rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P10744/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=34797, q=184 ncpus=2)
task:syz.1.1580      state:R  running task     stack:27400 pid:10744 tgid:10743 ppid:10102  task_flags:0x480140 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5298 [inline]
 __schedule+0x1553/0x5240 kernel/sched/core.c:6911
 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7238
 irqentry_exit+0x599/0x620 kernel/entry/common.c:239
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x20b/0x2e0 kernel/locking/lockdep.c:5872
Code: e9 30 ff ff ff e8 95 79 83 09 f7 c3 00 02 00 00 0f 84 38 ff ff ff 65 48 8b 05 01 67 ae 10 48 3b 44 24 30 75 33 fb 48 83 c4 38 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d ee 4e cd
RSP: 0018:ffffc90005ba7238 EFLAGS: 00000282
RAX: 6ad24211e3497300 RBX: 0000000000000246 RCX: 0000000000000046
RDX: 0000000024779dae RSI: ffffffff8d7c095d RDI: ffffffff8ba67380
RBP: 0000000000000000 R08: ffffffff81767e65 R09: ffffffff8ddcb9c0
R10: ffffc90005ba7398 R11: ffffffff81af91d0 R12: 0000000000000002
R13: ffffffff8ddcb9c0 R14: 0000000000000000 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 rcu_read_lock include/linux/rcupdate.h:850 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
 unwind_next_frame+0xc2/0x23c0 arch/x86/kernel/unwind_orc.c:495
 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57
 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
 __call_rcu_common kernel/rcu/tree.c:3131 [inline]
 call_rcu+0xee/0x890 kernel/rcu/tree.c:3251
 kernfs_put+0x191/0x470 fs/kernfs/dir.c:591
 kernfs_remove_by_name_ns+0xb7/0x130 fs/kernfs/dir.c:1723
 device_remove_class_symlinks+0x17b/0x190 drivers/base/core.c:3479
 device_del+0x401/0x900 drivers/base/core.c:3866
 device_unregister drivers/base/core.c:3921 [inline]
 device_destroy+0xb2/0x1a0 drivers/base/core.c:4475
 comedi_free_subdevice_minor+0x11e/0x180 drivers/comedi/comedi_fops.c:3606
 comedi_device_detach_cleanup drivers/comedi/drivers.c:168 [inline]
 comedi_device_detach_locked+0x323/0x750 drivers/comedi/drivers.c:208
 do_devconfig_ioctl drivers/comedi/comedi_fops.c:904 [inline]
 comedi_unlocked_ioctl+0x128b/0x1b00 drivers/comedi/comedi_fops.c:2300
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xff/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7ce296c799
RSP: 002b:00007f7ce0bc6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f7ce2be5fa0 RCX: 00007f7ce296c799
RDX: 0000000000000000 RSI: 0000000040946400 RDI: 0000000000000006
RBP: 00007f7ce2a02c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7ce2be6038 R14: 00007f7ce2be5fa0 R15: 00007fff893bce08
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10497 jiffies! g34797 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=19905
rcu: rcu_preempt kthread starved for 10498 jiffies! g34797 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27728 pid:18    tgid:18    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5298 [inline]
 __schedule+0x1553/0x5240 kernel/sched/core.c:6911
 __schedule_loop kernel/sched/core.c:6993 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7008
 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095
 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 10750 Comm: vhost-10748 Tainted: G             L      syzkaller #0 PREEMPT_{RT,(full)} 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:194
Code: f7 e8 fd bd 79 f6 f7 c3 00 02 00 00 74 05 e8 40 35 a5 f6 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> d4 8a 6c f6 65 8b 05 dd 69 27 07 85 c0 74 18 5b 41 5e e9 41 3c
RSP: 0018:ffffc90006ed7b68 EFLAGS: 00000206
RAX: 0000000000000002 RBX: 0000000000000246 RCX: 0000000080000001
RDX: 0000000000000006 RSI: ffffffff8d5642eb RDI: 0000000000000001
RBP: ffffc90006ed7c80 R08: ffffffff8f6a64b7 R09: 1ffffffff1ed4c96
R10: dffffc0000000000 R11: fffffbfff1ed4c97 R12: dffffc0000000000
R13: 1ffff92000ddaf78 R14: ffffffff8de282e0 R15: ffffffff8de282e0
FS:  00007ff949c6e6c0(0000) GS:ffff888126436000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4dfe941053 CR3: 0000000033260000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 unlock_rt_mutex_safe kernel/locking/rtmutex.c:344 [inline]
 rt_mutex_slowunlock+0x4a7/0x8b0 kernel/locking/rtmutex.c:1454
 spin_unlock include/linux/spinlock_rt.h:109 [inline]
 kcov_remote_stop+0x47e/0x680 kernel/kcov.c:1075
 vhost_run_work_list+0x152/0x1e0 drivers/vhost/vhost.c:455
 vhost_task_fn+0x2ef/0x4a0 kernel/vhost_task.c:49
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>