rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (1 GPs behind) idle=566/1/0x4000000000000004 softirq=29331/29333 fqs=5207 
	(t=10500 jiffies g=44321 q=900)
NMI backtrace for cpu 1
CPU: 1 PID: 8825 Comm: syz-fuzzer Not tainted 5.3.0-rc6-next-20190830 #75
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+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:2795 [inline]
 rcu_sched_clock_irq.cold+0x4fd/0xc12 kernel/rcu/tree.c:2244
 update_process_times+0x2d/0x70 kernel/time/timer.c:1724
 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:167
 tick_sched_timer+0x53/0x140 kernel/time/tick-sched.c:1299
 __run_hrtimer kernel/time/hrtimer.c:1504 [inline]
 __hrtimer_run_queues+0x364/0xe40 kernel/time/hrtimer.c:1566
 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1628
 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+0x11/0x20 kernel/kcov.c:175
Code: 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 fe ff ff 5d c3 0f 1f 40 00 55 0f b7 d6 0f b7 f7
RSP: 0000:ffff8880ae909508 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000001 RBX: ffff8880a4eecaf8 RCX: ffffffff85cb69b9
RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000001
RBP: ffff8880ae909508 R08: ffff888099eb2500 R09: fffffbfff14ed341
R10: ffff888099eb2e68 R11: ffff888099eb2500 R12: dffffc0000000000
R13: ffff8880a4eec800 R14: 0000000000000001 R15: 0000000000000000
 __list_del_entry include/linux/list.h:131 [inline]
 list_move_tail include/linux/list.h:213 [inline]
 hhf_dequeue+0x5d1/0xa20 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+0x1e7/0x19d0 net/sched/sch_generic.c:379
 __dev_xmit_skb net/core/dev.c:3533 [inline]
 __dev_queue_xmit+0x16f1/0x37c0 net/core/dev.c:3838
 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+0xf58/0x2550 net/ipv6/ip6_output.c:116
 __ip6_finish_output+0x444/0xaa0 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+0x235/0x7f0 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+0xf29/0x14a0 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:1404
 expire_timers kernel/time/timer.c:1449 [inline]
 __run_timers kernel/time/timer.c:1771 [inline]
 __run_timers kernel/time/timer.c:1738 [inline]
 run_timer_softirq+0x6c0/0x17f0 kernel/time/timer.c:1784
 __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:536 [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
 </IRQ>
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:000000c42014be68 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13
RAX: 000000c420000000 RBX: 000000c41f6a5684 RCX: 0000000000000000
RDX: 000000c442160000 RSI: 000000c432b52f60 RDI: 0000000000000000
RBP: 000000c42014bf00 R08: 0000000000000000 R09: 0000000000c1af60
R10: 0000000000000030 R11: 000000c434af0d80 R12: 0000000000000001
R13: 000000c43f6943c0 R14: 0000000000000001 R15: 0000000000000000