rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-....: (1 GPs behind) idle=28a/1/0x4000000000000004 softirq=14332/14334 fqs=5250 (t=10502 jiffies g=13653 q=1883) NMI backtrace for cpu 1 CPU: 1 PID: 8894 Comm: syz-fuzzer 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+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x23b/0x28b 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+0x183/0x1cf 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.cold+0x4dd/0xc13 kernel/rcu/tree.c:2183 update_process_times+0x32/0x80 kernel/time/timer.c:1639 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:167 tick_sched_timer+0x53/0x140 kernel/time/tick-sched.c:1296 __run_hrtimer kernel/time/hrtimer.c:1389 [inline] __hrtimer_run_queues+0x364/0xe40 kernel/time/hrtimer.c:1451 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1106 [inline] smp_apic_timer_interrupt+0x160/0x610 arch/x86/kernel/apic/apic.c:1131 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830 RIP: 0010:__list_del_entry include/linux/list.h:134 [inline] RIP: 0010:__list_del_entry include/linux/list.h:129 [inline] RIP: 0010:list_move_tail include/linux/list.h:213 [inline] RIP: 0010:hhf_dequeue+0x600/0xa20 net/sched/sch_hhf.c:439 Code: e8 75 94 aa fb 48 89 d8 48 c1 e8 03 42 80 3c 20 00 0f 85 f3 03 00 00 48 8d 7b 08 4c 8b 3b 48 89 fa 48 c1 ea 03 42 80 3c 22 00 <0f> 85 d0 03 00 00 49 8d 7f 08 4c 8b 73 08 48 89 fa 48 c1 ea 03 42 RSP: 0000:ffff8880ae908e78 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 1ffff11011ccbcef RBX: ffff88808e65e778 RCX: ffffffff85c7e0d1 RDX: 1ffff11011ccbcf0 RSI: ffffffff85c7e0db RDI: ffff88808e65e780 RBP: ffff8880ae908ec8 R08: ffff8880a4cda2c0 R09: fffffbfff14e9755 R10: ffff8880a4cdac68 R11: ffff8880a4cda2c0 R12: dffffc0000000000 R13: ffff88808e65e480 R14: 0000000000000001 R15: ffff88808e65e810 dequeue_skb net/sched/sch_generic.c:258 [inline] qdisc_restart net/sched/sch_generic.c:361 [inline] __qdisc_run+0x1e7/0x19d0 net/sched/sch_generic.c:379 __dev_xmit_skb net/core/dev.c:3533 [inline] __dev_queue_xmit+0x16f1/0x3650 net/core/dev.c:3838 dev_queue_xmit+0x18/0x20 net/core/dev.c:3902 br_dev_queue_push_xmit+0x3f3/0x5c0 net/bridge/br_forward.c:52 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] br_forward_finish+0xfa/0x400 net/bridge/br_forward.c:65 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] __br_forward+0x641/0xb00 net/bridge/br_forward.c:109 deliver_clone+0x61/0xc0 net/bridge/br_forward.c:125 maybe_deliver+0x2c7/0x390 net/bridge/br_forward.c:181 br_flood+0x13a/0x3d0 net/bridge/br_forward.c:223 br_dev_xmit+0x98c/0x15a0 net/bridge/br_device.c:100 __netdev_start_xmit include/linux/netdevice.h:4419 [inline] netdev_start_xmit include/linux/netdevice.h:4433 [inline] xmit_one net/core/dev.c:3280 [inline] dev_hard_start_xmit+0x1a3/0x9c0 net/core/dev.c:3296 __dev_queue_xmit+0x2b15/0x3650 net/core/dev.c:3869 dev_queue_xmit+0x18/0x20 net/core/dev.c:3902 neigh_hh_output include/net/neighbour.h:500 [inline] neigh_output include/net/neighbour.h:509 [inline] ip6_finish_output2+0xf58/0x2520 net/ipv6/ip6_output.c:116 __ip6_finish_output+0x444/0xa50 net/ipv6/ip6_output.c:142 ip6_finish_output+0x38/0x1f0 net/ipv6/ip6_output.c:152 NF_HOOK_COND include/linux/netfilter.h:294 [inline] ip6_output+0x235/0x7c0 net/ipv6/ip6_output.c:175 dst_output include/net/dst.h:436 [inline] NF_HOOK include/linux/netfilter.h:305 [inline] ndisc_send_skb+0xf29/0x1450 net/ipv6/ndisc.c:505 ndisc_send_rs+0x134/0x6d0 net/ipv6/ndisc.c:699 addrconf_rs_timer+0x30f/0x680 net/ipv6/addrconf.c:3879 call_timer_fn+0x1ac/0x780 kernel/time/timer.c:1322 expire_timers kernel/time/timer.c:1366 [inline] __run_timers kernel/time/timer.c:1685 [inline] __run_timers kernel/time/timer.c:1653 [inline] run_timer_softirq+0x697/0x17a0 kernel/time/timer.c:1698 __do_softirq+0x262/0x98c kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x19b/0x1e0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:537 [inline] smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1133 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830 RIP: 0033:0x40cd0f Code: 24 a0 00 00 00 48 8b 6c 24 70 48 83 c4 78 c3 4c 8b 8c 24 80 00 00 00 45 0f b7 51 54 49 89 d3 4f 8d 54 13 f8 41 84 01 4d 8b 12 <4d> 85 d2 74 10 4c 89 d2 48 89 54 24 60 45 31 c9 e9 8c fe ff ff 4c RSP: 002b:000000c42c5d8e68 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff13 RAX: 00000000000000ea RBX: 000000c4297e4a50 RCX: 000000c4280f4840 RDX: 000000c4280f4840 RSI: ea87b99ff6b522fa RDI: 000000c4280f4848 RBP: 000000c42c5d8ed8 R08: 000000c4280f48c8 R09: 0000000000839620 R10: 0000000000000000 R11: 000000c4280f4840 R12: 000000c4280f4848 R13: 000000c4280f4840 R14: 0000000000000032 R15: 0000000000000002