rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5159/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=12721, q=641 ncpus=2)
task:udevd           state:R  running task     stack:25160 pid:5159  ppid:1      flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5380 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
 preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6866
 preempt_schedule+0xab/0xc0 kernel/sched/core.c:6890
 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
 _raw_spin_unlock_irqrestore+0xfa/0x110 kernel/locking/spinlock.c:194
 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
 __wake_up_common_lock kernel/sched/wait.c:140 [inline]
 __wake_up_sync_key+0x11f/0x190 kernel/sched/wait.c:213
 sock_def_readable+0x1e1/0x430 net/core/sock.c:3354
 __netlink_sendskb net/netlink/af_netlink.c:1266 [inline]
 netlink_sendskb+0x9b/0x130 net/netlink/af_netlink.c:1272
 netlink_sendmsg+0x8c1/0xbe0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x5bf/0x950 net/socket.c:2595
 ___sys_sendmsg+0x220/0x290 net/socket.c:2649
 __sys_sendmsg net/socket.c:2678 [inline]
 __do_sys_sendmsg net/socket.c:2687 [inline]
 __se_sys_sendmsg+0x1a5/0x270 net/socket.c:2685
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7feb6caa7407
RSP: 002b:00007fffaf388000 EFLAGS: 00000202 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007feb6d194880 RCX: 00007feb6caa7407
RDX: 0000000000000000 RSI: 00007fffaf388060 RDI: 0000000000000004
RBP: 0000563855f2d1b0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00000000000000b3
R13: 0000563855f1a9e0 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
rcu: rcu_preempt kthread starved for 10337 jiffies! g12721 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:27752 pid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5380 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
 schedule+0xbd/0x170 kernel/sched/core.c:6773
 schedule_timeout+0x160/0x280 kernel/time/timer.c:2167
 rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667
 rcu_gp_kthread+0x99/0x380 kernel/rcu/tree.c:1866
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </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: 6084 Comm: vhost-6080 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:eventfd_signal_mask fs/eventfd.c:61 [inline]
RIP: 0010:eventfd_signal+0x73/0x1d0 fs/eventfd.c:90
Code: 00 00 41 0f b7 1e 89 de 81 e6 00 08 00 00 31 ff e8 32 1a 85 ff 81 e3 00 08 00 00 0f 85 04 01 00 00 49 8d 7f 08 48 89 7c 24 08 <e8> 78 5b 78 08 48 89 04 24 42 0f b6 44 25 00 84 c0 4c 89 e3 0f 85
RSP: 0018:ffffc90003557ae0 EFLAGS: 00000246
RAX: ffffffff8200896e RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff888023201e00 RSI: 0000000000000000 RDI: ffff88807ff80408
RBP: 1ffff1100464046e R08: ffff8880317169b7 R09: 1ffff110062e2d36
R10: dffffc0000000000 R11: ffffed10062e2d37 R12: dffffc0000000000
R13: 0000000000000001 R14: ffff888023202370 R15: ffff88807ff80400
FS:  00007fa5450fb6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000002 CR3: 0000000061a51000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 vhost_update_used_flags+0x1fa/0x290 drivers/vhost/vhost.c:2342
 vhost_enable_notify+0xb7/0x810 drivers/vhost/vhost.c:2899
 vhost_vsock_handle_tx_kick+0x2d6/0xdb0 drivers/vhost/vsock.c:504
 vhost_run_work_list+0x13d/0x1b0 drivers/vhost/vhost.c:419
 vhost_task_fn+0x25a/0x3c0 kernel/vhost_task.c:49
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>