syzbot


INFO: rcu detected stall in do_idle

Status: upstream: reported C repro on 2025/06/24 01:25
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+1d0ebb5530b0023d4b6b@syzkaller.appspotmail.com
First crash: 205d, last: 4d15h
Bug presence (2)
Date Name Commit Repro Result
2025/08/07 linux-6.6.y (ToT) 3a8ababb8b6a C [report] INFO: rcu detected stall in worker_thread
2025/08/07 upstream (ToT) 6e64f4580381 C Didn't crash
Similar bugs (8)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 BUG: soft lockup in do_idle origin:upstream 1 C error 699 23m 961d 0/3 upstream: reported C repro on 2023/05/29 19:14
android-414 INFO: rcu detected stall in do_idle 1 1 2680d 2680d 0/1 auto-closed as invalid on 2019/03/13 10:31
linux-4.19 INFO: rcu detected stall in do_idle (2) 1 2 1360d 1360d 0/1 auto-closed as invalid on 2022/08/24 07:48
linux-4.19 INFO: rcu detected stall in do_idle 1 1 2218d 2218d 0/1 auto-closed as invalid on 2020/04/18 00:25
linux-4.14 INFO: rcu detected stall in do_idle 1 4 2313d 2319d 0/1 auto-closed as invalid on 2020/01/14 08:59
upstream INFO: rcu detected stall in do_idle x86 1 C done error 3734 2h22m 2651d 0/29 upstream: reported C repro on 2018/10/13 07:31
linux-4.14 INFO: rcu detected stall in do_idle (2) 1 C error 4 1234d 1364d 0/1 upstream: reported C repro on 2022/04/22 10:09
linux-6.1 BUG: soft lockup in do_idle origin:upstream 1 C error 55 9h59m 950d 0/3 upstream: reported C repro on 2023/06/10 08:51
Fix bisection attempts (1)
Created Duration User Patch Repo Result
2025/08/14 09:08 2h09m fix candidate upstream OK (0) job log

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...0: (1 GPs behind) idle=d96c/0/0x1 softirq=11855/11856 fqs=2100
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:        0          0            0
rcu: 	cputime:        0          0            0   ==> 52550(ms)
rcu: 	(detected by 1, t=10506 jiffies, g=8761, q=282 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:rcu_dynticks_curr_cpu_in_eqs include/linux/context_tracking.h:122 [inline]
RIP: 0010:rcu_is_watching+0x35/0xb0 kernel/rcu/tree.c:700
Code: 05 f8 1b 94 7e e8 8b f2 f7 08 89 c3 83 f8 08 73 60 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd 30 8a 7c 8c 4c 89 f0 48 c1 e8 03 <42> 80 3c 38 00 74 08 4c 89 f7 e8 ac 64 6d 00 48 c7 c3 28 6b 03 00
RSP: 0018:ffffc90000007ac0 EFLAGS: 00000802
RAX: 1ffffffff18f9146 RBX: 0000000000000000 RCX: dc62335456c30700
RDX: 0000000000000000 RSI: ffffffff8afc6f60 RDI: ffffffff8afc6f20
RBP: ffffc90000007be8 R08: ffffffff8e4a212f R09: 1ffffffff1c94425
R10: dffffc0000000000 R11: fffffbfff1c94426 R12: 1ffff92000000f68
R13: ffffffff9715fb20 R14: ffffffff8c7c8a30 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000003c80 CR3: 000000007be70000 CR4: 00000000003506f0
Call Trace:
 <IRQ>
 trace_lock_acquire include/trace/events/lock.h:24 [inline]
 lock_acquire+0xcb/0x410 kernel/locking/lockdep.c:5725
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xa8/0xf0 kernel/locking/spinlock.c:162
 debug_object_activate+0x6c/0x4b0 lib/debugobjects.c:709
 debug_hrtimer_activate kernel/time/hrtimer.c:450 [inline]
 debug_activate kernel/time/hrtimer.c:505 [inline]
 enqueue_hrtimer+0x30/0x370 kernel/time/hrtimer.c:1108
 __run_hrtimer kernel/time/hrtimer.c:1767 [inline]
 __hrtimer_run_queues+0x637/0xc40 kernel/time/hrtimer.c:1814
 hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1876
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline]
 __sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1088
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:148
Code: cc cc cc cc cc cc cc f3 0f 1e fa 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 66 90 0f 00 2d 23 bb 40 00 f3 0f 1e fa fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc 66 0f 1f 00 55 41 57 41 56
RSP: 0018:ffffffff8ca07d80 EFLAGS: 000002c2
RAX: dc62335456c30700 RBX: ffffffff8161881b RCX: dc62335456c30700
RDX: 0000000000000001 RSI: ffffffff8aaabce0 RDI: ffffffff8afc6f80
RBP: ffffffff8ca07eb8 R08: ffff8880b8e36b2b R09: 1ffff110171c6d65
R10: dffffc0000000000 R11: ffffed10171c6d66 R12: ffffffff8e4a2128
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1952688
 arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:753
 default_idle_call+0x6c/0xa0 kernel/sched/idle.c:97
 cpuidle_idle_call kernel/sched/idle.c:170 [inline]
 do_idle+0x1eb/0x510 kernel/sched/idle.c:282
 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:380
 rest_init+0x2e2/0x300 init/main.c:744
 arch_call_rest_init+0xe/0x10 init/main.c:841
 start_kernel+0x459/0x4e0 init/main.c:1086
 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:555
 x86_64_start_kernel+0x60/0x60 arch/x86/kernel/head64.c:536
 secondary_startup_64_no_verify+0x179/0x17b
 </TASK>

Crashes (39):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/10 18:00 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in do_idle
2026/01/01 11:25 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in do_idle
2025/11/01 01:22 linux-6.6.y e5bbb12db2c7 2c50b6a9 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in do_idle
2025/08/06 14:36 linux-6.6.y 3a8ababb8b6a ffe1dd46 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in do_idle
2025/08/15 01:43 linux-6.6.y 3a8ababb8b6a 5d8c2ac2 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf BUG: soft lockup in do_idle
2025/07/12 22:20 linux-6.6.y 59a2de10b81a 3cda49cf .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf BUG: soft lockup in do_idle
2025/09/09 11:14 linux-6.6.y 355bd0b51d2f d291dd2d .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in do_idle
2026/01/10 20:23 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in do_idle
2026/01/10 00:38 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in do_idle
2026/01/09 22:00 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in do_idle
2026/01/03 11:55 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in do_idle
2026/01/02 03:35 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in do_idle
2025/12/29 04:11 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in do_idle
2025/12/28 03:42 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in do_idle
2025/12/25 08:08 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in do_idle
2025/12/16 13:32 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in do_idle
2025/12/11 07:54 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in do_idle
2025/12/02 00:40 linux-6.6.y 4791134e4aeb d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in do_idle
2025/11/30 22:21 linux-6.6.y 1e89a1be4fe9 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in do_idle
2025/11/24 23:31 linux-6.6.y 1e89a1be4fe9 bf6fe8fe .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in do_idle
2025/11/22 02:39 linux-6.6.y 0a805b6ea8cd 4fb8ef37 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in do_idle
2025/11/21 00:34 linux-6.6.y 0a805b6ea8cd 2cc4c24a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in do_idle
2025/11/12 20:34 linux-6.6.y 0a805b6ea8cd 07e030de .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in do_idle
2025/11/07 08:06 linux-6.6.y 0a805b6ea8cd 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in do_idle
2025/11/04 03:00 linux-6.6.y 0a805b6ea8cd 686bf657 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in do_idle
2025/10/31 00:57 linux-6.6.y e5bbb12db2c7 2c50b6a9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in do_idle
2025/10/01 19:47 linux-6.6.y 147338df3487 a1859138 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in do_idle
2025/09/30 10:52 linux-6.6.y 147338df3487 86341da6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in do_idle
2025/09/06 01:49 linux-6.6.y 355bd0b51d2f d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in do_idle
2025/09/03 17:56 linux-6.6.y cc1a1c5b404a 96a211bc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in do_idle
2025/09/02 20:01 linux-6.6.y cc1a1c5b404a 96a211bc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in do_idle
2025/08/28 11:58 linux-6.6.y bb9c90ab9c5a e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in do_idle
2025/08/15 23:25 linux-6.6.y bb9c90ab9c5a 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in do_idle
2025/08/12 14:01 linux-6.6.y 3a8ababb8b6a c06e8995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in do_idle
2025/08/06 05:40 linux-6.6.y 3a8ababb8b6a ffe1dd46 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in do_idle
2025/07/22 07:11 linux-6.6.y d96eb99e2f0e 1555463b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in do_idle
2025/07/22 06:50 linux-6.6.y d96eb99e2f0e 1555463b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in do_idle
2025/07/01 04:37 linux-6.6.y 3f5b4c104b7d 6e83b42d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in do_idle
2025/06/24 01:24 linux-6.6.y 6282921b6825 e2f27c35 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in do_idle
* Struck through repros no longer work on HEAD.