rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (10500 ticks this GP) idle=bce/1/0x4000000000000004 softirq=37568/37568 fqs=5210 
rcu: 	 (t=10500 jiffies g=25457 q=253)
NMI backtrace for cpu 0
CPU: 0 PID: 2060 Comm: syz-executor.4 Not tainted 4.19.122-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x123/0x177 lib/dump_stack.c:118
 nmi_cpu_backtrace.cold.4+0x3e/0x76 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0xe6/0x11a lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x175/0x1c2 kernel/rcu/tree.c:1340
 print_cpu_stall kernel/rcu/tree.c:1478 [inline]
 check_cpu_stall kernel/rcu/tree.c:1550 [inline]
 __rcu_pending kernel/rcu/tree.c:3293 [inline]
 rcu_pending kernel/rcu/tree.c:3336 [inline]
 rcu_check_callbacks.cold.81+0x5cc/0xd67 kernel/rcu/tree.c:2682
 update_process_times+0x2a/0x60 kernel/time/timer.c:1638
 tick_sched_handle+0x77/0x140 kernel/time/tick-sched.c:168
 tick_sched_timer+0x37/0xf0 kernel/time/tick-sched.c:1278
 __run_hrtimer kernel/time/hrtimer.c:1401 [inline]
 __hrtimer_run_queues+0x2f7/0xab0 kernel/time/hrtimer.c:1463
 hrtimer_interrupt+0x2df/0x760 kernel/time/hrtimer.c:1521
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1067 [inline]
 smp_apic_timer_interrupt+0x114/0x540 arch/x86/kernel/apic/apic.c:1092
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:893
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:789 [inline]
RIP: 0010:lock_is_held_type+0x18b/0x210 kernel/locking/lockdep.c:3947
Code: ff df 41 c7 84 24 84 08 00 00 00 00 00 00 48 89 fa 48 c1 ea 03 80 3c 02 00 75 63 48 83 3d f4 b6 c6 06 00 74 30 48 89 df 57 9d <0f> 1f 44 00 00 48 83 c4 08 44 89 e8 5b 41 5c 41 5d 5d c3 48 83 c4
RSP: 0018:ffff8880aea07cd8 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: dffffc0000000000 RBX: 0000000000000286 RCX: 0000000000000000
RDX: 1ffffffff10240e9 RSI: ffffffff88199e20 RDI: 0000000000000286
RBP: ffff8880aea07cf8 R08: ffffed1015d44733 R09: ffffed1015d44732
R10: ffffed1015d44732 R11: ffff8880aea23993 R12: ffff88809a7523c0
R13: 0000000000000000 R14: 1ffff11015d40fa8 R15: ffff8880aea23a00
 lock_is_held include/linux/lockdep.h:344 [inline]
 rcu_read_lock_sched_held+0x108/0x120 kernel/rcu/update.c:118
 trace_timer_expire_entry include/trace/events/timer.h:90 [inline]
 call_timer_fn+0x46b/0x510 kernel/time/timer.c:1325
 expire_timers kernel/time/timer.c:1363 [inline]
 __run_timers kernel/time/timer.c:1684 [inline]
 run_timer_softirq+0xb63/0x1180 kernel/time/timer.c:1697
 __do_softirq+0x260/0x92d kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:372 [inline]
 irq_exit+0x17f/0x1c0 kernel/softirq.c:412
 exiting_irq arch/x86/include/asm/apic.h:544 [inline]
 smp_apic_timer_interrupt+0x13e/0x540 arch/x86/kernel/apic/apic.c:1094
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:893
 </IRQ>
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:789 [inline]
RIP: 0010:lock_release+0x44e/0x850 kernel/locking/lockdep.c:3929
Code: 00 00 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 f8 02 00 00 48 83 3d c9 e9 c5 06 00 0f 84 49 02 00 00 48 8b bd 68 ff ff ff 57 9d <0f> 1f 44 00 00 48 b8 00 00 00 00 00 fc ff df 48 c7 04 03 00 00 00
RSP: 0018:ffff88805e617718 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: dffffc0000000000 RBX: 1ffff1100bcc2ee7 RCX: 1ffff110134ea592
RDX: 1ffffffff10240e9 RSI: 0000000000000000 RDI: 0000000000000286
RBP: ffff88805e6177c0 R08: 0000000000005611 R09: 0000000000000001
R10: ffff88809a752c70 R11: 0000000000000001 R12: ffff88809a7523c0
R13: 0000000000000002 R14: 0000000000000000 R15: ffff88809a7523c0
 rcu_lock_release include/linux/rcupdate.h:247 [inline]
 rcu_read_unlock include/linux/rcupdate.h:681 [inline]
 mntput_no_expire+0x24d/0x760 fs/namespace.c:1154
 mntput fs/namespace.c:1187 [inline]
 drop_mountpoint+0x80/0xa0 fs/namespace.c:174
 pin_kill+0x140/0x640 fs/fs_pin.c:50
 group_pin_kill+0x44/0x120 fs/fs_pin.c:101
 namespace_unlock+0xe0/0xf0 fs/namespace.c:1365
 drop_collected_mounts+0x7d/0x90 fs/namespace.c:1799
 put_mnt_ns+0x42/0x60 fs/namespace.c:3248
 free_nsproxy+0x37/0x1a0 kernel/nsproxy.c:176
 switch_task_namespaces+0x91/0xb0 kernel/nsproxy.c:229
 exit_task_namespaces+0xb/0x10 kernel/nsproxy.c:234
 do_exit+0xa5d/0x2d20 kernel/exit.c:879
 do_group_exit+0xf4/0x2f0 kernel/exit.c:983
 get_signal+0x313/0x1a00 kernel/signal.c:2588
 do_signal+0x87/0x1960 arch/x86/kernel/signal.c:821
 exit_to_usermode_loop+0x114/0x200 arch/x86/entry/common.c:163
 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
 do_syscall_64+0x413/0x4e0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459a09
Code: Bad RIP value.
RSP: 002b:00007f554da51c78 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: 0000000000000006 RBX: 0000000000000005 RCX: 0000000000459a09
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 000000002001d000
RBP: 000000000075c070 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 00007f554da526d4
R13: 00000000004c6855 R14: 00000000004dba68 R15: 00000000ffffffff