rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-....: (1 GPs behind) idle=2b2/1/0x4000000000000002 softirq=44021/44022 fqs=5230 rcu: (t=10500 jiffies g=61469 q=4452) NMI backtrace for cpu 1 CPU: 1 PID: 21220 Comm: syz-executor2 Not tainted 4.19.0+ #95 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x244/0x39d lib/dump_stack.c:113 nmi_cpu_backtrace.cold.2+0x5c/0xa1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1e8/0x22a 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:162 [inline] rcu_dump_cpu_stacks+0x16f/0x1bc kernel/rcu/tree.c:1195 print_cpu_stall.cold.67+0x1f3/0x3c7 kernel/rcu/tree.c:1334 check_cpu_stall kernel/rcu/tree.c:1408 [inline] rcu_pending kernel/rcu/tree.c:2961 [inline] rcu_check_callbacks+0xf3b/0x13f0 kernel/rcu/tree.c:2506 update_process_times+0x2d/0x70 kernel/time/timer.c:1636 tick_sched_handle+0x9f/0x180 kernel/time/tick-sched.c:164 tick_sched_timer+0x45/0x130 kernel/time/tick-sched.c:1274 __run_hrtimer kernel/time/hrtimer.c:1398 [inline] __hrtimer_run_queues+0x41c/0x10d0 kernel/time/hrtimer.c:1460 hrtimer_interrupt+0x313/0x780 kernel/time/hrtimer.c:1518 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1034 [inline] smp_apic_timer_interrupt+0x1a1/0x760 arch/x86/kernel/apic/apic.c:1059 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:804 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:761 [inline] RIP: 0010:lock_release+0x51d/0xa00 kernel/locking/lockdep.c:3866 Code: 00 00 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 55 03 00 00 48 83 3d c2 3a f0 07 00 0f 84 15 02 00 00 48 8b bd e0 fe ff ff 57 9d <0f> 1f 44 00 00 48 b8 00 00 00 00 00 fc ff df 48 01 c3 48 c7 03 00 RSP: 0018:ffff88017e8e6f68 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: dffffc0000000000 RBX: 1ffff1002fd1cdf2 RCX: 1ffff1003b1bf5be RDX: 1ffffffff12a3f56 RSI: 1ffff1003b1bf5c5 RDI: 0000000000000286 RBP: ffff88017e8e7098 R08: 1ffff1002fd1cdf6 R09: ffffed002fb0f07f R10: 0000000000000002 R11: ffff88017d8783fb R12: ffff8801d8dfa580 R13: 0000000000000001 R14: ffff8801d8dfa580 R15: ffff88017e8e6fb0 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:174 [inline] _raw_spin_unlock_bh+0x1a/0x40 kernel/locking/spinlock.c:200 spin_unlock_bh include/linux/spinlock.h:374 [inline] some_qdisc_is_busy net/sched/sch_generic.c:1179 [inline] dev_deactivate_many+0x5c9/0xdd0 net/sched/sch_generic.c:1226 __dev_close_many+0x197/0x380 net/core/dev.c:1461 dev_close_many+0x2df/0x860 net/core/dev.c:1499 rollback_registered_many+0x543/0x1250 net/core/dev.c:7979 rollback_registered+0x1e9/0x420 net/core/dev.c:8044 unregister_netdevice_queue+0x321/0x5e0 net/core/dev.c:9088 unregister_netdevice include/linux/netdevice.h:2637 [inline] __tun_detach+0x11b8/0x15c0 drivers/net/tun.c:723 tun_detach drivers/net/tun.c:740 [inline] tun_chr_close+0xe3/0x180 drivers/net/tun.c:3376 __fput+0x385/0xa30 fs/file_table.c:278 ____fput+0x15/0x20 fs/file_table.c:309 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x318/0x380 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x411021 Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 34 19 00 00 c3 48 83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007fffa5242140 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000006 RCX: 0000000000411021 RDX: 0000000000000000 RSI: 0000000000732550 RDI: 0000000000000005 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 00007fffa5242060 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000001 R14: 000000000000011d R15: 0000000000000002