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INFO: rcu detected stall in sys_clock_settime

Status: upstream: reported on 2023/07/13 03:09
Reported-by: syzbot+b9b138957d968392c98d@syzkaller.appspotmail.com
First crash: 848d, last: 36d
▶ ▼ Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 INFO: rcu detected stall in sys_clock_settime origin:lts-only 1 C done 46 2d13h 941d 0/3 upstream: reported C repro on 2023/04/11 17:25
upstream INFO: rcu detected stall in sys_clock_settime kernel 1 C done inconclusive 494 6d14h 1944d 0/29 upstream: reported C repro on 2020/07/12 17:54

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...0: (1 GPs behind) idle=3f5/1/0x4000000000000000 softirq=31730/31731 fqs=617 
	(detected by 0, t=10502 jiffies, g=42385, q=174)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 10569 Comm: syz.1.1278 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:lock_release+0x6/0x870 kernel/locking/lockdep.c:5631
Code: c1 03 38 c1 0f 8c c1 f8 ff ff 48 89 df e8 a2 b8 5f 00 e9 b4 f8 ff ff bb 2f 00 00 00 e9 ca f8 ff ff 0f 1f 00 55 48 89 e5 41 57 <41> 56 41 55 41 54 53 48 83 e4 e0 48 81 ec e0 00 00 00 48 89 74 24
RSP: 0018:ffffc90000dd0c68 EFLAGS: 00000006
RAX: ffffffff88093d9a RBX: 0000000000000001 RCX: ffff888029730000
RDX: 0000000000010000 RSI: ffffffff88093d95 RDI: ffffffff8c11c660
RBP: ffffc90000dd0c70 R08: dffffc0000000000 R09: ffffed100c3e3f32
R10: ffffed100c3e3f32 R11: 1ffff1100c3e3f31 R12: ffff888061f1fae8
R13: dffffc0000000000 R14: ffff888061f1f800 R15: 18778342f4000000
FS:  00007f98e49976c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000061160000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 rcu_read_unlock include/linux/rcupdate.h:772 [inline]
 advance_sched+0x7d0/0x940 net/sched/sch_taprio.c:771
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x53d/0xc40 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0x9b/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_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa5/0x100 kernel/locking/spinlock.c:194
Code: 74 05 e8 ae 4b cb f7 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 36 d5 9e f7 65 8b 05 17 d3 4f 76 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc90003b17b80 EFLAGS: 00000206
RAX: 947240619a398100 RBX: 0000000000000a02 RCX: 947240619a398100
RDX: dffffc0000000000 RSI: ffffffff8a0b1820 RDI: 0000000000000001
RBP: ffffc90003b17c10 R08: dffffc0000000000 R09: fffffbfff1ff7a19
R10: fffffbfff1ff7a19 R11: 1ffffffff1ff7a18 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff8880b902a240 R15: 1ffff92000762f70
 clock_was_set+0x642/0x840 kernel/time/hrtimer.c:955
 do_settimeofday64+0x575/0x720 kernel/time/timekeeping.c:1328
 __do_sys_clock_settime kernel/time/posix-timers.c:1125 [inline]
 __se_sys_clock_settime kernel/time/posix-timers.c:1113 [inline]
 __x64_sys_clock_settime+0x223/0x270 kernel/time/posix-timers.c:1113
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f98e6771ec9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f98e4997038 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3
RAX: ffffffffffffffda RBX: 00007f98e69c9180 RCX: 00007f98e6771ec9
RDX: 0000000000000000 RSI: 0000200000003c80 RDI: 0000000000000000
RBP: 00007f98e67f4f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f98e69c9218 R14: 00007f98e69c9180 R15: 00007fffff0d16f8
 </TASK>
rcu: rcu_preempt kthread starved for 960 jiffies! g42385 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:27464 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11bb/0x4390 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
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 08/18/2025
Call Trace:
 <IRQ>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
 rcu_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487
 print_other_cpu_stall+0x10c8/0x1220 kernel/rcu/tree_stall.h:592
 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
 rcu_pending kernel/rcu/tree.c:3936 [inline]
 rcu_sched_clock_irq+0x831/0x1110 kernel/rcu/tree.c:2619
 update_process_times+0x193/0x200 kernel/time/timer.c:1818
 tick_sched_handle kernel/time/tick-sched.c:254 [inline]
 tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x4fe/0xc40 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0x9b/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:default_idle+0xb/0x10 arch/x86/kernel/process.c:730
Code: bf 48 89 df e8 26 b4 09 f8 eb b5 e8 df af f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 00 cc 66 90 0f 00 2d 67 43 53 00 fb f4 <c3> 0f 1f 40 00 41 57 41 56 53 49 be 00 00 00 00 00 fc ff df 65 48
RSP: 0018:ffffffff8be07dc8 EFLAGS: 000002c6
RAX: 468168411ec56100 RBX: ffffffff8bebc3c0 RCX: 468168411ec56100
RDX: 0000000000000001 RSI: ffffffff8a0b1820 RDI: ffffffff8a59a4c0
RBP: ffffffff8be07ef8 R08: dffffc0000000000 R09: ffffed1017207662
R10: ffffed1017207662 R11: 1ffff11017207661 R12: ffffffff8d6995a8
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff17d7878
 default_idle_call+0x81/0xc0 kernel/sched/idle.c:112
 cpuidle_idle_call kernel/sched/idle.c:194 [inline]
 do_idle+0x21b/0x5b0 kernel/sched/idle.c:306
 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:403
 start_kernel+0x486/0x530 init/main.c:1140
 secondary_startup_64_no_verify+0xb1/0xbb
 </TASK>

Crashes (39):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/10/02 20:38 linux-5.15.y 29e53a5b1c4f 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2025/09/16 07:52 linux-5.15.y 43bb85222e53 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2025/08/08 18:45 linux-5.15.y c79648372d02 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2025/07/21 15:39 linux-5.15.y c79648372d02 56d87229 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2025/06/26 20:47 linux-5.15.y 1c700860e8bc 803ce19b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2025/05/04 19:55 linux-5.15.y 16fdf2c7111b b0714e37 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2025/04/23 19:09 linux-5.15.y f7347f400572 73a168d0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2025/03/10 20:03 linux-5.15.y c16c81c81336 16256247 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2025/02/18 01:03 linux-5.15.y c16c81c81336 429ea007 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2025/01/22 19:14 linux-5.15.y 4735586da88e a44b0418 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2025/01/18 05:16 linux-5.15.y 4735586da88e f2cb035c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2024/12/17 12:01 linux-5.15.y 963e654022cc f93b2b55 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2024/12/17 11:59 linux-5.15.y 963e654022cc f93b2b55 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2024/12/15 00:07 linux-5.15.y 963e654022cc 7cbfbb3a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2024/10/11 22:21 linux-5.15.y 3a5928702e71 084d8178 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2024/09/26 20:47 linux-5.15.y 3a5928702e71 9314348a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2024/08/21 20:08 linux-5.15.y fa93fa65db6e db5852f9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2024/07/25 23:15 linux-5.15.y 7c6d66f0266f 3f86dfed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2024/07/23 14:44 linux-5.15.y 7c6d66f0266f e50e8da5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2024/07/11 06:12 linux-5.15.y f45bea23c39c c699c2eb .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2024/07/05 09:52 linux-5.15.y f45bea23c39c 2a40360c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2024/06/25 22:47 linux-5.15.y 4878aadf2d15 dec8bc94 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2024/06/15 06:40 linux-5.15.y c61bd26ae81a f429ab00 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2024/06/10 19:39 linux-5.15.y c61bd26ae81a 048c640a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2024/05/31 15:37 linux-5.15.y c61bd26ae81a 0c378259 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2024/05/29 05:12 linux-5.15.y c61bd26ae81a 34889ee3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2024/05/24 04:24 linux-5.15.y 83655231580b 8f98448e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2024/05/20 20:20 linux-5.15.y 83655231580b c0f1611a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2024/05/10 00:57 linux-5.15.y 284087d4f7d5 de979bc2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2024/04/27 19:09 linux-5.15.y b925f60c6ee7 07b455f9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2024/04/16 00:47 linux-5.15.y fa3df276cd36 b9af7e61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2024/04/06 12:31 linux-5.15.y 9465fef4ae35 ca620dd8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2024/03/20 09:53 linux-5.15.y b95c01af2113 a485f239 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2024/03/01 19:52 linux-5.15.y 80efc6265290 83acf9e0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2023/12/14 00:10 linux-5.15.y d0fc081c6241 3222d10c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2023/12/12 03:03 linux-5.15.y 8a1d809b0545 28b24332 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2023/09/08 21:50 linux-5.15.y aff03380bda4 6654cf89 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2023/09/08 16:20 linux-5.15.y aff03380bda4 6654cf89 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
2023/07/13 03:08 linux-5.15.y d54cfc420586 86081196 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clock_settime
* Struck through repros no longer work on HEAD.