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BUG: KASAN: slab-out-of-bounds in memcpy include/linux/fortify-string.h:191 [inline]
BUG: KASAN: slab-out-of-bounds in skb_copy_from_linear_data_offset include/linux/skbuff.h:3676 [inline]
BUG: KASAN: slab-out-of-bounds in skb_segment+0x14ba/0x37a0 net/core/skbuff.c:4000
Read of size 20 at addr ffff888028c6c7fc by task syz-executor.5/10015

CPU: 0 PID: 10015 Comm: syz-executor.5 Not tainted 5.11.0-rc4-next-20210119-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
 validate_xmit_skb_list+0xbc/0x120 net/core/dev.c:3694
 sch_direct_xmit+0x3f8/0xbd0 net/sched/sch_generic.c:298
 qdisc_restart net/sched/sch_generic.c:376 [inline]
 __qdisc_run+0x4ba/0x15f0 net/sched/sch_generic.c:384
 qdisc_run include/net/pkt_sched.h:136 [inline]
 qdisc_run include/net/pkt_sched.h:128 [inline]
 __dev_xmit_skb net/core/dev.c:3765 [inline]
 __dev_queue_xmit+0x1489/0x2dd0 net/core/dev.c:4119
 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_sendto+0x21c/0x320 net/socket.c:1975
 __do_sys_sendto net/socket.c:1987 [inline]
 __se_sys_sendto net/socket.c:1983 [inline]
 __x64_sys_sendto+0xdd/0x1b0 net/socket.c:1983
 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:00007fea5df56c68 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 000000000045e219
RDX: 0000000000003287 RSI: 0000000020000080 RDI: 0000000000000006
RBP: 000000000119bfd8 R08: 0000000000000000 R09: 000000000000023f
R10: 0000000000004021 R11: 0000000000000246 R12: 000000000119bf8c
R13: 00007ffcc009beaf R14: 00007fea5df579c0 R15: 000000000119bf8c

Allocated by task 10015:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:403 [inline]
 ____kasan_kmalloc mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc.constprop.0+0xa0/0xd0 mm/kasan/common.c:406
 kasan_slab_alloc include/linux/kasan.h:209 [inline]
 slab_post_alloc_hook mm/slab.h:518 [inline]
 slab_alloc_node mm/slub.c:2903 [inline]
 __kmalloc_node_track_caller+0x191/0x320 mm/slub.c:4569
 __kmalloc_reserve net/core/skbuff.c:142 [inline]
 __alloc_skb+0xae/0x5a0 net/core/skbuff.c:210
 alloc_skb include/linux/skbuff.h:1100 [inline]
 alloc_skb_with_frags+0x93/0x5d0 net/core/skbuff.c:5892
 sock_alloc_send_pskb+0x793/0x920 net/core/sock.c:2348
 packet_alloc_skb net/packet/af_packet.c:2854 [inline]
 packet_snd net/packet/af_packet.c:2949 [inline]
 packet_sendmsg+0x19ee/0x52a0 net/packet/af_packet.c:3031
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:672
 __sys_sendto+0x21c/0x320 net/socket.c:1975
 __do_sys_sendto net/socket.c:1987 [inline]
 __se_sys_sendto net/socket.c:1983 [inline]
 __x64_sys_sendto+0xdd/0x1b0 net/socket.c:1983
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

The buggy address belongs to the object at ffff888028c6c000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 2044 bytes inside of
 2048-byte region [ffff888028c6c000, ffff888028c6c800)
The buggy address belongs to the page:
page:00000000953d09ad refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x28c68
head:00000000953d09ad order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head)
raw: 00fff00000010200 ffffea0001e39600 0000000200000002 ffff888010042000
raw: 0000000000000000 0000000080080008 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888028c6c700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888028c6c780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888028c6c800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                   ^
 ffff888028c6c880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888028c6c900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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