rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P3562/1:b..l
	(detected by 0, t=10503 jiffies, g=7993, q=147)
task:udevd           state:R  running task     stack:25104 pid: 3562 ppid:     1 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6571
 preempt_schedule+0xbc/0xd0 kernel/sched/core.c:6596
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
 _raw_spin_unlock_irqrestore+0x10d/0x120 kernel/locking/spinlock.c:194
 spin_unlock_irqrestore include/linux/spinlock.h:419 [inline]
 __wake_up_common_lock kernel/sched/wait.c:140 [inline]
 __wake_up_sync_key+0x128/0x190 kernel/sched/wait.c:205
 sock_def_readable+0x136/0x250 net/core/sock.c:3101
 __netlink_sendskb net/netlink/af_netlink.c:1264 [inline]
 netlink_sendskb+0x97/0x130 net/netlink/af_netlink.c:1270
 netlink_sendmsg+0x8ba/0xbe0 net/netlink/af_netlink.c:1918
 sock_sendmsg_nosec net/socket.c:706 [inline]
 __sock_sendmsg net/socket.c:718 [inline]
 ____sys_sendmsg+0x5b7/0x8f0 net/socket.c:2445
 ___sys_sendmsg+0x236/0x2e0 net/socket.c:2499
 __sys_sendmsg net/socket.c:2528 [inline]
 __do_sys_sendmsg net/socket.c:2537 [inline]
 __se_sys_sendmsg+0x1af/0x290 net/socket.c:2535
 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: 0033:0x7f8f5b517407
RSP: 002b:00007fffe75d8e30 EFLAGS: 00000202 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f8f5b429880 RCX: 00007f8f5b517407
RDX: 0000000000000000 RSI: 00007fffe75d8e90 RDI: 0000000000000004
RBP: 0000557ad02e39a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00000000000000b3
R13: 0000557ad02bf9e0 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
rcu: rcu_preempt kthread starved for 10532 jiffies! g7993 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:27800 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: 4648 Comm: syz.0.143 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
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+0x4b4/0xb70 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:__syscall_enter_from_user_work kernel/entry/common.c:93 [inline]
RIP: 0010:syscall_enter_from_user_mode+0x2a/0x70 kernel/entry/common.c:114
Code: 41 56 53 48 89 f3 49 89 fe 48 8b 7c 24 10 e8 3d f6 ff ff eb 31 eb 35 e8 f4 f1 c1 f7 e8 ef ef c1 f7 fb 65 48 8b 05 56 ea 44 76 <48> 8b 70 08 40 f6 c6 3f 74 0b 4c 89 f7 5b 41 5e e9 d1 ee a9 f7 48
RSP: 0018:ffffc900036aff08 EFLAGS: 00000286
RAX: ffff8880293cd940 RBX: 000000000000000f RCX: 8538e46ac4196b00
RDX: dffffc0000000000 RSI: ffffffff8a2b3180 RDI: ffffffff8a7a09c0
RBP: ffffc900036aff48 R08: ffffffff8d8a06ef R09: 1ffffffff1b140dd
R10: dffffc0000000000 R11: fffffbfff1b140de R12: 0000000000000000
R13: 0000000000000000 R14: ffffc900036aff58 R15: 0000000000000000
 do_syscall_64+0x24/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7ff319d281d9
Code: 11 06 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 90 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 c7 c0 0f 00 00 00 0f 05 <0f> 1f 80 00 00 00 00 48 81 ec 48 01 00 00 49 89 d0 64 48 8b 0c 25
RSP: 002b:00007ff3193e7b40 EFLAGS: 00000206 ORIG_RAX: 000000000000000f
RAX: ffffffffffffffda RBX: 00007ff319ffffa8 RCX: 00007ff319d281d9
RDX: 00007ff3193e7b40 RSI: 00007ff3193e7c70 RDI: 0000000000000021
RBP: 00007ff319ffffa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007ff31a000038 R14: 00007ffff8447e10 R15: 00007ffff8447ef8
 </TASK>