INFO: rcu detected stall in sys

Kernel	Title	Rank 🛈	Repro	Fix bisect	Count	Last	Reported	Patched	Status
upstream	INFO: rcu detected stall in sys_utimensat (3) usb	1	C		9	559d	578d	0/29	auto-obsoleted due to no activity on 2025/01/29 23:25
upstream	INFO: rcu detected stall in sys_utimensat (2) fs	1			1	1605d	1605d	0/29	closed as invalid on 2022/02/08 10:00
linux-5.15	INFO: rcu detected stall in sys_utimensat origin:lts-only	1	C	error	4	27d	288d	0/3	upstream: reported C repro on 2025/07/19 08:31
upstream	INFO: rcu detected stall in sys_utimensat (4) fs	1			5	127d	163d	0/29	auto-obsoleted due to no activity on 2026/03/27 23:33

rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10499 ticks this GP) idle=0fa/1/0x4000000000000002 softirq=10679/10688 fqs=0 (t=10501 jiffies g=6209 q=60) rcu: rcu_preempt kthread starved for 10502 jiffies! g6209 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 29032 10 2 0x80004000 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x9a0/0xcc0 kernel/sched/core.c:4081 schedule+0x181/0x210 kernel/sched/core.c:4155 schedule_timeout+0x14f/0x240 kernel/time/timer.c:1895 rcu_gp_fqs_loop kernel/rcu/tree.c:1661 [inline] rcu_gp_kthread+0xed8/0x1770 kernel/rcu/tree.c:1821 kthread+0x332/0x350 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 NMI backtrace for cpu 0 CPU: 0 PID: 7786 Comm: udevd Not tainted 5.4.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fb/0x318 lib/dump_stack.c:118 nmi_cpu_backtrace+0xaf/0x1a0 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x174/0x290 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x10/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x15a/0x220 kernel/rcu/tree_stall.h:254 print_cpu_stall kernel/rcu/tree_stall.h:455 [inline] check_cpu_stall kernel/rcu/tree_stall.h:529 [inline] rcu_pending kernel/rcu/tree.c:2827 [inline] rcu_sched_clock_irq+0xe25/0x1ad0 kernel/rcu/tree.c:2271 update_process_times+0x12d/0x180 kernel/time/timer.c:1726 tick_sched_handle kernel/time/tick-sched.c:167 [inline] tick_sched_timer+0x263/0x420 kernel/time/tick-sched.c:1310 __run_hrtimer kernel/time/hrtimer.c:1514 [inline] __hrtimer_run_queues+0x403/0x840 kernel/time/hrtimer.c:1576 hrtimer_interrupt+0x38c/0xda0 kernel/time/hrtimer.c:1638 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline] smp_apic_timer_interrupt+0x109/0x280 arch/x86/kernel/apic/apic.c:1135 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 </IRQ> RIP: 0010:free_thread_stack+0x12e/0x590 kernel/fork.c:280 Code: bf 00 00 00 00 00 ea ff ff 48 01 c7 be 03 00 00 00 e8 06 a2 60 00 e9 5d 04 00 00 e8 5c 2d 2e 00 48 89 df 31 f6 e8 42 af 6e 00 <43> 80 3c 2e 00 74 08 4c 89 e7 e8 43 a4 69 00 49 8b 1c 24 48 83 c3 RSP: 0018:ffffc90006dc7b18 EFLAGS: 00000292 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000001 RBX: ffffea000280a700 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffea000280a700 RBP: ffffc90006dc7b50 R08: dffffc0000000000 R09: fffffbfff120248a R10: fffffbfff120248a R11: 0000000000000000 R12: ffff8880a81f4fa0 R13: dffffc0000000000 R14: 1ffff1101503e9f4 R15: ffff8880a800d568 release_task_stack kernel/fork.c:440 [inline] put_task_stack+0xa3/0x130 kernel/fork.c:451 finish_task_switch+0x3f1/0x550 kernel/sched/core.c:3256 context_switch kernel/sched/core.c:3388 [inline] __schedule+0x9a8/0xcc0 kernel/sched/core.c:4081 preempt_schedule_irq+0xc1/0x140 kernel/sched/core.c:4338 retint_kernel+0x1b/0x2b RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:752 [inline] RIP: 0010:slab_alloc mm/slab.c:3313 [inline] RIP: 0010:kmem_cache_alloc+0x1a8/0x2e0 mm/slab.c:3484 Code: 8b 7d d0 57 9d 0f 1f 44 00 00 e8 83 b1 ca ff eb 1e e8 1c af ca ff 48 83 3d 7c 10 59 07 00 0f 84 33 01 00 00 48 8b 7d d0 57 9d <0f> 1f 44 00 00 41 0f 18 0e e9 21 00 00 00 89 d8 c1 e8 08 83 e0 01 RSP: 0018:ffffc90006dc7d68 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: ffff8880a3966b54 RBX: 0000000000000cc0 RCX: ffff8880a39662c0 RDX: 0000000000000000 RSI: ffffffff81be59ca RDI: 0000000000000286 RBP: ffffc90006dc7da0 R08: ffff8880a3966b18 R09: ffffed101553fbc1 R10: ffffed101553fbc1 R11: 0000000000000000 R12: ffff8880aa9f9a80 R13: ffff8880aa9f9a80 R14: ffff88806c200800 R15: 0000000000000cc0 getname_flags+0xba/0x640 fs/namei.c:138 user_path_at_empty+0x2d/0x50 fs/namei.c:2602 user_path_at include/linux/namei.h:49 [inline] do_utimes+0x1fe/0x2d0 fs/utimes.c:121 __do_sys_utimensat fs/utimes.c:153 [inline] __se_sys_utimensat fs/utimes.c:137 [inline] __x64_sys_utimensat+0xfb/0x1e0 fs/utimes.c:137 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7efc31dc7a32 Code: 2b 00 31 d2 48 29 c2 64 89 11 48 83 c8 ff eb ea 90 90 90 90 90 90 90 90 48 85 f6 74 2b 4c 63 d1 48 63 ff b8 18 01 00 00 0f 05 <48> 3d 00 f0 ff ff 77 02 f3 c3 48 8b 15 d5 33 2b 00 f7 d8 64 89 02 RSP: 002b:00007fffd8f2dd78 EFLAGS: 00000206 ORIG_RAX: 0000000000000118 RAX: ffffffffffffffda RBX: 000000000141e600 RCX: 00007efc31dc7a32 RDX: 0000000000000000 RSI: 000000000141e600 RDI: ffffffffffffff9c RBP: 0000000001405250 R08: 0000000000000006 R09: 00007efc31e1c1d0 R10: 0000000000000000 R11: 0000000000000206 R12: 00000000000063b0 R13: 0000000000002b00 R14: 0000000000000000 R15: 0000000000000000