RDI: ffffffff8af9ed00
RBP: ffffc90000007ab8 R08: ffffffff8186f3c8 R09: ffffed10171c765a
R10: 0000000000000000 R11: dffffc0000000001 R12: ffffffff8cb23c00
R13: ffff8880283b2218 R14: ffffc90000007a20 R15: 1ffff92000000f40
 __rcu_read_unlock+0x92/0x100 kernel/rcu/tree_plugin.h:422
 rcu_read_unlock include/linux/rcupdate.h:771 [inline]
 process_backlog+0x3e2/0x7f0 net/core/dev.c:6485
 __napi_poll+0xc7/0x440 net/core/dev.c:7043
 napi_poll net/core/dev.c:7110 [inline]
 net_rx_action+0x617/0xda0 net/core/dev.c:7200
 handle_softirqs+0x3a7/0x930 kernel/softirq.c:558
 __do_softirq kernel/softirq.c:592 [inline]
 invoke_softirq kernel/softirq.c:432 [inline]
 __irq_exit_rcu+0x157/0x240 kernel/softirq.c:641
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:653
 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:__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: 31 61 f6 ff 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 1e a5 1a f7 48 89 df e8 76 f9 1b f7 e8 31 b4 3e f7 fb bf 01 00 00 00 <e8> d6 3e 0f f7 65 8b 05 f7 31 ba 75 85 c0 74 02 5b c3 e8 c4 4e b8
RSP: 0018:ffffc900059b7d20 EFLAGS: 00000282
RAX: cd9b7fad20a1e100 RBX: ffff8880283b27d0 RCX: ffffffff96a8ef03
RDX: dffffc0000000000 RSI: ffffffff8aab2a80 RDI: 0000000000000001
RBP: ffff8880283b27d0 R08: ffffffff8186f3c8 R09: ffffed10171c765a
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff8880283b2738
R13: dffffc0000000000 R14: 1ffff110050764e7 R15: 0000000000000000
 task_work_run+0xf3/0x1a0 kernel/task_work.c:184
 exit_task_work include/linux/task_work.h:33 [inline]
 do_exit+0x6a3/0x2480 kernel/exit.c:874
 do_group_exit+0x144/0x310 kernel/exit.c:996
 __do_sys_exit_group kernel/exit.c:1007 [inline]
 __se_sys_exit_group kernel/exit.c:1005 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1005
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f7cd5645849
Code: Unable to access opcode bytes at RIP 0x7f7cd564581f.
RSP: 002b:00007ffe4c553b58 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7cd5645849
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffe4c553bac R08: 00007ffe4c553c3f R09: 00000000000567ad
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000032
R13: 00000000000567ad R14: 000000000005678d R15: 00007ffe4c553c00
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/12/01 21:30 linux-5.15.y 0a51d2d4527b 68914665 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in task_work_run
* Struck through repros no longer work on HEAD.