------------[ cut here ]------------
WARNING: CPU: 1 PID: 3464 at net/ipv6/ip6_fib.c:1477 fib6_del+0x947/0xca0 net/ipv6/ip6_fib.c:1477
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 3464 Comm: kworker/u4:4 Not tainted 4.13.0-rc7+ #60
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:16 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:52
 panic+0x1e4/0x417 kernel/panic.c:180
 __warn+0x1c4/0x1d9 kernel/panic.c:541
 report_bug+0x211/0x2d0 lib/bug.c:183
 fixup_bug+0x40/0x90 arch/x86/kernel/traps.c:190
 do_trap_no_signal arch/x86/kernel/traps.c:224 [inline]
 do_trap+0x260/0x390 arch/x86/kernel/traps.c:273
 do_error_trap+0x120/0x390 arch/x86/kernel/traps.c:310
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:323
 invalid_op+0x1e/0x30 arch/x86/entry/entry_64.S:846
RIP: 0010:fib6_del+0x947/0xca0 net/ipv6/ip6_fib.c:1477
RSP: 0018:ffff8801db3074d8 EFLAGS: 00010206
RAX: ffff8801c943a000 RBX: ffff8801ccfc4a80 RCX: 0000000000000000
RDX: 0000000000000100 RSI: ffff8801db307650 RDI: ffff8801ccfc4ae4
RBP: ffff8801db3075f0 R08: ffffffff86df1658 R09: ffff8801db306f38
R10: ffff8801db3074b8 R11: 1ffff1003928765b R12: dffffc0000000000
R13: ffff8801db307650 R14: ffff8801a0fce080 R15: 1ffff1003b660ea5
 __ip6_del_rt+0xc7/0x120 net/ipv6/route.c:2136
 ip6_del_rt+0x132/0x1a0 net/ipv6/route.c:2149
 ip6_link_failure+0x244/0x380 net/ipv6/route.c:1359
 dst_link_failure include/net/dst.h:454 [inline]
 ndisc_error_report+0xae/0x180 net/ipv6/ndisc.c:682
 neigh_invalidate+0x225/0x530 net/core/neighbour.c:883
 neigh_timer_handler+0x883/0xca0 net/core/neighbour.c:969
 call_timer_fn+0x233/0x830 kernel/time/timer.c:1281
 expire_timers kernel/time/timer.c:1320 [inline]
 __run_timers+0x7fd/0xb90 kernel/time/timer.c:1620
 run_timer_softirq+0x4c/0xb0 kernel/time/timer.c:1646
 __do_softirq+0x2f5/0xba3 kernel/softirq.c:284
 invoke_softirq kernel/softirq.c:364 [inline]
 irq_exit+0x1cc/0x200 kernel/softirq.c:405
 exiting_irq arch/x86/include/asm/apic.h:638 [inline]
 smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:1044
 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:702
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:814 [inline]
RIP: 0010:lock_release+0x505/0xa40 kernel/locking/lockdep.c:3877
RSP: 0018:ffff8801c98aef88 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff10
RAX: dffffc0000000000 RBX: ffff8801c943a000 RCX: 1ffff1003928750e
RDX: 1ffffffff0b59371 RSI: 0000000000000004 RDI: 0000000000000286
RBP: ffff8801c98af0b8 R08: 0000000000000001 R09: 1ffff10039315dfa
R10: ffff8801c98aef98 R11: 0000000000000003 R12: 1505ca00f65c59b7
R13: ffff8801c943a000 R14: ffff8801c98aefd0 R15: 1ffff10039315df6
 </IRQ>
 rcu_lock_release include/linux/rcupdate.h:244 [inline]
 rcu_read_unlock include/linux/rcupdate.h:665 [inline]
 inet_twsk_purge+0x501/0x770 net/ipv4/inet_timewait_sock.c:302
 dccp_v6_exit_batch+0x1a/0x20 net/dccp/ipv6.c:1089
 ops_exit_list.isra.6+0x100/0x150 net/core/net_namespace.c:145
 cleanup_net+0x5c7/0xb50 net/core/net_namespace.c:483
 process_one_work+0xbf3/0x1bc0 kernel/workqueue.c:2097
 worker_thread+0x223/0x1860 kernel/workqueue.c:2231
 kthread+0x35e/0x430 kernel/kthread.c:231
 ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:425
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..