rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (1 GPs behind) idle=c46/1/0x4000000000000004 softirq=46930/46934 fqs=5250 (t=10502 jiffies g=67101 q=1392) NMI backtrace for cpu 0 CPU: 0 PID: 9556 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:__sanitizer_cov_trace_const_cmp1+0x1/0x20 kernel/kcov.c:175 Code: c3 0f 1f 84 00 00 00 00 00 55 48 89 f2 48 89 fe bf 06 00 00 00 48 89 e5 48 8b 4d 08 e8 18 ff ff ff 5d c3 66 0f 1f 44 00 00 55 <40> 0f b6 d6 40 0f b6 f7 bf 01 00 00 00 48 89 e5 48 8b 4d 08 e8 f6 RSP: 0000:ffff8880ae808f98 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000001 RBX: ffff888069d190b8 RCX: ffffffff85c66361 RDX: ffff888069d19150 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffff8880ae808ff8 R08: ffff8880a12b20c0 R09: 0000000000000000 R10: fffffbfff134af9f R11: ffff8880a12b20c0 R12: dffffc0000000000 R13: ffff888069d18dc0 R14: ffff888069d19158 R15: ffff888069d19150 dequeue_skb net/sched/sch_generic.c:263 [inline] qdisc_restart net/sched/sch_generic.c:366 [inline] __qdisc_run+0x1e5/0x1a00 net/sched/sch_generic.c:384 __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:4406 [inline] netdev_start_xmit include/linux/netdevice.h:4420 [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_resolve_output net/core/neighbour.c:1490 [inline] neigh_resolve_output+0x5a5/0x970 net/core/neighbour.c:1470 neigh_output include/net/neighbour.h:511 [inline] ip_finish_output2+0x8a5/0x2570 net/ipv4/ip_output.c:228 __ip_finish_output net/ipv4/ip_output.c:308 [inline] __ip_finish_output+0x5fc/0xb90 net/ipv4/ip_output.c:290 ip_finish_output+0x38/0x1f0 net/ipv4/ip_output.c:318 NF_HOOK_COND include/linux/netfilter.h:294 [inline] ip_output+0x21f/0x640 net/ipv4/ip_output.c:432 dst_output include/net/dst.h:436 [inline] ip_local_out+0xbb/0x190 net/ipv4/ip_output.c:125 igmpv3_sendpack+0x1b5/0x2c0 net/ipv4/igmp.c:426 igmpv3_send_cr net/ipv4/igmp.c:721 [inline] igmp_ifc_timer_expire+0x687/0xa00 net/ipv4/igmp.c:809 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: 0033:0x41debf Code: b6 0b 49 89 ca 44 89 c1 41 d3 e9 48 83 ff 08 74 0b 41 0f ba e1 04 0f 83 db 00 00 00 41 0f ba e1 00 73 b1 4c 8d 0c 37 4d 8b 09 <4d> 85 c9 74 a5 4c 39 c8 77 a0 49 39 d1 73 9b 4d 89 cb 49 29 f1 4d RSP: 002b:000000c420033e80 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13 RAX: 000000c420000000 RBX: 000000c41fdb232a RCX: 0000000000000002 RDX: 000000c430420000 RSI: 000000c4249b9ab0 RDI: 0000000000000000 RBP: 000000c420033f18 R08: 0000000000000002 R09: 0000000000be8240 R10: 0000000000000010 R11: 000000c4249b9ab0 R12: 0000000000000001 R13: 000000c42c3b4a20 R14: 0000000000000001 R15: 0000000000000000