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BUG: KASAN: stack-out-of-bounds in deref_stack_reg+0x1b8/0x1d0
Read of size 8 at addr ffff8801b7997400 by task syz-executor3/3211

CPU: 1 PID: 3211 Comm: syz-executor3 Not tainted 4.14.0-rc5-next-20171017+ #34
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 dump_stack+0x173/0x237
 print_address_description+0x6e/0x250
 kasan_report+0x251/0x340
 deref_stack_reg+0x1b8/0x1d0
 unwind_next_frame+0xebc/0x1df0
 __save_stack_trace+0x6e/0xd0
 save_stack+0x32/0xb0
 kasan_kmalloc+0xa0/0xd0
 kmem_cache_alloc+0x114/0x740
 __build_skb+0x89/0x3c0
 __napi_alloc_skb+0x16e/0x2c0
 page_to_skb.isra.40+0xc7/0x760
 receive_buf+0x2ede/0x4d90
 virtnet_poll+0x31c/0xa90
 net_rx_action+0x72e/0x1790
 __do_softirq+0x2ba/0xafb
 irq_exit+0x1c7/0x200
 do_IRQ+0xe4/0x180
 common_interrupt+0x96/0x96
 </IRQ>
RIP: 0010:lock_is_held_type+0x84/0x200
RSP: 0018:ffff8801b79972d0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffffd9
RAX: dffffc0000000000 RBX: ffff8801cbdfa3c0 RCX: 0000000000000000
RDX: 1ffffffff0ad8f50 RSI: 00000000ffffffff RDI: ffffffff856c7a80
RBP: 0000000000000050 R08: 0000000000000002 R09: 00000000ad33622e
R10: 00000000f2275ad5 R11: 0000000000000000 R12: ffffffff85737c60
R13: 0000000000000080 R14: 00000000014000c0 R15: ffff8801d4f98000
 alloc_pid+0xa7/0x890

The buggy address belongs to the page:
page:ffffea0006de65c0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x200000000000000()
raw: 0200000000000000 0000000000000000 0000000000000000 00000000ffffffff
raw: ffffea0006de65e0 ffffea0006de65e0 0000000000000000 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801b7997300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801b7997380: 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 04 f2 f2
>ffff8801b7997400: f2 f2 f2 f2 f2 04 f2 f2 f2 f3 f3 f3 f3 00 00 00
                   ^
 ffff8801b7997480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801b7997500: 00 00 00 00 00 f1 f1 f1 f1 f8 f2 f2 f2 f2 f2 f2
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