INFO: rcu detected stall in unwind_next_frame

Status: auto-obsoleted due to no activity on 2025/12/01 20:02
Reported-by: syzbot+38257bebbf1a73444807@syzkaller.appspotmail.com
First crash: 340d, last: 340d
▶ ▼ Similar bugs (9)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in unwind_next_frame (2) kernel 1 1 1070d 1070d 0/29 auto-obsoleted due to no activity on 2023/10/24 10:24
linux-6.1 INFO: rcu detected stall in unwind_next_frame (2) 1 1 855d 855d 0/3 auto-obsoleted due to no activity on 2024/07/04 19:31
upstream INFO: rcu detected stall in unwind_next_frame (5) prio:low ext4 1 syz, C error error 58 1d11h 289d 0/29 upstream: reported C repro on 2025/10/14 01:28
linux-6.1 INFO: rcu detected stall in unwind_next_frame (3) 1 2 35d 78d 0/3 upstream: reported on 2026/05/13 02:27
upstream INFO: rcu detected stall in unwind_next_frame (3) kernel 1 1 1003d 1003d 0/29 auto-obsoleted due to no activity on 2024/01/29 09:37
linux-6.1 INFO: rcu detected stall in unwind_next_frame 1 1 1021d 1021d 0/3 auto-obsoleted due to no activity on 2024/01/21 04:23
upstream INFO: rcu detected stall in unwind_next_frame (4) mm 1 7 641d 774d 0/29 auto-obsoleted due to no activity on 2025/01/25 06:35
linux-6.6 INFO: rcu detected stall in unwind_next_frame 1 1 22d 22d 0/2 upstream: reported on 2026/07/08 12:08
upstream INFO: rcu detected stall in unwind_next_frame kernel 1 2 2992d 2995d 8/29 fixed on 2018/07/09 18:05

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-....: (1 ticks this GP) idle=60f/1/0x4000000000000000 softirq=8322/8322 fqs=2100 
	(detected by 1, t=10503 jiffies, g=10585, q=1224)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 3560 Comm: udevd Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:check_preemption_disabled+0x13/0x110 lib/smp_processor_id.c:13
Code: 5b 76 5b c3 00 00 cc 48 c7 c7 e0 92 59 8a 48 c7 c6 20 93 59 8a eb 00 55 41 57 41 56 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 <48> 89 44 24 08 65 8b 05 a9 d7 59 76 65 8b 0d 12 32 5a 76 f7 c1 ff
RSP: 0018:ffffc90000006e68 EFLAGS: 00000082
RAX: 9b99a8b4826fae00 RBX: 0000000000000000 RCX: ffffffff815bf63b
RDX: 0000000000000000 RSI: ffffffff8a599320 RDI: ffffffff8a5992e0
RBP: ffffc90000006fe0 R08: dffffc0000000000 R09: fffffbfff1ad2dd6
R10: fffffbfff1ad2dd6 R11: 1ffffffff1ad2dd5 R12: ffffffff8c11c360
R13: 1ffff92000000de4 R14: 0000000000000000 R15: dffffc0000000000
FS:  00007f8f88061880(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff8356832f8 CR3: 0000000029680000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:331 [inline]
 rcu_is_watching+0x11/0xa0 kernel/rcu/tree.c:1123
 trace_lock_acquire include/trace/events/lock.h:13 [inline]
 lock_acquire+0xcd/0x3f0 kernel/locking/lockdep.c:5594
 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+0x97/0xa30 kernel/events/ring_buffer.c:271
 __perf_event_output kernel/events/core.c:7790 [inline]
 perf_event_output_forward+0x15c/0x280 kernel/events/core.c:7808
 __perf_event_overflow+0x364/0x530 kernel/events/core.c:9501
 perf_tp_event+0x32c/0xb50 kernel/events/core.c:10033
 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10007
 perf_trace_preemptirq_template+0x2be/0x380 include/trace/events/preemptirq.h:14
 trace_irq_enable_rcuidle+0x108/0x180 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+0x84/0x480 kernel/rcu/tree_plugin.h:671
Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 7d 16 9e 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0018:ffffc900000077a0 EFLAGS: 00000206
RAX: 9b99a8b4826fae00 RBX: 1ffff92000000ef8 RCX: 9b99a8b4826fae00
RDX: dffffc0000000000 RSI: ffffffff8a0b15c0 RDI: ffffffff8a599340
RBP: ffffc90000007880 R08: dffffc0000000000 R09: fffffbfff1ff6e39
R10: fffffbfff1ff6e39 R11: 1ffffffff1ff6e38 R12: ffffffff8c120800
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
 rcu_read_unlock include/linux/rcupdate.h:771 [inline]
 ndisc_send_skb+0xdc4/0x14a0 net/ipv6/ndisc.c:521
 addrconf_rs_timer+0x2b8/0x600 net/ipv6/addrconf.c:3957
 call_timer_fn+0x16c/0x530 kernel/time/timer.c:1451
 expire_timers kernel/time/timer.c:1496 [inline]
 __run_timers+0x525/0x7c0 kernel/time/timer.c:1767
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780
 handle_softirqs+0x328/0x820 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x12f/0x220 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:unwind_next_frame+0x8bb/0x1d90 arch/x86/kernel/unwind_orc.c:535
Code: 04 28 84 c0 0f 85 fa 12 00 00 4c 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 14 13 00 00 48 0f bf 02 48 01 c7 48 89 7c 24 08 <4d> 8d 7e 01 43 0f b6 04 2c 84 c0 0f 85 20 0f 00 00 4c 89 fa 48 c1
RSP: 0018:ffffc90002dff8c8 EFLAGS: 00000282
RAX: 0000000000000010 RBX: ffffc90002dff988 RCX: ffffffff8d7ec808
RDX: ffffffff8dede824 RSI: ffffffff8dede806 RDI: ffffc90002dffcf8
RBP: ffffc90002dff9d0 R08: 0000000000000011 R09: 0000000000000000
R10: fffff520005bff3d R11: 1ffff920005bff3b R12: 1ffffffff1bdbd05
R13: dffffc0000000000 R14: ffffffff8dede828 R15: ffffffff8dede825
 arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:46
 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1705 [inline]
 slab_free_freelist_hook+0xea/0x170 mm/slub.c:1731
 slab_free mm/slub.c:3499 [inline]
 kmem_cache_free+0x8f/0x210 mm/slub.c:3515
 file_free fs/file_table.c:55 [inline]
 __fput+0x627/0x930 fs/file_table.c:324
 task_work_run+0x125/0x1a0 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f8f8814f407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffcb4d5ac60 EFLAGS: 00000202 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 00007f8f88061880 RCX: 00007f8f8814f407
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000000000c
RBP: 00007f8f880616e8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000002
R13: 00000000ffffffff R14: ffffffffffffffff R15: 00007ffcb4d5af60
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/23 20:01 linux-5.15.y c79648372d02 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in unwind_next_frame
* Struck through repros no longer work on HEAD.