==================================================================
BUG: KASAN: use-after-free in fanout_demux_rollover+0x49b/0x4d0 net/packet/af_packet.c:1392
Read of size 8 at addr ffff8801d8206cb0 by task syzkaller003430/8367

CPU: 0 PID: 8367 Comm: syzkaller003430 Not tainted 4.13.0-next-20170911+ #19
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
 print_address_description+0x73/0x250 mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report+0x24e/0x340 mm/kasan/report.c:409
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430
 fanout_demux_rollover+0x49b/0x4d0 net/packet/af_packet.c:1392
 packet_rcv_fanout+0x52e/0x7d0 net/packet/af_packet.c:1478
 deliver_skb net/core/dev.c:1859 [inline]
 deliver_ptype_list_skb net/core/dev.c:1874 [inline]
 __netif_receive_skb_core+0xc12/0x33d0 net/core/dev.c:4406
 __netif_receive_skb+0x2c/0x1b0 net/core/dev.c:4461
 netif_receive_skb_internal+0x10b/0x670 net/core/dev.c:4534
 napi_skb_finish net/core/dev.c:4895 [inline]
 napi_gro_receive+0x3d0/0x500 net/core/dev.c:4926
 receive_buf+0xcc5/0x51f0 drivers/net/virtio_net.c:841
 virtnet_receive drivers/net/virtio_net.c:1087 [inline]
 virtnet_poll+0x304/0xad0 drivers/net/virtio_net.c:1168
 napi_poll net/core/dev.c:5537 [inline]
 net_rx_action+0x792/0x1910 net/core/dev.c:5603
 __do_softirq+0x2bb/0xbd0 kernel/softirq.c:284
 invoke_softirq kernel/softirq.c:364 [inline]
 irq_exit+0x1d3/0x210 kernel/softirq.c:405
 exiting_irq arch/x86/include/asm/apic.h:638 [inline]
 do_IRQ+0xf6/0x190 arch/x86/kernel/irq.c:253
 common_interrupt+0x9d/0x9d arch/x86/entry/entry_64.S:598
 </IRQ>
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:814 [inline]
RIP: 0010:lock_release+0x69b/0xd70 kernel/locking/lockdep.c:4024
RSP: 0000:ffff8801bac2f3f0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff6e
RAX: dffffc0000000000 RBX: 1ffff10037585e83 RCX: 0000000000000000
RDX: 1ffffffff0b59305 RSI: ffffffff8130379e RDI: 0000000000000282
RBP: ffff8801bac2f5a0 R08: ffff8801bac2edf0 R09: 1ffff10037585e8f
R10: ffff8801d8d060c0 R11: 0000000000000002 R12: ffff8801bac2f478
R13: ffff8801d8d060c0 R14: 06cdf9ec61b0fb41 R15: 0000000000000003
 rcu_lock_release include/linux/rcupdate.h:249 [inline]
 rcu_read_unlock include/linux/rcupdate.h:686 [inline]
 filemap_map_pages+0x942/0x15d0 mm/filemap.c:2554
 do_fault_around mm/memory.c:3541 [inline]
 do_read_fault mm/memory.c:3575 [inline]
 do_fault mm/memory.c:3680 [inline]
 handle_pte_fault mm/memory.c:3910 [inline]
 __handle_mm_fault+0x1f57/0x39c0 mm/memory.c:4034
 handle_mm_fault+0x334/0x8d0 mm/memory.c:4071
 __do_page_fault+0x4f6/0xb60 arch/x86/mm/fault.c:1445
 do_page_fault+0xee/0x720 arch/x86/mm/fault.c:1520
 page_fault+0x22/0x30 arch/x86/entry/entry_64.S:1066
RIP: 0033:0x476af0
RSP: 002b:00007ffceb43e0f8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000000000044d19a
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 000000000000c17b R08: 0000000000000000 R09: 0000000000896940
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000407990 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 8328:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551
 __do_kmalloc mm/slab.c:3725 [inline]
 __kmalloc+0x162/0x760 mm/slab.c:3734
 kmalloc include/linux/slab.h:498 [inline]
 sk_prot_alloc+0x101/0x2a0 net/core/sock.c:1469
 sk_alloc+0x89/0x700 net/core/sock.c:1525
 packet_create+0x169/0xb00 net/packet/af_packet.c:3211
 __sock_create+0x4d4/0x850 net/socket.c:1262