Comment 10 for bug 1736390

[ 118.059308] BUG: unable to handle kernel NULL pointer dereference at (null)
[ 118.065034] IP: rtmsg_ifa+0x2d/0xe0
[ 118.065744] *pdpt = 000000003434e001 *pde = 0000000000000000

[ 118.067166] Oops: 0000 [#1] SMP
[ 118.067863] Modules linked in: veth openvswitch nf_conntrack_ipv6 nf_nat_ipv6 nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_defrag_ipv6 nf_nat nf_conntrack ppdev kvm_intel kvm irqbypass parport_pc input_leds parport joydev serio_raw ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi autofs4 btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear crc32_pclmul pcbc hid_generic usbhid aesni_intel hid aes_i586 psmouse crypto_simd virtio_net cryptd virtio_blk floppy
[ 118.081568] CPU: 0 PID: 29 Comm: kworker/u2:1 Tainted: G W 4.13.0-19-generic #22~16.04.1-Ubuntu
[ 118.088041] Hardware name: OpenStack Foundation OpenStack Nova, BIOS 1.10.1-1ubuntu1~cloud0 04/01/2014
[ 118.090334] Workqueue: netns cleanup_net
[ 118.091146] task: f537e300 task.stack: f485a000
[ 118.092077] EIP: rtmsg_ifa+0x2d/0xe0
[ 118.092778] EFLAGS: 00010246 CPU: 0
[ 118.093654] EAX: 00000000 EBX: f3674e00 ECX: 00000000 EDX: 014000c0
[ 118.095002] ESI: 00000000 EDI: f34dad80 EBP: f485bd94 ESP: f485bd7c
[ 118.101126] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
[ 118.102531] CR0: 80050033 CR2: 00000000 CR3: 33df3860 CR4: 000406f0
[ 118.104276] Call Trace:
[ 118.105159] __inet_del_ifa+0x129/0x270
[ 118.106192] ? igmpv3_clear_delrec+0x28/0xb0
[ 118.107392] inetdev_event+0x1ff/0x4e0
[ 118.113963] ? __schedule+0x41e/0x8d0
[ 118.115418] notifier_call_chain+0x4e/0x70
[ 118.117049] ? notifier_call_chain+0x4e/0x70
[ 118.118081] raw_notifier_call_chain+0x11/0x20
[ 118.119125] call_netdevice_notifiers_info+0x2a/0x60
[ 118.125600] rollback_registered_many+0x268/0x370
[ 118.127652] unregister_netdevice_many+0x16/0x80
[ 118.129980] ? unregister_netdevice_many+0x16/0x80
[ 118.136510] default_device_exit_batch+0x126/0x150
[ 118.138577] ? do_wait_intr_irq+0x80/0x80
[ 118.140326] ops_exit_list.isra.8+0x4d/0x60
[ 118.142126] cleanup_net+0x18e/0x270
[ 118.143731] process_one_work+0x118/0x390
[ 118.149200] worker_thread+0x37/0x410
[ 118.150881] kthread+0xdb/0x110
[ 118.152617] ? process_one_work+0x390/0x390
[ 118.154530] ? kthread_create_on_node+0x20/0x20
[ 118.161804] ret_from_fork+0x19/0x24
[ 118.163523] Code: 66 66 90 55 89 e5 57 56 53 89 d7 89 ce 83 ec 0c 85 c9 89 45 ec 0f 84 93 00 00 00 8b 41 08 89 45 f0 8b 47 0c 31 c9 ba c0 00 40 01 <8b> 00 8b 80 20 03 00 00 6a ff 89 45 e8 b8 60 00 00 00 e8 7c 3e
[ 118.175426] EIP: rtmsg_ifa+0x2d/0xe0 SS:ESP: 0068:f485bd7c
[ 118.177188] CR2: 0000000000000000
[ 118.178305] ---[ end trace d1d2a116a66e2f9d ]---