rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P3563/1:b..l
	(detected by 0, t=10502 jiffies, g=26289, q=135)
task:udevd           state:R  running task     stack:23392 pid: 3563 ppid:     1 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11bb/0x4390 kernel/sched/core.c:6395
 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6571
 preempt_schedule+0xa7/0xb0 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+0xf6/0x100 kernel/locking/spinlock.c:194
 spin_unlock_irqrestore include/linux/spinlock.h:418 [inline]
 __wake_up_common_lock kernel/sched/wait.c:140 [inline]
 __wake_up_sync_key+0x11b/0x180 kernel/sched/wait.c:205
 sock_def_readable+0x136/0x250 net/core/sock.c:3093
 __netlink_sendskb net/netlink/af_netlink.c:1264 [inline]
 netlink_sendskb+0x97/0x130 net/netlink/af_netlink.c:1270
 netlink_sendmsg+0x8ab/0xbc0 net/netlink/af_netlink.c:1918
 sock_sendmsg_nosec net/socket.c:704 [inline]
 __sock_sendmsg net/socket.c:716 [inline]
 ____sys_sendmsg+0x5a2/0x8c0 net/socket.c:2436
 ___sys_sendmsg+0x1f0/0x260 net/socket.c:2490
 __sys_sendmsg net/socket.c:2519 [inline]
 __do_sys_sendmsg net/socket.c:2528 [inline]
 __se_sys_sendmsg+0x190/0x250 net/socket.c:2526
 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: 0033:0x7fcf0d0f9407
RSP: 002b:00007ffddd60a680 EFLAGS: 00000202 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fcf0d00b880 RCX: 00007fcf0d0f9407
RDX: 0000000000000000 RSI: 00007ffddd60a6e0 RDI: 0000000000000004
RBP: 0000556b4980cf90 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00000000000000b4
R13: 0000556b497e89e0 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
rcu: rcu_preempt kthread starved for 10514 jiffies! g26289 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:27808 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: 7824 Comm: syz.5.684 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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:1690 [inline]
 __hrtimer_run_queues+0x4fe/0xc40 kernel/time/hrtimer.c:1754
 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816
 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_rq_unlock_irq+0x13/0x90 kernel/sched/sched.h:1339
Code: c0 48 8b 3c 24 e8 0d be 68 00 eb b5 66 2e 0f 1f 84 00 00 00 00 00 90 41 57 41 56 53 66 90 e8 44 e6 5e 08 e8 1f 74 2a 00 fb 5b <41> 5e 41 5f c3 49 be 00 00 00 00 00 fc ff df 49 89 ff 48 8d 9f 58
RSP: 0018:ffffc90002f2f848 EFLAGS: 00000286
RAX: b0cbd13071843000 RBX: ffff8880b903a300 RCX: b0cbd13071843000
RDX: dffffc0000000000 RSI: ffffffff8a0b1620 RDI: ffffffff8a59a240
RBP: ffffc90002f2fa40 R08: dffffc0000000000 R09: ffffed1017207461
R10: ffffed1017207461 R11: 1ffff11017207460 R12: 1ffff110172075a3
R13: dffffc0000000000 R14: ffff88807c3dd940 R15: ffff88807c3dd940
 __schedule+0x1464/0x4390 kernel/sched/core.c:6401
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 freezable_schedule include/linux/freezer.h:172 [inline]
 futex_wait_queue_me+0x22d/0x440 kernel/futex/core.c:2863
 futex_wait+0x202/0x5c0 kernel/futex/core.c:2964
 do_futex+0xd1c/0x1240 kernel/futex/core.c:3982
 __do_sys_futex kernel/futex/core.c:4059 [inline]
 __se_sys_futex+0x3a3/0x430 kernel/futex/core.c:4040
 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: 0033:0x7f7af9f4dba9
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:00007f7af81b50e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f7afa194fa8 RCX: 00007f7af9f4dba9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f7afa194fa8
RBP: 00007f7afa194fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7afa195038 R14: 00007ffcbf0d42d0 R15: 00007ffcbf0d43b8
 </TASK>