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BUG: KASAN: use-after-free in memcpy include/linux/fortify-string.h:191 [inline]
BUG: KASAN: use-after-free in skb_copy_from_linear_data_offset include/linux/skbuff.h:3676 [inline]
BUG: KASAN: use-after-free in skb_segment+0x14ba/0x37a0 net/core/skbuff.c:4000
Read of size 144 at addr ffff88801878fff0 by task syz-executor.3/10502

CPU: 1 PID: 10502 Comm: syz-executor.3 Not tainted 5.11.0-rc3-next-20210118-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x107/0x163 lib/dump_stack.c:120
 print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:230
 __kasan_report mm/kasan/report.c:397 [inline]
 kasan_report.cold+0x79/0xd5 mm/kasan/report.c:414
 check_region_inline mm/kasan/generic.c:180 [inline]
 kasan_check_range+0x13d/0x180 mm/kasan/generic.c:186
 memcpy+0x20/0x60 mm/kasan/shadow.c:65
 memcpy include/linux/fortify-string.h:191 [inline]
 skb_copy_from_linear_data_offset include/linux/skbuff.h:3676 [inline]
 skb_segment+0x14ba/0x37a0 net/core/skbuff.c:4000
 tcp_gso_segment+0x33d/0x17e0 net/ipv4/tcp_offload.c:98
 tcp6_gso_segment net/ipv6/tcpv6_offload.c:65 [inline]
 tcp6_gso_segment+0x1a0/0x460 net/ipv6/tcpv6_offload.c:41
 ipv6_gso_segment+0x48d/0xf50 net/ipv6/ip6_offload.c:115
 skb_mac_gso_segment+0x26e/0x530 net/core/dev.c:3326
 __skb_gso_segment+0x330/0x6e0 net/core/dev.c:3399
 skb_gso_segment include/linux/netdevice.h:4708 [inline]
 validate_xmit_skb+0x69e/0xee0 net/core/dev.c:3644
 __dev_queue_xmit+0x988/0x2dd0 net/core/dev.c:4142
 packet_snd net/packet/af_packet.c:3006 [inline]
 packet_sendmsg+0x2406/0x52a0 net/packet/af_packet.c:3031
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:672
 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2345
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2399
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2432
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45e219
Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f1f050f1c68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045e219
RDX: 000000000000e869 RSI: 0000000020000440 RDI: 0000000000000004
RBP: 000000000119c068 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119c034
R13: 00007ffda5a6067f R14: 00007f1f050f29c0 R15: 000000000119c034

The buggy address belongs to the page:
page:00000000a93f1082 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1878c
head:00000000a93f1082 order:2 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010000(head)
raw: 00fff00000010000 dead000000000100 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88801878ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88801878ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888018790000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff888018790080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888018790100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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