rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (1 GPs behind) idle=8fe/1/0x4000000000000002 softirq=9765/9774 fqs=9 (t=10500 jiffies g=6657 q=36) rcu: rcu_preempt kthread starved for 10482 jiffies! g6657 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0 rcu: RCU grace-period kthread stack dump: rcu_preempt I28896 10 2 0x80004000 Call Trace: context_switch kernel/sched/core.c:3254 [inline] __schedule+0x877/0xc50 kernel/sched/core.c:3880 schedule+0x131/0x1e0 kernel/sched/core.c:3947 schedule_timeout+0x14f/0x240 kernel/time/timer.c:1807 rcu_gp_fqs_loop kernel/rcu/tree.c:1611 [inline] rcu_gp_kthread+0xef8/0x1790 kernel/rcu/tree.c:1768 kthread+0x332/0x350 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 NMI backtrace for cpu 1 CPU: 1 PID: 9129 Comm: syz-executor499 Not tainted 5.3.0-rc7+ #0 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+0x1d8/0x2f8 lib/dump_stack.c:113 nmi_cpu_backtrace+0xaf/0x1a0 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x174/0x290 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x10/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x15a/0x220 kernel/rcu/tree_stall.h:254 print_cpu_stall kernel/rcu/tree_stall.h:455 [inline] check_cpu_stall kernel/rcu/tree_stall.h:529 [inline] rcu_pending kernel/rcu/tree.c:2736 [inline] rcu_sched_clock_irq+0xb95/0x16d0 kernel/rcu/tree.c:2183 update_process_times+0x134/0x190 kernel/time/timer.c:1639 tick_sched_handle kernel/time/tick-sched.c:167 [inline] tick_sched_timer+0x263/0x420 kernel/time/tick-sched.c:1296 __run_hrtimer kernel/time/hrtimer.c:1389 [inline] __hrtimer_run_queues+0x403/0x850 kernel/time/hrtimer.c:1451 hrtimer_interrupt+0x38c/0xda0 kernel/time/hrtimer.c:1509 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1106 [inline] smp_apic_timer_interrupt+0x109/0x280 arch/x86/kernel/apic/apic.c:1131 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830 RIP: 0010:__list_del_entry_valid+0x36/0x100 lib/list_debug.c:43 Code: 89 fe 49 bc 00 00 00 00 00 fc ff df 48 83 c7 08 48 89 f8 48 c1 e8 03 42 80 3c 20 00 74 05 e8 71 c4 58 fe 4d 8b 7e 08 4c 89 f0 <48> c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 57 c4 58 fe 48 ba 00 RSP: 0018:ffff8880aeb094a8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: ffff8880982a5978 RBX: ffff8880982a5978 RCX: ffff888099a7c040 RDX: 0000000000000702 RSI: 0000000000000000 RDI: ffff8880982a5980 RBP: ffff8880aeb094c8 R08: ffffffff860c5d6a R09: 0000000000000000 R10: fffffbfff117be8d R11: 0000000000000000 R12: dffffc0000000000 R13: ffff8880982a5680 R14: ffff8880982a5978 R15: ffff8880982a5a10 __list_del_entry include/linux/list.h:131 [inline] list_move_tail include/linux/list.h:213 [inline] hhf_dequeue+0x487/0xaa0 net/sched/sch_hhf.c:439 dequeue_skb net/sched/sch_generic.c:258 [inline] qdisc_restart net/sched/sch_generic.c:361 [inline] __qdisc_run+0x217/0x1b30 net/sched/sch_generic.c:379 __dev_xmit_skb net/core/dev.c:3533 [inline] __dev_queue_xmit+0x1161/0x3020 net/core/dev.c:3838 dev_queue_xmit+0x17/0x20 net/core/dev.c:3902 br_dev_queue_push_xmit+0x551/0x650 net/bridge/br_forward.c:52 NF_HOOK include/linux/netfilter.h:305 [inline] br_forward_finish net/bridge/br_forward.c:65 [inline] NF_HOOK include/linux/netfilter.h:305 [inline] __br_forward+0x439/0x720 net/bridge/br_forward.c:109 deliver_clone net/bridge/br_forward.c:125 [inline] maybe_deliver net/bridge/br_forward.c:181 [inline] br_flood+0x52e/0x840 net/bridge/br_forward.c:223 br_dev_xmit+0xcb6/0x1100 net/bridge/br_device.c:96 __netdev_start_xmit include/linux/netdevice.h:4406 [inline] netdev_start_xmit include/linux/netdevice.h:4420 [inline] xmit_one net/core/dev.c:3280 [inline] dev_hard_start_xmit+0x1c1/0x3f0 net/core/dev.c:3296 __dev_queue_xmit+0x1e86/0x3020 net/core/dev.c:3869 dev_queue_xmit+0x17/0x20 net/core/dev.c:3902 neigh_hh_output include/net/neighbour.h:500 [inline] neigh_output include/net/neighbour.h:509 [inline] ip_finish_output2+0x145c/0x18d0 net/ipv4/ip_output.c:228 __ip_finish_output+0x801/0xa70 net/ipv4/ip_output.c:308 ip_finish_output+0x52/0x1e0 net/ipv4/ip_output.c:318 NF_HOOK_COND include/linux/netfilter.h:294 [inline] ip_output+0x1bc/0x280 net/ipv4/ip_output.c:432 dst_output include/net/dst.h:436 [inline] ip_local_out+0x105/0x140 net/ipv4/ip_output.c:125 igmpv3_sendpack+0x15a/0x230 net/ipv4/igmp.c:426 igmpv3_send_cr net/ipv4/igmp.c:721 [inline] igmp_ifc_timer_expire+0xb39/0xf60 net/ipv4/igmp.c:809 call_timer_fn+0x95/0x170 kernel/time/timer.c:1322 expire_timers kernel/time/timer.c:1366 [inline] __run_timers+0x79e/0x970 kernel/time/timer.c:1685 run_timer_softirq+0x4a/0x90 kernel/time/timer.c:1698 __do_softirq+0x333/0x7c4 arch/x86/include/asm/paravirt.h:778 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1082 do_softirq+0xfd/0x190 kernel/softirq.c:337 __local_bh_enable_ip+0x194/0x240 kernel/softirq.c:189 local_bh_enable+0x1f/0x30 include/linux/bottom_half.h:32 get_next_corpse net/netfilter/nf_conntrack_core.c:2014 [inline] nf_ct_iterate_cleanup+0x2fa/0x390 net/netfilter/nf_conntrack_core.c:2037 nf_ct_iterate_cleanup_net+0xf9/0x150 net/netfilter/nf_conntrack_core.c:2122 masq_device_event+0x9f/0xd0 net/netfilter/nf_nat_masquerade.c:88 notifier_call_chain kernel/notifier.c:95 [inline] __raw_notifier_call_chain kernel/notifier.c:396 [inline] raw_notifier_call_chain+0xec/0x190 kernel/notifier.c:403 call_netdevice_notifiers_info net/core/dev.c:1749 [inline] call_netdevice_notifiers_extack net/core/dev.c:1761 [inline] call_netdevice_notifiers net/core/dev.c:1775 [inline] dev_close_many+0x347/0x4d0 net/core/dev.c:1518 rollback_registered_many+0x454/0x1250 net/core/dev.c:8178 rollback_registered net/core/dev.c:8243 [inline] unregister_netdevice_queue+0x2ce/0x480 net/core/dev.c:9290 unregister_netdevice include/linux/netdevice.h:2631 [inline] __tun_detach+0x1101/0x1a90 drivers/net/tun.c:723 tun_detach drivers/net/tun.c:740 [inline] tun_chr_close+0xf1/0x130 drivers/net/tun.c:3442 __fput+0x2e4/0x740 fs/file_table.c:280 ____fput+0x15/0x20 fs/file_table.c:313 task_work_run+0x17e/0x1b0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x5e8/0x21a0 kernel/exit.c:879 do_group_exit+0x15c/0x2b0 kernel/exit.c:983 __do_sys_exit_group+0x17/0x20 kernel/exit.c:994 __se_sys_exit_group+0x14/0x20 kernel/exit.c:992 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:992 do_syscall_64+0xfe/0x140 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x440ce8 Code: Bad RIP value. RSP: 002b:00007fff2a475ee8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 0000000000440ce8 RDX: 0000000000000001 RSI: 000000000000003c RDI: 0000000000000001 RBP: 00000000004c7970 R08: 00000000000000e7 R09: ffffffffffffffd0 R10: 00000000bb1414ac R11: 0000000000000246 R12: 0000000000000001 R13: 00000000006da600 R14: 0000000000000000 R15: 0000000000000000