rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P6084/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=11881, q=259 ncpus=2)
task:udevd           state:R  running task     stack:26584 pid:6084  tgid:6084  ppid:5198   task_flags:0x400140 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5258 [inline]
 __schedule+0x150e/0x5070 kernel/sched/core.c:6866
 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7050
 preempt_schedule+0xae/0xc0 kernel/sched/core.c:7074
 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
 _raw_spin_unlock_irqrestore+0xfd/0x110 kernel/locking/spinlock.c:194
 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
 __wake_up_common_lock+0x190/0x1f0 kernel/sched/wait.c:127
 sock_def_readable+0x1eb/0x530 net/core/sock.c:3611
 unix_dgram_sendmsg+0xdfb/0x1840 net/unix/af_unix.c:2286
 sock_sendmsg_nosec+0x18f/0x1d0 net/socket.c:737
 __sock_sendmsg net/socket.c:752 [inline]
 sock_write_iter+0x2d9/0x3d0 net/socket.c:1210
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x5c9/0xb30 fs/read_write.c:686
 ksys_write+0x145/0x250 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0f2c2a7407
RSP: 002b:00007ffd01728cc0 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f0f2c9b7880 RCX: 00007f0f2c2a7407
RDX: 0000000000000000 RSI: 00007ffd01728d67 RDI: 000000000000000a
RBP: 000000000000000a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007f0f2c9b76e8
R13: 0000000000000000 R14: 0000000000000000 R15: 000055c25da76ba0
 </TASK>
rcu: rcu_preempt kthread starved for 10527 jiffies! g11881 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:27728 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5258 [inline]
 __schedule+0x150e/0x5070 kernel/sched/core.c:6866
 __schedule_loop kernel/sched/core.c:6948 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6963
 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6090 Comm: syz.3.20 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:check_preemption_disabled+0x1/0x120 lib/smp_processor_id.c:13
Code: 80 47 e2 8b 48 c7 c6 c0 47 e2 8b eb 1c 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 <41> 57 41 56 53 48 83 ec 10 65 48 8b 05 be e1 5c 07 48 89 44 24 08
RSP: 0018:ffffc90000007be8 EFLAGS: 00000046
RAX: ffffffffffffffff RBX: 0000000000000006 RCX: 5485f4c29f736700
RDX: 0000000000000000 RSI: ffffffff8dc93c7b RDI: ffffffff8be247e0
RBP: ffff88801db94830 R08: ffff88802f0340c3 R09: 1ffff11005e06818
R10: dffffc0000000000 R11: ffffed1005e06819 R12: 0000000000000000
R13: 0000000000000000 R14: ffff88801144a058 R15: ffff88801db93d00
FS:  00007f8af3fc56c0(0000) GS:ffff8881259dc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31663fff CR3: 0000000076e54000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 lockdep_recursion_finish kernel/locking/lockdep.c:470 [inline]
 lock_release+0x26b/0x3b0 kernel/locking/lockdep.c:5891
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline]
 _raw_spin_unlock_irqrestore+0x70/0x110 kernel/locking/spinlock.c:194
 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
 class_spinlock_irqsave_destructor include/linux/spinlock.h:585 [inline]
 posix_timer_fn+0x15c/0x1c0 kernel/time/posix-timers.c:381
 __run_hrtimer kernel/time/hrtimer.c:1777 [inline]
 __hrtimer_run_queues+0x51c/0xc30 kernel/time/hrtimer.c:1841
 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
 __sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202
Code: 90 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 1a fe 34 f6 48 89 df e8 52 75 35 f6 e8 4d f3 5f f6 fb bf 01 00 00 00 <e8> 82 6a 27 f6 65 8b 05 db 5f 5a 07 85 c0 74 07 5b e9 c1 4b 00 00
RSP: 0018:ffffc90003797c60 EFLAGS: 00000286
RAX: 5485f4c29f736700 RBX: ffff88802f0340c0 RCX: 5485f4c29f736700
RDX: 0000000000000000 RSI: ffffffff8daa9dc3 RDI: 0000000000000001
RBP: 0000000000000011 R08: ffffffff8fc3d077 R09: 1ffffffff1f87a0e
R10: dffffc0000000000 R11: fffffbfff1f87a0f R12: 1ffff11005e0686b
R13: 0000000000000000 R14: 0000000004000000 R15: ffff88802f034358
 spin_unlock_irq include/linux/spinlock.h:401 [inline]
 get_signal+0x11a7/0x1340 kernel/signal.c:3037
 arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
 exit_to_user_mode_loop+0x87/0x4f0 kernel/entry/common.c:75
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x2d0/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8af318f749
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:00007f8af3fc5038 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007f8af33e5fa0 RCX: 00007f8af318f749
RDX: 0000200000000240 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f8af3213f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8af33e6038 R14: 00007f8af33e5fa0 R15: 00007ffef6933ee8
 </TASK>