rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P4432/1:b..l
	(detected by 0, t=10503 jiffies, g=34633, q=256)
task:udevd           state:R  running task     stack:23952 pid: 4432 ppid:  3562 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799
 irqentry_exit+0x63/0x70 kernel/entry/common.c:432
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:hlist_bl_first_rcu include/linux/rculist_bl.h:24 [inline]
RIP: 0010:__d_lookup+0x111/0x760 fs/dcache.c:2432
Code: 02 00 00 48 c7 c2 e0 e1 36 8a e8 9a 67 e2 07 4c 89 7c 24 08 4d 89 ee 49 c1 ee 03 43 80 3c 26 00 74 08 4c 89 ef e8 6f 3e ef ff <4d> 8b 7d 00 e8 c6 3e ed 07 89 c3 31 ff 89 c6 e8 db 35 aa ff 85 db
RSP: 0018:ffffc90003457700 EFLAGS: 00000246
RAX: ffffffff81ceef3e RBX: 0000000000000001 RCX: ffff888022775940
RDX: 0000000000000000 RSI: ffffffff8a79f7e0 RDI: ffffffff8a79f7a0
RBP: ffff888020b76468 R08: dffffc0000000000 R09: 1ffffffff203a618
R10: dffffc0000000000 R11: fffffbfff203a619 R12: dffffc0000000000
R13: ffffc900000e1108 R14: 1ffff9200001c221 R15: ffffc90003457af0
 lookup_fast+0xd7/0x720 fs/namei.c:1629
 walk_component+0x81/0x460 fs/namei.c:1980
 link_path_walk+0x665/0xd70 fs/namei.c:-1
 path_lookupat+0x9d/0x440 fs/namei.c:2462
 filename_lookup+0x214/0x540 fs/namei.c:2492
 user_path_at_empty+0x40/0x190 fs/namei.c:2891
 user_path_at include/linux/namei.h:57 [inline]
 vfs_statx+0x107/0x500 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+0x15f/0x200 fs/stat.c:405
 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: 0033:0x7f00f20d4b0a
RSP: 002b:00007ffc56f15e18 EFLAGS: 00000202 ORIG_RAX: 0000000000000106
RAX: ffffffffffffffda RBX: 000055e0b120abd1 RCX: 00007f00f20d4b0a
RDX: 00007ffc56f15e20 RSI: 00007ffc56f15eb0 RDI: 00000000ffffff9c
RBP: 000055e0b1228b40 R08: 000055e0b120abd1 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000202 R12: 000055e0b1228c30
R13: 00007ffc56f15eb0 R14: 000055e0b11de64c R15: 000055e086f57bcc
 </TASK>
rcu: rcu_preempt kthread starved for 9662 jiffies! g34633 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:26864 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117
 rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x9b/0x370 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 02/12/2026
Call Trace:
 <IRQ>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a2/0x3d0 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+0x1110/0x1270 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+0x843/0x1120 kernel/rcu/tree.c:2619
 update_process_times+0x193/0x200 kernel/time/timer.c:2021
 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+0x4ad/0xb70 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: b7 48 89 df e8 16 b5 f8 f7 eb ad e8 4f af f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 00 cc 66 90 0f 00 2d 77 56 60 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:ffffffff8c007dc8 EFLAGS: 000002c6
RAX: 7cbae67f54744e00 RBX: ffffffff8c0bc480 RCX: 7cbae67f54744e00
RDX: 0000000000000001 RSI: ffffffff8a2b2780 RDI: ffffffff8a79f800
RBP: ffffffff8c007ef8 R08: ffff8880b903b30b R09: 1ffff11017207661
R10: dffffc0000000000 R11: ffffed1017207662 R12: 1ffffffff1817890
R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffffffff1800fc4
 default_idle_call+0x81/0xc0 kernel/sched/idle.c:112
 cpuidle_idle_call kernel/sched/idle.c:194 [inline]
 do_idle+0x21f/0x580 kernel/sched/idle.c:306
 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:403
 start_kernel+0x489/0x540 init/main.c:1154
 secondary_startup_64_no_verify+0xb1/0xbb
 </TASK>