rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (10499 ticks this GP) idle=346/1/0x4000000000000002 softirq=247219/247219 fqs=5234 
	(t=10500 jiffies g=369253 q=3204)
NMI backtrace for cpu 0
CPU: 0 PID: 5324 Comm: syz-executor.4 Not tainted 5.3.0-rc8+ #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+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:1110 [inline]
 smp_apic_timer_interrupt+0x160/0x610 arch/x86/kernel/apic/apic.c:1135
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830
 </IRQ>
RIP: 0010:__read_once_size include/linux/compiler.h:199 [inline]
RIP: 0010:list_empty include/linux/list.h:268 [inline]
RIP: 0010:hhf_dequeue+0x4c/0xa20 net/sched/sch_hhf.c:427
Code: fb 49 8d 85 80 03 00 00 48 89 45 d0 48 c1 e8 03 4c 01 e0 48 89 45 c0 49 8d 85 90 03 00 00 48 89 45 c8 48 c1 e8 03 48 89 45 b8 <e8> 2f 0a ac fb 48 8b 45 c0 80 38 00 0f 85 a8 07 00 00 48 8b 75 d0
RSP: 0018:ffff888210a0e9d8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 1ffff110152173d2 RBX: ffff8880a90b9df8 RCX: ffffc9000e7a1000
RDX: 0000000000040000 RSI: ffffffff85c6710b RDI: ffff8880a90b9e00
RBP: ffff888210a0ea28 R08: ffff8880688e0680 R09: 0000000000000000
R10: fffffbfff134afaf R11: ffff8880688e0680 R12: dffffc0000000000
R13: ffff8880a90b9b00 R14: ffff8880a90b9e98 R15: ffff8880a90b9e90
 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: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_do_fragment+0x174f/0x1c60 net/ipv4/ip_output.c:849
 ip_fragment.constprop.0+0x176/0x240 net/ipv4/ip_output.c:575
 __ip_finish_output net/ipv4/ip_output.c:306 [inline]
 __ip_finish_output+0x4bd/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_mc_output+0x292/0xf40 net/ipv4/ip_output.c:417
 dst_output include/net/dst.h:436 [inline]
 ip_local_out+0xbb/0x190 net/ipv4/ip_output.c:125
 ip_send_skb+0x42/0xf0 net/ipv4/ip_output.c:1554
 udp_send_skb.isra.0+0x6b2/0x1160 net/ipv4/udp.c:887
 udp_push_pending_frames+0x5c/0xf0 net/ipv4/udp.c:915
 udp_sendpage+0x30c/0x480 net/ipv4/udp.c:1286
 inet_sendpage+0xdb/0x150 net/ipv4/af_inet.c:821
 kernel_sendpage+0x92/0xf0 net/socket.c:3682
 sock_sendpage+0x8b/0xc0 net/socket.c:935
 pipe_to_sendpage+0x296/0x360 fs/splice.c:449
 splice_from_pipe_feed fs/splice.c:500 [inline]
 __splice_from_pipe+0x397/0x7d0 fs/splice.c:624
 splice_from_pipe+0x108/0x170 fs/splice.c:659
 generic_splice_sendpage+0x3c/0x50 fs/splice.c:829
 do_splice_from fs/splice.c:848 [inline]
 do_splice+0x708/0x1410 fs/splice.c:1155
 __do_sys_splice fs/splice.c:1425 [inline]
 __se_sys_splice fs/splice.c:1405 [inline]
 __x64_sys_splice+0x2c6/0x330 fs/splice.c:1405
 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4598e9
Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f07855bdc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000113
RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 00000000004598e9
RDX: 0000000000000005 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 000000000075bf20 R08: 0000000000010005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f07855be6d4
R13: 00000000004c90ca R14: 00000000004df570 R15: 00000000ffffffff