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BUG: KASAN: use-after-free in ifname_compare_aligned include/linux/netfilter/x_tables.h:369 [inline]
BUG: KASAN: use-after-free in ip6_packet_match net/ipv6/netfilter/ip6_tables.c:89 [inline]
BUG: KASAN: use-after-free in ip6t_do_table+0x14e2/0x17e0 net/ipv6/netfilter/ip6_tables.c:333
Read of size 8 at addr ffff8801ca01c000 by task syz-executor.2/9072

CPU: 0 PID: 9072 Comm: syz-executor.2 Not tainted 4.9.141+ #1
 ffff8801ca2f7020 ffffffff81b42e79 ffffea0007280700 ffff8801ca01c000
 0000000000000000 ffff8801ca01c000 dffffc0000000000 ffff8801ca2f7058
 ffffffff815009b8[  213.221299] netlink: 20 bytes leftover after parsing attributes in process `syz-executor.0'.
 ffff8801ca01c000 0000000000000008 0000000000000000
 [<ffffffff81b42e79>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81b42e79>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff815009b8>] print_address_description+0x6c/0x234 mm/kasan/report.c:256
 [<ffffffff81500dc2>] kasan_report_error mm/kasan/report.c:355 [inline]
 [<ffffffff81500dc2>] kasan_report.cold.6+0x242/0x2fe mm/kasan/report.c:412
 [<ffffffff814f3074>] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
 [<ffffffff8277f202>] ifname_compare_aligned include/linux/netfilter/x_tables.h:369 [inline]
 [<ffffffff8277f202>] ip6_packet_match net/ipv6/netfilter/ip6_tables.c:89 [inline]
 [<ffffffff8277f202>] ip6t_do_table+0x14e2/0x17e0 net/ipv6/netfilter/ip6_tables.c:333
 [<ffffffff82787bd7>] ip6t_mangle_out net/ipv6/netfilter/ip6table_mangle.c:63 [inline]
 [<ffffffff82787bd7>] ip6table_mangle_hook+0x2d7/0x660 net/ipv6/netfilter/ip6table_mangle.c:85
 [<ffffffff823ddae6>] nf_iterate+0x126/0x310 net/netfilter/core.c:324
 [<ffffffff823ddde4>] nf_hook_slow+0x114/0x1e0 net/netfilter/core.c:355
 [<ffffffff827bcbe4>] nf_hook_thresh include/linux/netfilter.h:191 [inline]
 [<ffffffff827bcbe4>] nf_hook include/linux/netfilter.h:203 [inline]
 [<ffffffff827bcbe4>] __ip6_local_out+0x484/0x620 net/ipv6/output_core.c:164
 [<ffffffff827bcda9>] ip6_local_out+0x29/0x180 net/ipv6/output_core.c:174
 [<ffffffff826a4891>] ip6_send_skb+0xa1/0x340 net/ipv6/ip6_output.c:1751
 [<ffffffff82706689>] udp_v6_send_skb+0x429/0xe70 net/ipv6/udp.c:974
 [<ffffffff827072fd>] udp_v6_push_pending_frames+0x22d/0x340 net/ipv6/udp.c:1007
 [<ffffffff827092b1>] udpv6_sendmsg+0x1dc1/0x2430 net/ipv6/udp.c:1273
netlink: 20 bytes leftover after parsing attributes in process `syz-executor.0'.
 [<ffffffff825952f3>] inet_sendmsg+0x203/0x4d0 net/ipv4/af_inet.c:770
 [<ffffffff822a063b>] sock_sendmsg_nosec net/socket.c:648 [inline]
 [<ffffffff822a063b>] sock_sendmsg+0xbb/0x110 net/socket.c:658
 [<ffffffff822a209a>] ___sys_sendmsg+0x47a/0x840 net/socket.c:1982
 [<ffffffff822a55a1>] __sys_sendmmsg+0x161/0x3d0 net/socket.c:2072
 [<ffffffff822a5845>] SYSC_sendmmsg net/socket.c:2103 [inline]
 [<ffffffff822a5845>] SyS_sendmmsg+0x35/0x60 net/socket.c:2098
 [<ffffffff810056ef>] do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285
 [<ffffffff82817893>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Allocated by task 9078:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
 save_stack mm/kasan/kasan.c:505 [inline]
 set_track mm/kasan/kasan.c:517 [inline]
 kasan_kmalloc.part.1+0x62/0xf0 mm/kasan/kasan.c:609
 kasan_kmalloc+0xaf/0xc0 mm/kasan/kasan.c:594
 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+0xf0/0x2d0 mm/slub.c:4232
 __kmalloc_reserve.isra.5+0x33/0xc0 net/core/skbuff.c:138
 __alloc_skb+0x11a/0x5b0 net/core/skbuff.c:231
 alloc_skb_fclone include/linux/skbuff.h:966 [inline]
 sk_stream_alloc_skb+0xa3/0x5d0 net/ipv4/tcp.c:828
 tcp_connect+0xe88/0x2fa0 net/ipv4/tcp_output.c:3391
 tcp_v4_connect+0x19ec/0x1c00 net/ipv4/tcp_ipv4.c:250
 __inet_stream_connect+0x6e0/0xbf0 net/ipv4/af_inet.c:627
 tcp_sendmsg_fastopen net/ipv4/tcp.c:1116 [inline]
 tcp_sendmsg+0x218a/0x2fd0 net/ipv4/tcp.c:1145
 inet_sendmsg+0x203/0x4d0 net/ipv4/af_inet.c:770
 sock_sendmsg_nosec net/socket.c:648 [inline]
 sock_sendmsg+0xbb/0x110 net/socket.c:658
 SYSC_sendto net/socket.c:1683 [inline]
 SyS_sendto+0x220/0x370 net/socket.c:1651
 do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285
 entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Freed by task 9078:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
 save_stack mm/kasan/kasan.c:505 [inline]
 set_track mm/kasan/kasan.c:517 [inline]
 kasan_slab_free+0xac/0x190 mm/kasan/kasan.c:582
 slab_free_hook mm/slub.c:1355 [inline]
 slab_free_freelist_hook mm/slub.c:1377 [inline]
 slab_free mm/slub.c:2958 [inline]
 kfree+0xfb/0x310 mm/slub.c:3878
 skb_free_head+0x8b/0xb0 net/core/skbuff.c:580
 skb_release_data+0x338/0x3d0 net/core/skbuff.c:611
 skb_release_all+0x4a/0x60 net/core/skbuff.c:670
 __kfree_skb+0x15/0x20 net/core/skbuff.c:684
 tcp_drop+0xc4/0xf0 net/ipv4/tcp_input.c:4394
 tcp_rcv_state_process+0x284/0x4330 net/ipv4/tcp_input.c:6200
 tcp_v4_do_rcv+0x1a5/0x750 net/ipv4/tcp_ipv4.c:1440
 sk_backlog_rcv include/net/sock.h:871 [inline]
 __release_sock+0x13a/0x390 net/core/sock.c:2059
 release_sock+0x59/0x1c0 net/core/sock.c:2520
 tcp_sendmsg+0x178e/0x2fd0 net/ipv4/tcp.c:1372
 inet_sendmsg+0x203/0x4d0 net/ipv4/af_inet.c:770
 sock_sendmsg_nosec net/socket.c:648 [inline]
 sock_sendmsg+0xbb/0x110 net/socket.c:658
 SYSC_sendto net/socket.c:1683 [inline]
 SyS_sendto+0x220/0x370 net/socket.c:1651
 do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285
 entry_SYSCALL_64_after_swapgs+0x5d/0xdb

The buggy address belongs to the object at ffff8801ca01c000
 which belongs to the cache kmalloc-1024 of size 1024
The buggy address is located 0 bytes inside of
 1024-byte region [ffff8801ca01c000, ffff8801ca01c400)
The buggy address belongs to the page:
page:ffffea0007280700 count:1 mapcount:0 mapping:          (null) index:0x0 compound_mapcount: 0
flags: 0x4000000000004080(slab|head)
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801ca01bf00: fb fb fb fb fb fb fb fb fc fc fc fc fb fb fb fb
 ffff8801ca01bf80: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8801ca01c000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff8801ca01c080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801ca01c100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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