rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (10500 ticks this GP) idle=5f2/1/0x4000000000000000 softirq=129849/129849 fqs=143 
	(t=10502 jiffies g=258029 q=1204)
NMI backtrace for cpu 0
CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 5.8.0-rc6-syzkaller #0
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+0x18f/0x20d lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x194/0x1cf kernel/rcu/tree_stall.h:320
 print_cpu_stall kernel/rcu/tree_stall.h:553 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:627 [inline]
 rcu_pending kernel/rcu/tree.c:3489 [inline]
 rcu_sched_clock_irq.cold+0x5b3/0xccc kernel/rcu/tree.c:2504
 update_process_times+0x25/0x60 kernel/time/timer.c:1737
 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:176
 tick_sched_timer+0x108/0x290 kernel/time/tick-sched.c:1320
 __run_hrtimer kernel/time/hrtimer.c:1520 [inline]
 __hrtimer_run_queues+0x1d5/0xfc0 kernel/time/hrtimer.c:1584
 hrtimer_interrupt+0x32a/0x930 kernel/time/hrtimer.c:1646
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline]
 __sysvec_apic_timer_interrupt+0x142/0x5e0 arch/x86/kernel/apic/apic.c:1097
 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:711
 </IRQ>
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline]
 sysvec_apic_timer_interrupt+0xe0/0x120 arch/x86/kernel/apic/apic.c:1091
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:585
RIP: 0010:check_kcov_mode kernel/kcov.c:163 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x19/0x60 kernel/kcov.c:197
Code: 00 48 8b be b0 01 00 00 e8 b4 ff ff ff 31 c0 c3 90 65 48 8b 14 25 00 ff 01 00 65 8b 05 e0 41 8e 7e a9 00 01 ff 00 48 8b 34 24 <74> 0f f6 c4 01 74 35 8b 82 04 14 00 00 85 c0 74 2b 8b 82 e0 13 00
RSP: 0018:ffffc90000cfecd0 EFLAGS: 00000206
RAX: 0000000000000502 RBX: dffffc0000000000 RCX: ffffffff866129a0
RDX: ffff8880a95ea240 RSI: ffffffff86612b63 RDI: 0000000000000005
RBP: 00000000c0dfb89d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88805479c9c0
R13: ffff8880582b8780 R14: ffff8880a847e2d0 R15: ffff8880a847e000
 fq_dequeue+0x6b3/0x2010 net/sched/sch_fq.c:562
 dequeue_skb net/sched/sch_generic.c:263 [inline]
 qdisc_restart net/sched/sch_generic.c:366 [inline]
 __qdisc_run+0x1ac/0x1630 net/sched/sch_generic.c:384
 __dev_xmit_skb net/core/dev.c:3795 [inline]
 __dev_queue_xmit+0x1995/0x2d60 net/core/dev.c:4100
 neigh_resolve_output net/core/neighbour.c:1489 [inline]
 neigh_resolve_output+0x3fe/0x6a0 net/core/neighbour.c:1469
 neigh_output include/net/neighbour.h:509 [inline]
 ip6_finish_output2+0x8b6/0x17b0 net/ipv6/ip6_output.c:117
 __ip6_finish_output net/ipv6/ip6_output.c:143 [inline]
 __ip6_finish_output+0x447/0xab0 net/ipv6/ip6_output.c:128
 ip6_finish_output+0x34/0x1f0 net/ipv6/ip6_output.c:153
 NF_HOOK_COND include/linux/netfilter.h:296 [inline]
 ip6_output+0x1db/0x520 net/ipv6/ip6_output.c:176
 dst_output include/net/dst.h:443 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 NF_HOOK include/linux/netfilter.h:301 [inline]
 ip6_xmit+0x1258/0x1e80 net/ipv6/ip6_output.c:280
 sctp_v6_xmit+0x339/0x650 net/sctp/ipv6.c:217
 sctp_packet_transmit+0x20d7/0x3240 net/sctp/output.c:629
 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1475 [inline]
 sctp_side_effects net/sctp/sm_sideeffect.c:1185 [inline]
 sctp_do_sm+0x2b41/0x4d80 net/sctp/sm_sideeffect.c:1156
 sctp_endpoint_bh_rcv+0x3be/0x7e0 net/sctp/endpointola.c:395
 sctp_inq_push+0x1da/0x270 net/sctp/inqueue.c:80
 sctp_rcv+0xf4d/0x2d50 net/sctp/input.c:256
 sctp6_rcv+0x12/0x30 net/sctp/ipv6.c:1058
 ip6_protocol_deliver_rcu+0x2e8/0x1670 net/ipv6/ip6_input.c:433
 ip6_input_finish+0x7f/0x160 net/ipv6/ip6_input.c:474
 NF_HOOK include/linux/netfilter.h:307 [inline]
 NF_HOOK include/linux/netfilter.h:301 [inline]
 ip6_input+0x9c/0xd0 net/ipv6/ip6_input.c:483
 dst_input include/net/dst.h:449 [inline]
 ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 NF_HOOK include/linux/netfilter.h:301 [inline]
 ipv6_rcv+0x28e/0x3c0 net/ipv6/ip6_input.c:307
 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5281
 __netif_receive_skb+0x27/0x1c0 net/core/dev.c:5395
 process_backlog+0x28d/0x7f0 net/core/dev.c:6239
 napi_poll net/core/dev.c:6684 [inline]
 net_rx_action+0x4a1/0xe60 net/core/dev.c:6752
 __do_softirq+0x34c/0xa60 kernel/softirq.c:292
 run_ksoftirqd kernel/softirq.c:630 [inline]
 run_ksoftirqd+0x89/0x100 kernel/softirq.c:622
 smpboot_thread_fn+0x655/0x9e0 kernel/smpboot.c:165
 kthread+0x3b5/0x4a0 kernel/kthread.c:291
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293