------------[ cut here ]------------
WARNING: CPU: 0 PID: 4012 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: 0 PID: 4012 Comm: syz-executor4 Not tainted 4.13.0-rc7+ #59
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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:ffff8801db207398 EFLAGS: 00010206
RAX: ffff8801d264e740 RBX: ffff8801ce4b9540 RCX: 0000000000000000
RDX: 0000000000000100 RSI: ffff8801db207510 RDI: ffff8801ce4b95a4
RBP: ffff8801db2074b0 R08: ffffffff86df1658 R09: 0000000000000002
R10: ffff8801db207378 R11: 1ffff1003a4c9f43 R12: dffffc0000000000
R13: ffff8801db207510 R14: ffff8801d758c3c0 R15: 1ffff1003b640e7d
 __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_trace_apic_timer_interrupt+0x139/0x6a0 arch/x86/kernel/apic/apic.c:1065
 trace_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:kmem_cache_free+0x170/0x280 mm/slab.c:3764
RSP: 0018:ffff8801c2817588 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff10
RAX: 0000000000000007 RBX: ffff8801c5e49720 RCX: 0000000000000006
RDX: 0000000000000000 RSI: 1ffff1003a4c9dfc RDI: 0000000000000286
RBP: ffff8801c28175a8 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801dac73e00
R13: 0000000000000286 R14: ffffffff8199522d R15: ffff8801c5e49738
 </IRQ>
 anon_vma_chain_free mm/rmap.c:132 [inline]
 unlink_anon_vmas+0x20d/0x9f0 mm/rmap.c:399
 free_pgtables+0x21e/0x330 mm/memory.c:633
 exit_mmap+0x246/0x470 mm/mmap.c:2996
 __mmput kernel/fork.c:904 [inline]
 mmput+0x223/0x6e0 kernel/fork.c:926
 exit_mm kernel/exit.c:544 [inline]
 do_exit+0x989/0x1b10 kernel/exit.c:852
 do_group_exit+0x149/0x400 kernel/exit.c:969
 SYSC_exit_group kernel/exit.c:980 [inline]
 SyS_exit_group+0x1d/0x20 kernel/exit.c:978
 entry_SYSCALL_64_fastpath+0x1f/0xbe
RIP: 0033:0x4512e9
RSP: 002b:0000000020c6ca48 EFLAGS: 00000206 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 000000000000000b RCX: 00000000004512e9
RDX: 00000000004512e9 RSI: 0000000020c6ca80 RDI: 000000000000000b
RBP: 0000000000000086 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020ef1ffe R11: 0000000000000206 R12: 00000000004b65e0
R13: 00000000ffffffff R14: 0000000000000000 R15: 0000000020c6d000
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..