syzbot


INFO: rcu detected stall in clock_nanosleep

Status: upstream: reported on 2025/12/21 12:05
Reported-by: syzbot+7f2ffeff791dbe94e0a7@syzkaller.appspotmail.com
First crash: 11h29m, last: 11h29m
Similar bugs (10)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in sys_clock_nanosleep (5) kernel 1 C error done 102 56d 857d 0/29 upstream: reported C repro on 2023/08/17 09:25
linux-5.15 INFO: rcu detected stall in sys_clock_nanosleep (3) 1 6 70d 333d 0/3 upstream: reported on 2025/01/22 19:59
linux-5.15 INFO: rcu detected stall in sys_clock_nanosleep 1 1 832d 832d 0/3 auto-obsoleted due to no activity on 2023/12/20 18:13
linux-6.1 INFO: rcu detected stall in sys_clock_nanosleep (2) 1 4 556d 711d 0/3 auto-obsoleted due to no activity on 2024/09/21 09:26
upstream INFO: rcu detected stall in sys_clock_nanosleep (4) kernel 1 6 1180d 1301d 0/29 auto-obsoleted due to no activity on 2022/12/31 21:43
upstream INFO: rcu detected stall in sys_clock_nanosleep (3) kernel 1 3 1478d 1487d 0/29 closed as invalid on 2022/02/08 10:00
upstream INFO: rcu detected stall in sys_clock_nanosleep kernel 1 1 1733d 1733d 0/29 auto-closed as invalid on 2021/06/22 18:23
linux-6.1 INFO: rcu detected stall in sys_clock_nanosleep 1 1 1008d 1008d 0/3 auto-obsoleted due to no activity on 2023/07/17 12:13
upstream INFO: rcu detected stall in sys_clock_nanosleep (2) kernel 1 1 1611d 1611d 0/29 auto-closed as invalid on 2021/10/22 22:53
linux-5.15 INFO: rcu detected stall in sys_clock_nanosleep (2) 1 2 635d 708d 0/3 auto-obsoleted due to no activity on 2024/07/04 20:17

Sample crash report:
rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-.... } 2636 jiffies s: 121941 root: 0x2/.
rcu: blocking rcu_node structures (internal RCU debug):
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 17450 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:bpf_prog_abe3471d98b428a0+0x0/0x17
Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 40 00 00 00 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc <0f> 1f 44 00 00 66 90 55 48 89 e5 e8 bc 32 97 e1 48 85 c0 77 00 c9
RSP: 0018:ffffc900001e0778 EFLAGS: 00000046
RAX: 1ffff920009be206 RBX: ffffc90004df1000 RCX: dffffc0000000000
RDX: 1ffffffff1efba08 RSI: ffffc90004df1048 RDI: ffffe8ffffdfe000
RBP: ffffc900001e0878 R08: ffffffff8f7dd048 R09: ffffffff8f7dd058
R10: ffffffff8f7dd050 R11: ffffffff8f7dd043 R12: ffffffff8c97d7a0
R13: ffff88807df38b18 R14: ffff88807df38b28 R15: 0000000000000001
FS:  000055556d99b500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6e75f156c0 CR3: 00000000293c9000 CR4: 00000000003506e0
DR0: 0000200000000300 DR1: 0000200000000300 DR2: 0000200000000300
DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 perf_trace_run_bpf_submit+0x79/0x1c0 kernel/events/core.c:9997
 perf_trace_preemptirq_template+0x287/0x330 include/trace/events/preemptirq.h:14
 trace_irq_enable_rcuidle+0xd3/0x140 include/trace/events/preemptirq.h:40
 trace_hardirqs_on+0x24/0x40 kernel/trace/trace_preemptirq.c:44
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:728
RIP: 0010:rcu_read_unlock_special+0x84/0x500 kernel/rcu/tree_plugin.h:685
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 fd 86 96 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0018:ffffc900001e0aa0 EFLAGS: 00000206
RAX: 8e54a3b7919e7300 RBX: 1ffff9200003c15c RCX: 8e54a3b7919e7300
RDX: dffffc0000000000 RSI: ffffffff8a6c0600 RDI: ffffffff8abef920
RBP: ffffc900001e0b90 R08: dffffc0000000000 R09: ffffed10171e6afa
R10: ffffed10171e6afa R11: 1ffff110171e6af9 R12: 0000000000000246
R13: dffffc0000000000 R14: ffff8880b8f3b900 R15: 0000000000000002
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426
 rcu_read_unlock include/linux/rcupdate.h:823 [inline]
 ieee80211_iterate_active_interfaces_atomic+0x156/0x170 net/mac80211/util.c:826
 mac80211_hwsim_beacon+0xb7/0x1b0 drivers/net/wireless/mac80211_hwsim.c:2147
 __run_hrtimer kernel/time/hrtimer.c:1747 [inline]
 __hrtimer_run_queues+0x554/0xd60 kernel/time/hrtimer.c:1811
 hrtimer_run_softirq+0x183/0x2a0 kernel/time/hrtimer.c:1828
 handle_softirqs+0x2a1/0x920 kernel/softirq.c:596
 __do_softirq kernel/softirq.c:630 [inline]
 invoke_softirq kernel/softirq.c:470 [inline]
 __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:679
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:finish_task_switch+0x26a/0x8f0 kernel/sched/core.c:5123
Code: 0f 84 3b 01 00 00 48 85 db 0f 85 5a 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 c0 f7 c1 08 e8 eb b6 2e 00 fb 4c 8b 65 c0 <49> 8d bc 24 f8 15 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0018:ffffc900056cfa18 EFLAGS: 00000286
RAX: 8e54a3b7919e7300 RBX: 0000000000000000 RCX: 8e54a3b7919e7300
RDX: dffffc0000000000 RSI: ffffffff8a6c0600 RDI: ffffffff8abef920
RBP: ffffc900056cfa70 R08: dffffc0000000000 R09: ffffed10171e6afa
R10: ffffed10171e6afa R11: 1ffff110171e6af9 R12: ffff88802b6d9dc0
R13: dffffc0000000000 R14: ffff888075db8000 R15: ffff8880b8f3b590
 context_switch kernel/sched/core.c:5247 [inline]
 __schedule+0x10f4/0x40b0 kernel/sched/core.c:6561
 schedule+0xb9/0x180 kernel/sched/core.c:6637
 do_nanosleep+0x1a9/0x5f0 kernel/time/hrtimer.c:2088
 hrtimer_nanosleep+0x15b/0x340 kernel/time/hrtimer.c:2136
 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1314 [inline]
 __se_sys_clock_nanosleep+0x2e6/0x370 kernel/time/posix-timers.c:1291
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f21a59c2005
Code: 24 0c 89 3c 24 48 89 4c 24 18 e8 f6 54 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 8b 74 24 0c 8b 3c 24 b8 e6 00 00 00 0f 05 <44> 89 c7 48 89 04 24 e8 4f 55 ff ff 48 8b 04 24 48 83 c4 28 f7 d8
RSP: 002b:00007fffa84069c0 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 0000000000000201 RCX: 00007f21a59c2005
RDX: 00007fffa8406a00 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fffa8406a6c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000001388
R13: 00000000000927c0 R14: 00000000000f8b5b R15: 00007fffa8406ac0
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/12/21 12:04 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in clock_nanosleep
* Struck through repros no longer work on HEAD.