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BUG: KASAN: use-after-free in __list_del_entry_valid+0xf1/0x100 lib/list_debug.c:51
Read of size 8 at addr ffff8881bbf2f470 by task kworker/1:2/3434

CPU: 1 PID: 3434 Comm: kworker/1:2 Not tainted 4.20.0-rc6-next-20181210+ #164
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_power_efficient neigh_periodic_work
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x244/0x39d lib/dump_stack.c:113
 print_address_description.cold.4+0x9/0x1ff mm/kasan/report.c:187
 kasan_report.cold.5+0x1b/0x39 mm/kasan/report.c:317
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135
 __list_del_entry_valid+0xf1/0x100 lib/list_debug.c:51
 __list_del_entry include/linux/list.h:117 [inline]
 list_del_init include/linux/list.h:159 [inline]
 neigh_mark_dead+0x13b/0x410 net/core/neighbour.c:125
 neigh_periodic_work+0x89a/0xc30 net/core/neighbour.c:905
 process_one_work+0xc90/0x1c40 kernel/workqueue.c:2153
 worker_thread+0x17f/0x1390 kernel/workqueue.c:2296
 kthread+0x35a/0x440 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

Allocated by task 20774:
 save_stack+0x43/0xd0 mm/kasan/common.c:73
 set_track mm/kasan/common.c:85 [inline]
 kasan_kmalloc+0xcb/0xd0 mm/kasan/common.c:482
 __do_kmalloc_node mm/slab.c:3671 [inline]
 __kmalloc_node_track_caller+0x4d/0x70 mm/slab.c:3685
 __kmalloc_reserve.isra.38+0x41/0xe0 net/core/skbuff.c:137
 __alloc_skb+0x155/0x770 net/core/skbuff.c:205
 alloc_skb include/linux/skbuff.h:1008 [inline]
 alloc_uevent_skb+0x84/0x1da lib/kobject_uevent.c:289
 uevent_net_broadcast_untagged lib/kobject_uevent.c:325 [inline]
 kobject_uevent_net_broadcast lib/kobject_uevent.c:408 [inline]
 kobject_uevent_env+0xa52/0x101e lib/kobject_uevent.c:589
 kvm_uevent_notify_change.part.32+0x2f8/0x450 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3926
 kvm_uevent_notify_change arch/x86/kvm/../../../virt/kvm/kvm_main.c:3885 [inline]
 kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:3223 [inline]
 kvm_dev_ioctl+0xc81/0x1ae0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3245
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:509 [inline]
 do_vfs_ioctl+0x1de/0x1790 fs/ioctl.c:696
 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:713
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl fs/ioctl.c:718 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 3727:
 save_stack+0x43/0xd0 mm/kasan/common.c:73
 set_track mm/kasan/common.c:85 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/common.c:444
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:452
 __cache_free mm/slab.c:3485 [inline]
 kfree+0xcf/0x230 mm/slab.c:3804
 skb_free_head+0x99/0xc0 net/core/skbuff.c:550
 skb_release_data+0x70c/0x9a0 net/core/skbuff.c:570
 skb_release_all+0x4a/0x60 net/core/skbuff.c:627
 __kfree_skb net/core/skbuff.c:641 [inline]
 consume_skb+0x1ae/0x570 net/core/skbuff.c:701
 skb_free_datagram+0x1a/0xf0 net/core/datagram.c:329
 netlink_recvmsg+0x70f/0x1480 net/netlink/af_netlink.c:1996
 sock_recvmsg_nosec net/socket.c:795 [inline]
 sock_recvmsg+0xd0/0x110 net/socket.c:802
 ___sys_recvmsg+0x2b6/0x680 net/socket.c:2279
 __sys_recvmsg+0x11a/0x280 net/socket.c:2328
 __do_sys_recvmsg net/socket.c:2338 [inline]
 __se_sys_recvmsg net/socket.c:2335 [inline]
 __x64_sys_recvmsg+0x78/0xb0 net/socket.c:2335
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8881bbf2f200
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 624 bytes inside of
 1024-byte region [ffff8881bbf2f200, ffff8881bbf2f600)
The buggy address belongs to the page:
page:ffffea0006efcb80 count:1 mapcount:0 mapping:ffff8881da800ac0 index:0x0 compound_mapcount: 0
flags: 0x2fffc0000010200(slab|head)
raw: 02fffc0000010200 ffffea0007642b08 ffffea000707ca88 ffff8881da800ac0
raw: 0000000000000000 ffff8881bbf2e000 0000000100000007 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8881bbf2f300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881bbf2f380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881bbf2f400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                             ^
 ffff8881bbf2f480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881bbf2f500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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