rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P3546/1:b..l
	(detected by 0, t=10502 jiffies, g=10077, q=177)
task:udevd           state:R  running task     stack:24736 pid: 3546 ppid:     1 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5029 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6375
 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6551
 preempt_schedule+0xd9/0xe0 kernel/sched/core.c:6576
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
 __raw_spin_unlock include/linux/spinlock_api_smp.h:152 [inline]
 _raw_spin_unlock+0x36/0x40 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:403 [inline]
 __d_lookup+0x5be/0x730 fs/dcache.c:2446
 lookup_fast+0xdc/0x7b0 fs/namei.c:1621
 walk_component+0x115/0x610 fs/namei.c:1972
 link_path_walk+0x642/0xd90 fs/namei.c:-1
 path_lookupat+0xa9/0x450 fs/namei.c:2454
 filename_lookup+0x230/0x5c0 fs/namei.c:2484
 user_path_at_empty+0x40/0x180 fs/namei.c:2883
 user_path_at include/linux/namei.h:57 [inline]
 vfs_statx+0x106/0x3b0 fs/stat.c:221
 vfs_fstatat fs/stat.c:243 [inline]
 __do_sys_newfstatat fs/stat.c:411 [inline]
 __se_sys_newfstatat fs/stat.c:405 [inline]
 __x64_sys_newfstatat+0x12c/0x1b0 fs/stat.c:405
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fa54114c5f4
RSP: 002b:00007fff81925ef8 EFLAGS: 00000246 ORIG_RAX: 0000000000000106
RAX: ffffffffffffffda RBX: 000055af4ce2a7f0 RCX: 00007fa54114c5f4
RDX: 00007fff81925f08 RSI: 00007fff81926398 RDI: 00000000ffffff9c
RBP: 00007fff81925f98 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff81926398
R13: 00007fff81925f08 R14: 000055af4ce0e910 R15: 0000000000000000
 </TASK>
rcu: rcu_preempt kthread starved for 10532 jiffies! g10077 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:27000 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5029 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6375
 schedule+0x11b/0x1f0 kernel/sched/core.c:6458
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145
 kthread+0x3f6/0x4f0 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: 4827 Comm: syz-executor.3 Not tainted 5.15.179-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
 rcu_check_gp_kthread_starvation+0x1d2/0x240 kernel/rcu/tree_stall.h:487
 print_other_cpu_stall+0x137a/0x14d0 kernel/rcu/tree_stall.h:592
 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
 rcu_pending kernel/rcu/tree.c:3932 [inline]
 rcu_sched_clock_irq+0xa38/0x1150 kernel/rcu/tree.c:2619
 update_process_times+0x196/0x200 kernel/time/timer.c:1818
 tick_sched_handle kernel/time/tick-sched.c:254 [inline]
 tick_sched_timer+0x386/0x550 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1688 [inline]
 __hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1752
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1814
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x13b/0x4b0 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_irq include/linux/spinlock_api_smp.h:169 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202
Code: 31 60 f6 ff 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 ce 67 19 f7 48 89 df e8 26 bc 1a f7 e8 11 7c 3d f7 fb bf 01 00 00 00 <e8> 16 00 0e f7 65 8b 05 87 d0 b8 75 85 c0 74 02 5b c3 e8 54 ed b6
RSP: 0018:ffffc9000310fbc0 EFLAGS: 00000282
RAX: 4827fcbdef960c00 RBX: ffff8880672440c0 RCX: ffffffff96a95f03
RDX: dffffc0000000000 RSI: ffffffff8aab2a60 RDI: 0000000000000001
RBP: 0000000000000000 R08: ffffffff81871b70 R09: ffffed100ce48819
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000021
R13: dffffc0000000000 R14: ffff888067244558 R15: ffff8880672440c0
 spin_unlock_irq include/linux/spinlock.h:413 [inline]
 get_signal+0x13ee/0x14e0 kernel/signal.c:2903
 arch_do_signal_or_restart+0xc3/0x1890 arch/x86/kernel/signal.c:867
 handle_signal_work kernel/entry/common.c:154 [inline]
 exit_to_user_mode_loop+0x97/0x130 kernel/entry/common.c:178
 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+0x5d/0x240 kernel/entry/common.c:307
 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f7654a3ace7
Code: 14 25 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89
RSP: 002b:00007f7653dbc178 EFLAGS: 00000246
RAX: 00000000000000ca RBX: 00007f7654b59f88 RCX: 00007f7654a3ace9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f7654b59f88
RBP: 00007f7654b59f80 R08: 00007f7653dbc6c0 R09: 00007f7653dbc6c0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f7654b59f8c
R13: 000000000000000b R14: 00007ffcba04ebf0 R15: 00007ffcba04ecd8
 </TASK>