syzbot

device syz0 entered promiscuous mode
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BUG: KASAN: slab-out-of-bounds in __tcp_hdrlen include/linux/tcp.h:35 [inline]
BUG: KASAN: slab-out-of-bounds in tcp_hdrlen include/linux/tcp.h:40 [inline]
BUG: KASAN: slab-out-of-bounds in qdisc_pkt_len_init net/core/dev.c:3087 [inline]
BUG: KASAN: slab-out-of-bounds in __dev_queue_xmit+0x1db6/0x1e60 net/core/dev.c:3369
Read of size 2 at addr ffff8801ca233a60 by task syzkaller440157/3345

CPU: 0 PID: 3345 Comm: syzkaller440157 Not tainted 4.9.76-g8e170a5 #21
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801c8397688 ffffffff81d93149 ffffea0007288c00 ffff8801ca233a60
 0000000000000000 ffff8801ca233a60 0000000000000005 ffff8801c83976c0
 ffffffff8153cb43 ffff8801ca233a60 0000000000000002 0000000000000000
Call Trace:
 [<ffffffff81d93149>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d93149>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff8153cb43>] print_address_description+0x73/0x280 mm/kasan/report.c:252
 [<ffffffff8153d065>] kasan_report_error mm/kasan/report.c:351 [inline]
 [<ffffffff8153d065>] kasan_report+0x275/0x360 mm/kasan/report.c:408
 [<ffffffff8153d184>] __asan_report_load2_noabort+0x14/0x20 mm/kasan/report.c:427
 [<ffffffff82f4ad06>] __tcp_hdrlen include/linux/tcp.h:35 [inline]
 [<ffffffff82f4ad06>] tcp_hdrlen include/linux/tcp.h:40 [inline]
 [<ffffffff82f4ad06>] qdisc_pkt_len_init net/core/dev.c:3087 [inline]
 [<ffffffff82f4ad06>] __dev_queue_xmit+0x1db6/0x1e60 net/core/dev.c:3369
 [<ffffffff810002b8>] ? 0xffffffff810002b8
 [<ffffffff82f4adc7>] dev_queue_xmit+0x17/0x20 net/core/dev.c:3458
 [<ffffffff835571dc>] packet_snd net/packet/af_packet.c:2953 [inline]
 [<ffffffff835571dc>] packet_sendmsg+0x2ccc/0x4760 net/packet/af_packet.c:2978
 [<ffffffff82ed5baa>] sock_sendmsg_nosec net/socket.c:635 [inline]
 [<ffffffff82ed5baa>] sock_sendmsg+0xca/0x110 net/socket.c:645
 [<ffffffff82ed5e16>] sock_write_iter+0x226/0x3b0 net/socket.c:843
 [<ffffffff8156d1ef>] new_sync_write fs/read_write.c:499 [inline]
 [<ffffffff8156d1ef>] __vfs_write+0x4bf/0x680 fs/read_write.c:512
 [<ffffffff8156eb19>] vfs_write+0x189/0x530 fs/read_write.c:560
 [<ffffffff81572609>] SYSC_write fs/read_write.c:607 [inline]
 [<ffffffff81572609>] SyS_write+0xd9/0x1b0 fs/read_write.c:599
 [<ffffffff81006fc7>] do_syscall_32_irqs_on arch/x86/entry/common.c:322 [inline]
 [<ffffffff81006fc7>] do_fast_syscall_32+0x2f7/0x890 arch/x86/entry/common.c:384
 [<ffffffff838b2334>] entry_SYSENTER_compat+0x74/0x83 arch/x86/entry/entry_64_compat.S:127

Allocated by task 3345:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
 save_stack+0x43/0xd0 mm/kasan/kasan.c:505
 set_track mm/kasan/kasan.c:517 [inline]
 kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:609
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:547
 slab_post_alloc_hook mm/slab.h:417 [inline]
 slab_alloc_node mm/slub.c:2715 [inline]
 slab_alloc mm/slub.c:2723 [inline]
 __kmalloc_track_caller+0xda/0x2b0 mm/slub.c:4232
 __kmalloc_reserve.isra.37+0x33/0xc0 net/core/skbuff.c:138
 __alloc_skb+0x119/0x600 net/core/skbuff.c:231
 alloc_skb include/linux/skbuff.h:919 [inline]
 alloc_skb_with_frags+0xac/0x4f0 net/core/skbuff.c:4657
 sock_alloc_send_pskb+0x5ad/0x740 net/core/sock.c:1893
 packet_alloc_skb net/packet/af_packet.c:2810 [inline]
 packet_snd net/packet/af_packet.c:2901 [inline]
 packet_sendmsg+0x18a1/0x4760 net/packet/af_packet.c:2978
 sock_sendmsg_nosec net/socket.c:635 [inline]
 sock_sendmsg+0xca/0x110 net/socket.c:645
 sock_write_iter+0x226/0x3b0 net/socket.c:843
 new_sync_write fs/read_write.c:499 [inline]
 __vfs_write+0x4bf/0x680 fs/read_write.c:512
 vfs_write+0x189/0x530 fs/read_write.c:560
 SYSC_write fs/read_write.c:607 [inline]
 SyS_write+0xd9/0x1b0 fs/read_write.c:599
 do_syscall_32_irqs_on arch/x86/entry/common.c:322 [inline]
 do_fast_syscall_32+0x2f7/0x890 arch/x86/entry/common.c:384
 entry_SYSENTER_compat+0x74/0x83 arch/x86/entry/entry_64_compat.S:127

Freed by task 0:
(stack is not available)

The buggy address belongs to the object at ffff8801ca233600
 which belongs to the cache kmalloc-1024 of size 1024
The buggy address is located 96 bytes to the right of
 1024-byte region [ffff8801ca233600, ffff8801ca233a00)
The buggy address belongs to the page:
page:ffffea0007288c00 count:1 mapcount:0 mapping:          (null) index:0x0 compound_mapcount: 0
flags: 0x8000000000004080(slab|head)
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801ca233900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801ca233980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8801ca233a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                                       ^
 ffff8801ca233a80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8801ca233b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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