rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P4319/1:b..l
	(detected by 0, t=10502 jiffies, g=15293, q=90)
task:udevd           state:R  running task     stack:24544 pid: 4319 ppid:  3547 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6777
 irqentry_exit+0x53/0x80 kernel/entry/common.c:432
 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:681
RIP: 0010:_raw_spin_lock_irqsave+0x3d/0x120 kernel/locking/spinlock.c:161
Code: ec 60 49 89 fe 65 48 8b 04 25 28 00 00 00 48 89 44 24 40 49 bf 00 00 00 00 00 fc ff df 4c 8d 64 24 20 48 c7 04 24 b3 8a b5 41 <48> c7 44 24 08 9a 29 19 8c 48 c7 44 24 10 a0 93 3d 8a 49 89 e5 49
RSP: 0018:ffffc900032077e0 EFLAGS: 00000282
RAX: c6814fb406682f00 RBX: 0000000000000001 RCX: 0000000000000000
RDX: 0000000000000018 RSI: 0000000000000000 RDI: ffff888147af5a40
RBP: ffffc90003207870 R08: dffffc0000000000 R09: ffffc900032078c0
R10: 0000000000000000 R11: dffffc0000000001 R12: ffffc90003207800
R13: ffff888147af5a40 R14: ffff888147af5a40 R15: dffffc0000000000
 __wake_up_common_lock kernel/sched/wait.c:137 [inline]
 __wake_up_sync_key+0xf5/0x1c0 kernel/sched/wait.c:205
 sock_def_readable+0x135/0x240 net/core/sock.c:3092
 unix_dgram_sendmsg+0x15fc/0x2090 net/unix/af_unix.c:1935
 sock_sendmsg_nosec net/socket.c:704 [inline]
 __sock_sendmsg net/socket.c:716 [inline]
 sock_write_iter+0x39b/0x530 net/socket.c:1079
 call_write_iter include/linux/fs.h:2174 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0xacd/0xe50 fs/read_write.c:594
 ksys_write+0x1a2/0x2c0 fs/read_write.c:647
 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: 0033:0x7fd5918adbf2
RSP: 002b:00007fffabc31b08 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fd5918adbf2
RDX: 0000000000000000 RSI: 00007fffabc31b5f RDI: 000000000000000a
RBP: 00007fffabc31b5f R08: 0000000000000001 R09: 0000000000000000
R10: 000000000000010f R11: 0000000000000246 R12: 000000000000000a
R13: 00007fd591782ae0 R14: 0000000000000000 R15: 0000561158511910
 </TASK>
rcu: rcu_preempt kthread starved for 10526 jiffies! g15293 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:26488 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373
 schedule+0x11b/0x1f0 kernel/sched/core.c:6456
 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: 5662 Comm: syz.1.274 Not tainted 5.15.169-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
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: 51 67 f6 ff 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 4e 4b 25 f7 48 89 df e8 a6 9f 26 f7 e8 91 5a 49 f7 fb bf 01 00 00 00 <e8> 06 e5 19 f7 65 8b 05 17 d8 c4 75 85 c0 74 02 5b c3 e8 e4 f4 c2
RSP: 0018:ffffc90002e07bc0 EFLAGS: 00000282
RAX: f56f2be01d6f1e00 RBX: ffff88801c082e40 RCX: ffffffff96869f03
RDX: dffffc0000000000 RSI: ffffffff8a8b2a80 RDI: 0000000000000001
RBP: 0000000000000000 R08: ffffffff8186f260 R09: ffffed10038105c9
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000021
R13: dffffc0000000000 R14: ffff88801c0832d8 R15: ffff88801c082e40
 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: 0033:0x7fa8b49bb805
Code: 24 0c 89 3c 24 48 89 4c 24 18 e8 c6 57 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 8b 74 24 0c 8b 3c 24 b8 e6 00 00 00 0f 05 <44> 89 c7 48 89 04 24 e8 1f 58 ff ff 48 8b 04 24 48 83 c4 28 f7 d8
RSP: 002b:00007fff147be250 EFLAGS: 00000293
RAX: fffffffffffffffc RBX: 00007fa8b4b40f80 RCX: 00007fa8b49bb805
RDX: 00007fff147be290 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fa8b4b42a80 R08: 0000000000000000 R09: 0000000000000010
R10: 0000000000000000 R11: 0000000000000293 R12: 000000000002dad0
R13: 00007fff147be3c0 R14: 0000000000000032 R15: ffffffffffffffff
 </TASK>