rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
	(detected by 1, t=10502 jiffies, g=9565, q=112)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295036372-4295025870), jiffies_till_next_fqs=1, root ->qsmask 0x0
syz-executor858 R  running task    26712 10362   9589 0x00004000
Call Trace:
 <IRQ>
 sched_show_task kernel/sched/core.c:5954 [inline]
 sched_show_task.cold+0x2ee/0x35d kernel/sched/core.c:5929
 print_other_cpu_stall kernel/rcu/tree_stall.h:410 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:538 [inline]
 rcu_pending kernel/rcu/tree.c:2827 [inline]
 rcu_sched_clock_irq.cold+0xaf4/0xc02 kernel/rcu/tree.c:2271
 update_process_times+0x2d/0x70 kernel/time/timer.c:1726
 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:167
 tick_sched_timer+0x53/0x140 kernel/time/tick-sched.c:1310
 __run_hrtimer kernel/time/hrtimer.c:1517 [inline]
 __hrtimer_run_queues+0x364/0xe40 kernel/time/hrtimer.c:1579
 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1641
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline]
 smp_apic_timer_interrupt+0x160/0x610 arch/x86/kernel/apic/apic.c:1135
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 </IRQ>
RIP: 0010:mutex_unlock+0xd/0x30 kernel/locking/mutex.c:735
Code: c7 c7 20 c5 63 8b e8 f2 38 eb f9 e9 03 fe ff ff 4c 89 ff e8 05 39 eb f9 e9 8c fb ff ff 55 65 8b 05 00 91 3a 78 a9 00 ff 1f 00 <48> 89 e5 75 0b 48 8b 75 08 e8 45 f9 ff ff 5d c3 0f 0b 48 8b 75 08
RSP: 0018:ffffc90002d577f8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000080000000 RBX: 0000000000005401 RCX: ffffffff83dc49dc
RDX: 0000000000000000 RSI: ffffffff83dc49e9 RDI: ffff88809fd45138
RBP: ffffc90002d57818 R08: ffff8880a469e0c0 R09: ffffed1013fa8a01
R10: ffffed1013fa8a00 R11: ffff88809fd45007 R12: ffff88809fd45000
R13: ffff8880938b7800 R14: ffff888218b93900 R15: dffffc0000000000
 tty_open_by_driver drivers/tty/tty_io.c:1983 [inline]
 tty_open+0x882/0xbb0 drivers/tty/tty_io.c:2035
 chrdev_open+0x245/0x6b0 fs/char_dev.c:414
 do_dentry_open+0x4e6/0x1380 fs/open.c:797
 vfs_open+0xa0/0xd0 fs/open.c:914
 do_last fs/namei.c:3420 [inline]
 path_openat+0x10df/0x4500 fs/namei.c:3537
 do_filp_open+0x1a1/0x280 fs/namei.c:3567
 do_sys_open+0x3fe/0x5d0 fs/open.c:1097
 __do_sys_openat fs/open.c:1124 [inline]
 __se_sys_openat fs/open.c:1118 [inline]
 __x64_sys_openat+0x9d/0x100 fs/open.c:1118
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4468f9
Code: e8 0c e8 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 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 0f 83 5b 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f2706ab2db8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00000000006dbc28 RCX: 00000000004468f9
RDX: 0000000000000000 RSI: 0000000020000380 RDI: ffffffffffffff9c
RBP: 00000000006dbc20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c
R13: 00007ffd66fb241f R14: 00007f2706ab39c0 R15: 000000000000002d
rcu: rcu_preempt kthread starved for 10502 jiffies! g9565 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: RCU grace-period kthread stack dump:
rcu_preempt     R  running task    29272    10      2 0x80004000
Call Trace:
 context_switch kernel/sched/core.c:3385 [inline]
 __schedule+0x934/0x1f90 kernel/sched/core.c:4081
 schedule+0xdc/0x2b0 kernel/sched/core.c:4155
 schedule_timeout+0x486/0xc50 kernel/time/timer.c:1895
 rcu_gp_fqs_loop kernel/rcu/tree.c:1661 [inline]
 rcu_gp_kthread+0x9b2/0x18d0 kernel/rcu/tree.c:1821
 kthread+0x361/0x430 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352