rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (1 GPs behind) idle=4ee/1/0x4000000000000002 softirq=19446/19449 fqs=595 
	(t=10500 jiffies g=27689 q=116)
rcu: rcu_preempt kthread starved for 9302 jiffies! g27689 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
rcu: RCU grace-period kthread stack dump:
rcu_preempt     I29032    10      2 0x80004000
Call Trace:
 context_switch kernel/sched/core.c:3265 [inline]
 __schedule+0x76e/0x17a0 kernel/sched/core.c:3937
 schedule+0xd9/0x260 kernel/sched/core.c:4004
 schedule_timeout+0x486/0xc50 kernel/time/timer.c:1893
 rcu_gp_fqs_loop kernel/rcu/tree.c:1639 [inline]
 rcu_gp_kthread+0x9b2/0x18d0 kernel/rcu/tree.c:1799
 kthread+0x361/0x430 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
NMI backtrace for cpu 1
CPU: 1 PID: 12905 Comm: syz-executor.5 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
 </IRQ>
RIP: 0010:__list_del_entry_valid+0x4b/0xf5 lib/list_debug.c:45
Code: 54 80 3c 02 00 0f 85 a1 00 00 00 4c 89 f2 4d 8b 66 08 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 9d 00 00 00 <48> b8 00 01 00 00 00 00 ad de 4d 8b 2e 49 39 c5 0f 84 e1 00 00 00
RSP: 0018:ffff8880566d6dd0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: dffffc0000000000 RBX: ffff88809405aaf8 RCX: ffffc90010dd8000
RDX: 1ffff1101280b55f RSI: ffffffff85cb6e86 RDI: ffff88809405ab00
RBP: ffff8880566d6de8 R08: ffff8880a380c480 R09: fffffbfff14ed341
R10: ffff8880a380cde8 R11: ffff8880a380c480 R12: ffff88809405ab90
R13: ffff88809405a800 R14: ffff88809405aaf8 R15: 0000000000000000
 __list_del_entry include/linux/list.h:131 [inline]
 list_move_tail include/linux/list.h:213 [inline]
 hhf_dequeue+0x5c5/0xa20 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]
 ip_finish_output2+0x1752/0x2590 net/ipv4/ip_output.c:228
 ip_do_fragment+0x17fd/0x1cf0 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/0xbc0 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+0x292/0xf70 net/ipv4/ip_output.c:417
 dst_output include/net/dst.h:436 [inline]
 ip_local_out+0xbb/0x1b0 net/ipv4/ip_output.c:125
 ip_send_skb+0x42/0xf0 net/ipv4/ip_output.c:1554
 ip_push_pending_frames+0x64/0x80 net/ipv4/ip_output.c:1574
 raw_sendmsg+0x1390/0x2f50 net/ipv4/raw.c:672
 inet_sendmsg+0x9e/0xe0 net/ipv4/af_inet.c:807
 sock_sendmsg_nosec net/socket.c:637 [inline]
 sock_sendmsg+0xd7/0x130 net/socket.c:657
 kernel_sendmsg+0x44/0x50 net/socket.c:677
 sock_no_sendpage+0x116/0x150 net/core/sock.c:2733
 inet_sendpage+0x10f/0x150 net/ipv4/af_inet.c:822
 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+0xfa/0x760 arch/x86/entry/common.c:290
 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:00007f7f47d75c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000113
RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 00000000004598e9
RDX: 0000000000000005 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 000000000075c070 R08: 0000000000010005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f7f47d766d4
R13: 00000000004c90ca R14: 00000000004df570 R15: 00000000ffffffff