rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (1 GPs behind) idle=c3e/1/0x4000000000000002 softirq=217718/217719 fqs=5246 
rcu: 	 (t=10501 jiffies g=141489 q=524210)
NMI backtrace for cpu 1
CPU: 1 PID: 18205 Comm: syz-executor.2 Not tainted 4.19.109-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+0x188/0x20d lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1a6/0x1eb lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x170/0x1bb 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+0x634/0xddc kernel/rcu/tree.c:2682
 update_process_times+0x2a/0x70 kernel/time/timer.c:1638
 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:168
 tick_sched_timer+0x42/0x130 kernel/time/tick-sched.c:1278
 __run_hrtimer kernel/time/hrtimer.c:1401 [inline]
 __hrtimer_run_queues+0x2fc/0xd50 kernel/time/hrtimer.c:1463
 hrtimer_interrupt+0x312/0x770 kernel/time/hrtimer.c:1521
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1067 [inline]
 smp_apic_timer_interrupt+0x10c/0x550 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:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x91/0xe0 kernel/locking/spinlock.c:184
Code: 48 c7 c0 88 56 b2 88 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 37 48 83 3d 0e 4c 93 01 00 74 22 48 89 df 57 9d <0f> 1f 44 00 00 bf 01 00 00 00 e8 d0 8f 27 fa 65 8b 05 39 e3 e2 78
RSP: 0018:ffff8880ae707d48 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff1164ad1 RBX: 0000000000000286 RCX: 1ffff11009b8fdbc
RDX: dffffc0000000000 RSI: ffff88804dc7edc0 RDI: 0000000000000286
RBP: ffffffff8b805d48 R08: ffff88804dc7e540 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880896c7658
R13: dffffc0000000000 R14: 1ffff11015ce0fb0 R15: ffff88804468c780
 debug_object_deactivate lib/debugobjects.c:568 [inline]
 debug_object_deactivate+0x1e4/0x360 lib/debugobjects.c:529
 debug_rcu_head_unqueue kernel/rcu/rcu.h:205 [inline]
 rcu_do_batch kernel/rcu/tree.c:2583 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2897 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2864 [inline]
 rcu_process_callbacks+0xbed/0x17f0 kernel/rcu/tree.c:2881
 __do_softirq+0x26c/0x93c kernel/softirq.c:292
 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1091
 </IRQ>
 do_softirq.part.0+0x10f/0x160 kernel/softirq.c:336
 do_softirq kernel/softirq.c:328 [inline]
 __local_bh_enable_ip+0x20e/0x270 kernel/softirq.c:189
 local_bh_enable include/linux/bottom_half.h:32 [inline]
 get_next_corpse net/netfilter/nf_conntrack_core.c:1928 [inline]
 nf_ct_iterate_cleanup+0x217/0x4b0 net/netfilter/nf_conntrack_core.c:1951
 nf_ct_iterate_cleanup_net net/netfilter/nf_conntrack_core.c:2036 [inline]
 nf_ct_iterate_cleanup_net+0x113/0x170 net/netfilter/nf_conntrack_core.c:2021
 masq_device_event+0xd6/0x110 net/ipv4/netfilter/nf_nat_masquerade_ipv4.c:100
 notifier_call_chain+0xc0/0x230 kernel/notifier.c:93
 call_netdevice_notifiers net/core/dev.c:1766 [inline]
 dev_close_many+0x30d/0x650 net/core/dev.c:1518
 rollback_registered_many+0x2d6/0xc40 net/core/dev.c:8157
 rollback_registered+0xf2/0x1c0 net/core/dev.c:8222
 unregister_netdevice_queue net/core/dev.c:9275 [inline]
 unregister_netdevice_queue+0x1d7/0x2b0 net/core/dev.c:9268
 unregister_netdevice include/linux/netdevice.h:2614 [inline]
 __tun_detach+0xd86/0x1020 drivers/net/tun.c:737
 tun_detach drivers/net/tun.c:754 [inline]
 tun_chr_close+0xd9/0x180 drivers/net/tun.c:3261
 __fput+0x2cd/0x890 fs/file_table.c:278
 task_work_run+0x13f/0x1b0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0xbcd/0x2f30 kernel/exit.c:880
 do_group_exit+0x125/0x350 kernel/exit.c:983
 get_signal+0x3ec/0x1f90 kernel/signal.c:2583
 do_signal+0x8f/0x1710 arch/x86/kernel/signal.c:821
 exit_to_usermode_loop+0x22b/0x2b0 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+0x538/0x620 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c679
Code: Bad RIP value.
RSP: 002b:00007feacdb47c78 EFLAGS: 00000246 ORIG_RAX: 000000000000003b
RAX: fffffffffffffffc RBX: 00007feacdb486d4 RCX: 000000000045c679
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000180
RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000000a6 R14: 00000000004c31b1 R15: 000000000076bf0c