==================================================================
BUG: KASAN: use-after-free in fanout_demux_rollover+0x49b/0x4d0 net/packet/af_packet.c:1392
Read of size 8 at addr ffff8801d4330a70 by task syzkaller943089/12351

CPU: 0 PID: 12351 Comm: syzkaller943089 Not tainted 4.14.0-rc1+ #48
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:kasan_poison_shadow mm/kasan/kasan.c:64 [inline]
RIP: 0010:kasan_unpoison_shadow+0x35/0x50 mm/kasan/kasan.c:69
RSP: 0000:ffff8801d3cb7138 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff6e
RAX: ffffed0037df4000 RBX: ffffed0037df4200 RCX: 0000000000000000
RDX: 0000000000000200 RSI: 0000000000000000 RDI: ffffed0037df4200
RBP: ffff8801d3cb7148 R08: 0000000000100000 R09: ffffed0037df4000
R10: 0000000000000000 R11: ffffea0006fbe800 R12: 0000000000001000
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8801d3cb7828
 kasan_alloc_pages+0x38/0x40 mm/kasan/kasan.c:311
 post_alloc_hook mm/page_alloc.c:1761 [inline]
 prep_new_page mm/page_alloc.c:1770 [inline]
 get_page_from_freelist+0x20a9/0x3430 mm/page_alloc.c:3175
 __alloc_pages_nodemask+0x588/0xd80 mm/page_alloc.c:4197
 alloc_pages_vma+0xc8/0x4b0 mm/mempolicy.c:1999
 alloc_zeroed_user_highpage_movable include/linux/highmem.h:183 [inline]
 do_anonymous_page mm/memory.c:3103 [inline]
 handle_pte_fault mm/memory.c:3908 [inline]
 __handle_mm_fault+0x24fd/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: 0033:0x4030ef
RSP: 002b:00007ffc704557a0 EFLAGS: 00010206
RAX: 00007f0d7a019000 RBX: 0000000000800000 RCX: 0000000000445c9a
RDX: 0000000000801000 RSI: 0000000000801000 RDI: 0000000000000000
RBP: 00007ffc70455880 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc70455810
R13: 00007f0d7a819700 R14: 0000000000000000 R15: 0000000000000000