rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (10500 ticks this GP) idle=41a/1/0x4000000000000002 softirq=18729/18729 fqs=5250 
rcu: 	 (t=10502 jiffies g=18913 q=1376)
NMI backtrace for cpu 0
CPU: 0 PID: 11605 Comm: syz-executor.4 Not tainted 5.1.0-rc5+ #172
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+0x63/0xa4 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1be/0x236 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.c:1223
 print_cpu_stall kernel/rcu/tree.c:1360 [inline]
 check_cpu_stall kernel/rcu/tree.c:1434 [inline]
 rcu_pending kernel/rcu/tree.c:3103 [inline]
 rcu_sched_clock_irq.cold+0x500/0xa4a kernel/rcu/tree.c:2544
 update_process_times+0x32/0x80 kernel/time/timer.c:1635
 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:161
 tick_sched_timer+0x47/0x130 kernel/time/tick-sched.c:1271
 __run_hrtimer kernel/time/hrtimer.c:1389 [inline]
 __hrtimer_run_queues+0x33e/0xde0 kernel/time/hrtimer.c:1451
 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1035 [inline]
 smp_apic_timer_interrupt+0x120/0x570 arch/x86/kernel/apic/apic.c:1060
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
 </IRQ>
RIP: 0010:cpu_relax arch/x86/include/asm/processor.h:666 [inline]
RIP: 0010:virt_spin_lock arch/x86/include/asm/qspinlock.h:84 [inline]
RIP: 0010:native_queued_spin_lock_slowpath+0x132/0x9f0 kernel/locking/qspinlock.c:334
Code: 00 00 00 48 8b 45 d0 65 48 33 04 25 28 00 00 00 0f 85 37 07 00 00 48 81 c4 98 00 00 00 5b 41 5c 41 5d 41 5e 41 5f 5d c3 f3 90 <e9> 73 ff ff ff 8b 45 98 4c 8d 65 d8 3d 00 01 00 00 0f 84 e5 00 00
RSP: 0018:ffff888066e7f048 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000000 RBX: ffffe8ffffc73c80 RCX: ffffffff815834c7
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffe8ffffc73c80
RBP: ffff888066e7f108 R08: 1ffffd1ffff8e790 R09: fffff91ffff8e791
R10: fffff91ffff8e790 R11: ffffe8ffffc73c83 R12: 0000000000000001
R13: 0000000000000003 R14: fffff91ffff8e790 R15: 000000000000000e
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:654 [inline]
 queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:50 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:90 [inline]
 do_raw_spin_lock+0x20e/0x2e0 kernel/locking/spinlock_debug.c:113
 __raw_spin_lock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_lock+0x37/0x40 kernel/locking/spinlock.c:144
 spin_lock include/linux/spinlock.h:329 [inline]
 nf_ct_add_to_unconfirmed_list net/netfilter/nf_conntrack_core.c:487 [inline]
 init_conntrack.isra.0+0xa07/0x1170 net/netfilter/nf_conntrack_core.c:1478
 resolve_normal_ct net/netfilter/nf_conntrack_core.c:1519 [inline]
 nf_conntrack_in+0xd93/0x1410 net/netfilter/nf_conntrack_core.c:1679
 ipv6_conntrack_local+0x1e/0x30 net/netfilter/nf_conntrack_proto.c:194
 nf_hook_entry_hookfn include/linux/netfilter.h:119 [inline]
 nf_hook_slow+0xbf/0x1f0 net/netfilter/core.c:511
 nf_hook include/linux/netfilter.h:244 [inline]
 __ip6_local_out+0x45e/0x8e0 net/ipv6/output_core.c:164
 ip6_local_out+0x2d/0x1b0 net/ipv6/output_core.c:174
 ip6_send_skb+0xbb/0x350 net/ipv6/ip6_output.c:1735
 udp_v6_send_skb.isra.0+0x839/0x14f0 net/ipv6/udp.c:1181
 udp_v6_push_pending_frames+0x295/0x3b0 net/ipv6/udp.c:1214
 udpv6_sendmsg+0x1b18/0x28d0 net/ipv6/udp.c:1505
 inet_sendmsg+0x147/0x5d0 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg+0xdd/0x130 net/socket.c:661
 sock_write_iter+0x27c/0x3e0 net/socket.c:988
 call_write_iter include/linux/fs.h:1866 [inline]
 new_sync_write+0x4c7/0x760 fs/read_write.c:474
 __vfs_write+0xe4/0x110 fs/read_write.c:487
 vfs_write+0x20c/0x580 fs/read_write.c:549
 ksys_write+0x14f/0x2d0 fs/read_write.c:599
 __do_sys_write fs/read_write.c:611 [inline]
 __se_sys_write fs/read_write.c:608 [inline]
 __x64_sys_write+0x73/0xb0 fs/read_write.c:608
 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x458c29
Code: ad b8 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 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f7801434c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458c29
RDX: 000000000000ffdc RSI: 0000000020000200 RDI: 0000000000000003
RBP: 000000000073bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f78014356d4
R13: 00000000004c8649 R14: 00000000004ded98 R15: 00000000ffffffff