rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5905/1:b..l
	(detected by 0, t=10502 jiffies, g=24173, q=98)
task:udevd           state:R  running task     stack:23168 pid: 5905 ppid:  3546 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6552
 preempt_schedule+0xa7/0xb0 kernel/sched/core.c:6577
 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
 unix_dgram_sendmsg+0x11ed/0x1890 net/unix/af_unix.c:1935
 sock_sendmsg_nosec net/socket.c:704 [inline]
 __sock_sendmsg net/socket.c:716 [inline]
 sock_write_iter+0x29c/0x380 net/socket.c:1079
 call_write_iter include/linux/fs.h:2172 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x712/0xd00 fs/read_write.c:594
 ksys_write+0x14d/0x250 fs/read_write.c:647
 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: 0033:0x7f1fc4dcc407
RSP: 002b:00007fff86969540 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f1fc4cde880 RCX: 00007f1fc4dcc407
RDX: 0000000000000000 RSI: 00007fff869695e7 RDI: 000000000000000a
RBP: 000000000000000a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007f1fc4cde6e8
R13: 0000000000000000 R14: 0000000000000000 R15: 00005646157a3db0
 </TASK>
rcu: rcu_preempt kthread starved for 10526 jiffies! g24173 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
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:28032 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1e0 kernel/sched/core.c:6459
 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:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 7638 Comm: syz.7.939 Not tainted 5.15.184-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:instrument_atomic_read include/linux/instrumented.h:71 [inline]
RIP: 0010:test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline]
RIP: 0010:test_ti_thread_flag include/linux/thread_info.h:118 [inline]
RIP: 0010:test_tsk_thread_flag include/linux/sched.h:1994 [inline]
RIP: 0010:task_sigpending include/linux/sched/signal.h:364 [inline]
RIP: 0010:retarget_shared_pending+0x197/0x260 kernel/signal.c:2974
Code: 50 ff ff ff 44 89 e1 80 e1 07 80 c1 03 38 c1 0f 8c 5a ff ff ff 4c 89 e7 e8 26 51 72 00 e9 4d ff ff ff 4c 89 f7 be 08 00 00 00 <e8> b4 52 72 00 4c 89 f0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 f7
RSP: 0018:ffffc90002f0fad0 EFLAGS: 00000006
RAX: ffffffff814ae576 RBX: ffff888017bbbb80 RCX: ffff888017bbbb80
RDX: 0000000000000002 RSI: 0000000000000008 RDI: ffff888063c69dc0
RBP: 0000000100000000 R08: dffffc0000000000 R09: ffffed1002f77771
R10: ffffed1002f77771 R11: 1ffff11002f77770 R12: 0000000000000000
R13: dffffc0000000000 R14: ffff888063c69dc0 R15: 0000000100000000
FS:  00007fea280a26c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000006b000 CR3: 0000000064152000 CR4: 00000000003506e0
DR0: 0000000000009593 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __set_task_blocked kernel/signal.c:3056 [inline]
 __set_current_blocked+0x1b9/0x240 kernel/signal.c:3087
 set_current_blocked kernel/signal.c:3072 [inline]
 signal_delivered kernel/signal.c:2936 [inline]
 signal_setup_done+0x28c/0x440 kernel/signal.c:2947
 handle_signal arch/x86/kernel/signal.c:842 [inline]
 arch_do_signal_or_restart+0xf2e/0x1300 arch/x86/kernel/signal.c:869
 handle_signal_work kernel/entry/common.c:154 [inline]
 exit_to_user_mode_loop+0x9e/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+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fea2a2840a0
Code: 83 c0 16 83 e0 f7 74 12 50 48 8d 3d 2a 26 08 00 e8 f5 8f f8 ff 0f 1f 44 00 00 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 <83> ff 21 74 0b c3 66 2e 0f 1f 84 00 00 00 00 00 55 53 48 89 f3 48
RSP: 002b:00007fea280a1b38 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007fea2a483088 RCX: 00007fea2a25b969
RDX: 00007fea280a1b40 RSI: 00007fea280a1c70 RDI: 0000000000000021
RBP: 00007fea2a483080 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fea2a48308c
R13: 0000000000000000 R14: 00007ffd32147e40 R15: 00007ffd32147f28
 </TASK>