==================================================================
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 3793 at addr ffff8880270a1811 by task syz-executor.0/16841

CPU: 1 PID: 16841 Comm: syz-executor.0 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
 tcp4_gso_segment net/ipv4/tcp_offload.c:51 [inline]
 tcp4_gso_segment+0x194/0x3a0 net/ipv4/tcp_offload.c:29
 inet_gso_segment+0x502/0x1110 net/ipv4/af_inet.c:1378
 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]
 ip_finish_output_gso net/ipv4/ip_output.c:269 [inline]
 __ip_finish_output net/ipv4/ip_output.c:303 [inline]
 __ip_finish_output+0x40d/0x640 net/ipv4/ip_output.c:290
 ip_finish_output+0x35/0x200 net/ipv4/ip_output.c:318
 NF_HOOK_COND include/linux/netfilter.h:290 [inline]
 ip_output+0x196/0x310 net/ipv4/ip_output.c:432
 dst_output include/net/dst.h:441 [inline]
 ip_local_out net/ipv4/ip_output.c:126 [inline]
 __ip_queue_xmit+0x8e9/0x1a00 net/ipv4/ip_output.c:532
 __tcp_transmit_skb+0x188c/0x38f0 net/ipv4/tcp_output.c:1405
 tcp_transmit_skb net/ipv4/tcp_output.c:1423 [inline]
 tcp_write_xmit+0xde7/0x6140 net/ipv4/tcp_output.c:2689
 tcp_sendmsg_locked+0xa1c/0x2e40 net/ipv4/tcp.c:1410
 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1459
 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:817
 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:00007fd0d2105c68 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 000000000045e219
RDX: fffffffffffffccf RSI: 0000000020000000 RDI: 0000000000000003
RBP: 000000000119bfd8 R08: 0000000000000000 R09: ffffffffffffff37
R10: 0000000000000240 R11: 0000000000000246 R12: 000000000119bf8c
R13: 00007ffd0b150b3f R14: 00007fd0d21069c0 R15: 000000000119bf8c

Allocated by task 16841:
 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]
 __tcp_send_ack.part.0+0x67/0x7a0 net/ipv4/tcp_output.c:3948
 __tcp_send_ack net/ipv4/tcp_output.c:3980 [inline]
 tcp_send_ack+0x7d/0xa0 net/ipv4/tcp_output.c:3980
 tcp_send_challenge_ack.constprop.0+0x24f/0x300 net/ipv4/tcp_input.c:3584
 tcp_validate_incoming+0x624/0x1c40 net/ipv4/tcp_input.c:5685
 tcp_rcv_state_process+0xb56/0x4cb0 net/ipv4/tcp_input.c:6390
 tcp_v4_do_rcv+0x320/0x870 net/ipv4/tcp_ipv4.c:1698
 sk_backlog_rcv include/net/sock.h:1016 [inline]
 __release_sock+0x134/0x3a0 net/core/sock.c:2542
 release_sock+0x54/0x1b0 net/core/sock.c:3066
 inet_wait_for_connect net/ipv4/af_inet.c:594 [inline]
 __inet_stream_connect+0x5db/0xee0 net/ipv4/af_inet.c:686
 tcp_sendmsg_fastopen net/ipv4/tcp.c:1191 [inline]
 tcp_sendmsg_locked+0x208f/0x2e40 net/ipv4/tcp.c:1233
 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1459
 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:817
 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

Freed by task 16841:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:357
 ____kasan_slab_free.part.0+0xe1/0x110 mm/kasan/common.c:364
 kasan_slab_free include/linux/kasan.h:192 [inline]
 slab_free_hook mm/slub.c:1548 [inline]
 slab_free_freelist_hook+0x82/0x1d0 mm/slub.c:1586
 slab_free mm/slub.c:3157 [inline]
 kfree+0xe5/0x7b0 mm/slub.c:4198
 skb_free_head net/core/skbuff.c:604 [inline]
 skb_release_data+0x622/0x750 net/core/skbuff.c:625
 skb_release_all net/core/skbuff.c:679 [inline]
 __kfree_skb+0x46/0x60 net/core/skbuff.c:693
 tcp_data_queue+0x273c/0x4b10 net/ipv4/tcp_input.c:4946
 tcp_rcv_state_process+0xdbc/0x4cb0 net/ipv4/tcp_input.c:6546
 tcp_v4_do_rcv+0x320/0x870 net/ipv4/tcp_ipv4.c:1698
 sk_backlog_rcv include/net/sock.h:1016 [inline]
 __release_sock+0x134/0x3a0 net/core/sock.c:2542
 release_sock+0x54/0x1b0 net/core/sock.c:3066
 inet_wait_for_connect net/ipv4/af_inet.c:594 [inline]
 __inet_stream_connect+0x5db/0xee0 net/ipv4/af_inet.c:686
 tcp_sendmsg_fastopen net/ipv4/tcp.c:1191 [inline]
 tcp_sendmsg_locked+0x208f/0x2e40 net/ipv4/tcp.c:1233
 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1459
 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:817
 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

Last potentially related work creation:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_record_aux_stack+0xe5/0x110 mm/kasan/generic.c:345
 kvfree_call_rcu+0x104/0x7c0 kernel/rcu/tree.c:3549
 neigh_destroy+0x3ff/0x5f0 net/core/neighbour.c:858
 neigh_release include/net/neighbour.h:425 [inline]
 neigh_cleanup_and_release+0x1fd/0x340 net/core/neighbour.c:103
 neigh_periodic_work+0x637/0x9e0 net/core/neighbour.c:940
 process_one_work+0x98d/0x15f0 kernel/workqueue.c:2275
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Second to last potentially related work creation:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_record_aux_stack+0xe5/0x110 mm/kasan/generic.c:345
 kvfree_call_rcu+0x104/0x7c0 kernel/rcu/tree.c:3549
 neigh_destroy+0x3ff/0x5f0 net/core/neighbour.c:858
 neigh_release include/net/neighbour.h:425 [inline]
 neigh_cleanup_and_release+0x1fd/0x340 net/core/neighbour.c:103
 neigh_periodic_work+0x637/0x9e0 net/core/neighbour.c:940
 process_one_work+0x98d/0x15f0 kernel/workqueue.c:2275
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

The buggy address belongs to the object at ffff8880270a1800
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 17 bytes inside of
 1024-byte region [ffff8880270a1800, ffff8880270a1c00)
The buggy address belongs to the page:
page:000000001904ce5d refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x270a0
head:000000001904ce5d order:2 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head)
raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888010041140
raw: 0000000000000000 0000000080080008 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880270a1700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880270a1780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880270a1800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff8880270a1880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880270a1900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================