[<ffffffff838ac5c5>] entry_SYSCALL_64_fastpath+0x23/0xc6
------------[ cut here ]------------
WARNING: CPU: 1 PID: 10103 at net/ipv6/ip6_fib.c:1475 fib6_del+0x7a3/0xa30 net/ipv6/ip6_fib.c:1475
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 10103 Comm: syz-executor7 Not tainted 4.9.52-gc30c69c #54
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801db307998 ffffffff81d93149 ffffffff83a46b40 ffff8801db307a70
 ffffffff83f47f00 ffffffff8346cd23 0000000000000009 ffff8801db307a60
 ffffffff8142e771 0000000041b58ab3 ffffffff84185358 ffffffff8142e5b5
Call Trace:
 <IRQ> [   62.375573]  [<ffffffff81d93149>] __dump_stack lib/dump_stack.c:15 [inline]
 <IRQ> [   62.375573]  [<ffffffff81d93149>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff8142e771>] panic+0x1bc/0x3a8 kernel/panic.c:179
 [<ffffffff81131ed4>] __warn+0x1c4/0x1e0 kernel/panic.c:542
 [<ffffffff8113213c>] warn_slowpath_null+0x2c/0x40 kernel/panic.c:585
 [<ffffffff8346cd23>] fib6_del+0x7a3/0xa30 net/ipv6/ip6_fib.c:1475
 [<ffffffff8344ce50>] __ip6_del_rt+0x100/0x160 net/ipv6/route.c:2140
 [<ffffffff8346009a>] ip6_del_rt+0xca/0x110 net/ipv6/route.c:2153
 [<ffffffff83461513>] ip6_link_failure+0x243/0x3e0 net/ipv6/route.c:1339
 [<ffffffff83474f8e>] dst_link_failure include/net/dst.h:490 [inline]
 [<ffffffff83474f8e>] ndisc_error_report+0xae/0x190 net/ipv6/ndisc.c:671
 [<ffffffff82f5d275>] neigh_invalidate+0x225/0x530 net/core/neighbour.c:847
 [<ffffffff82f62c67>] neigh_timer_handler+0x597/0xa10 net/core/neighbour.c:933
 [<ffffffff812a5044>] call_timer_fn+0x164/0x700 kernel/time/timer.c:1321
 [<ffffffff812a5f33>] expire_timers kernel/time/timer.c:1361 [inline]
 [<ffffffff812a5f33>] __run_timers kernel/time/timer.c:1660 [inline]
 [<ffffffff812a5f33>] run_timer_softirq+0x693/0x1640 kernel/time/timer.c:1686
 [<ffffffff838af45d>] __do_softirq+0x22d/0x964 kernel/softirq.c:284
 [<ffffffff81147985>] invoke_softirq kernel/softirq.c:364 [inline]
 [<ffffffff81147985>] irq_exit+0x165/0x190 kernel/softirq.c:405
 [<ffffffff838aecfb>] exiting_irq arch/x86/include/asm/apic.h:659 [inline]
 [<ffffffff838aecfb>] smp_apic_timer_interrupt+0x7b/0xa0 arch/x86/kernel/apic/apic.c:960
 [<ffffffff838add9c>] apic_timer_interrupt+0x8c/0xa0 arch/x86/entry/entry_64.S:709
 <EOI> [   62.596061]  [<ffffffff81da644f>] ? __rb_erase_augmented include/linux/rbtree_augmented.h:185 [inline]
 <EOI> [   62.596061]  [<ffffffff81da644f>] ? rb_erase+0x8f/0x1b60 lib/rbtree.c:427
 [<ffffffff816ee94c>] kernfs_unlink_sibling+0xbc/0x150 fs/kernfs/dir.c:386
 [<ffffffff816f0936>] __kernfs_remove+0x2a6/0x820 fs/kernfs/dir.c:1228
 [<ffffffff816f3144>] kernfs_remove_by_name_ns+0x54/0xc0 fs/kernfs/dir.c:1414
 [<ffffffff816fa76b>] kernfs_remove_by_name include/linux/kernfs.h:494 [inline]
 [<ffffffff816fa76b>] remove_files.isra.1+0x7b/0x190 fs/sysfs/group.c:29
 [<ffffffff816fb286>] sysfs_remove_group+0xb6/0x1c0 fs/sysfs/group.c:245
 [<ffffffff816fb533>] sysfs_remove_groups+0x63/0xb0 fs/sysfs/group.c:269
 [<ffffffff824419eb>] device_remove_groups drivers/base/core.c:466 [inline]
 [<ffffffff824419eb>] device_remove_attrs+0x11b/0x160 drivers/base/core.c:523
 [<ffffffff824431fa>] device_del+0x3ea/0x8a0 drivers/base/core.c:1283
 [<ffffffff82f9e736>] netdev_unregister_kobject+0xe6/0x110 net/core/net-sysfs.c:1534
 [<ffffffff82f282ef>] rollback_registered_many+0x56f/0x960 net/core/dev.c:6825
 [<ffffffff82f28761>] rollback_registered+0x81/0xb0 net/core/dev.c:6843
 [<ffffffff82f2b551>] unregister_netdevice_queue+0x81/0x140 net/core/dev.c:7830
 [<ffffffff8270ac6c>] unregister_netdevice include/linux/netdevice.h:2458 [inline]
 [<ffffffff8270ac6c>] __tun_detach+0xa2c/0xc20 drivers/net/tun.c:567
 [<ffffffff8270aea4>] tun_detach drivers/net/tun.c:578 [inline]
 [<ffffffff8270aea4>] tun_chr_close+0x44/0x60 drivers/net/tun.c:2370
 [<ffffffff81573fdc>] __fput+0x28c/0x6e0 fs/file_table.c:208
 [<ffffffff815744b5>] ____fput+0x15/0x20 fs/file_table.c:244
 [<ffffffff81195d75>] task_work_run+0x115/0x190 kernel/task_work.c:116
 [<ffffffff8113d02e>] exit_task_work include/linux/task_work.h:21 [inline]
 [<ffffffff8113d02e>] do_exit+0x82e/0x2a50 kernel/exit.c:833
 [<ffffffff81143718>] do_group_exit+0x108/0x320 kernel/exit.c:937
 [<ffffffff811663bc>] get_signal+0x55c/0x1600 kernel/signal.c:2315
 [<ffffffff81052c87>] do_signal+0x87/0x1960 arch/x86/kernel/signal.c:807
 [<ffffffff81003a35>] exit_to_usermode_loop+0xe5/0x130 arch/x86/entry/common.c:156
 [<ffffffff81006350>] prepare_exit_to_usermode arch/x86/entry/common.c:190 [inline]
 [<ffffffff81006350>] syscall_return_slowpath+0x1a0/0x1e0 arch/x86/entry/common.c:259
 [<ffffffff838ac666>] entry_SYSCALL_64_fastpath+0xc4/0xc6
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..