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BUG: KASAN: use-after-free in nla_strlcpy+0x13d/0x150 lib/nlattr.c:314
Read of size 1 at addr ffff8801c65b105d by task syz-executor5/16291

CPU: 1 PID: 16291 Comm: syz-executor5 Not tainted 4.17.0-rc6+ #62
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 print_address_description+0x6c/0x20b mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:430
 nla_strlcpy+0x13d/0x150 lib/nlattr.c:314
 nfnl_acct_new+0x574/0xc50 net/netfilter/nfnetlink_acct.c:118
 nfnetlink_rcv_msg+0xdb5/0xff0 net/netfilter/nfnetlink.c:212
 netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2448
 nfnetlink_rcv+0x1fe/0x1ba0 net/netfilter/nfnetlink.c:513
 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline]
 netlink_unicast+0x58b/0x740 net/netlink/af_netlink.c:1336
 netlink_sendmsg+0x9f0/0xfa0 net/netlink/af_netlink.c:1901
 sock_sendmsg_nosec net/socket.c:629 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:639
 sock_write_iter+0x35a/0x5a0 net/socket.c:908
 call_write_iter include/linux/fs.h:1784 [inline]
 new_sync_write fs/read_write.c:474 [inline]
 __vfs_write+0x64d/0x960 fs/read_write.c:487
 vfs_write+0x1f8/0x560 fs/read_write.c:549
 ksys_write+0xf9/0x250 fs/read_write.c:598
 __do_sys_write fs/read_write.c:610 [inline]
 __se_sys_write fs/read_write.c:607 [inline]
 __x64_sys_write+0x73/0xb0 fs/read_write.c:607
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x455a09
RSP: 002b:00007f3a349aac68 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f3a349ab6d4 RCX: 0000000000455a09
RDX: 000000000000001f RSI: 0000000020000040 RDI: 0000000000000013
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000077b R14: 00000000006ff428 R15: 0000000000000000

Allocated by task 15988:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553
 __do_kmalloc_node mm/slab.c:3682 [inline]
 __kmalloc_node_track_caller+0x47/0x70 mm/slab.c:3696
 __kmalloc_reserve.isra.38+0x3a/0xe0 net/core/skbuff.c:137
 __alloc_skb+0x14d/0x780 net/core/skbuff.c:205
 alloc_skb include/linux/skbuff.h:987 [inline]
 alloc_skb_with_frags+0x137/0x760 net/core/skbuff.c:5249
 sock_alloc_send_pskb+0x87a/0xae0 net/core/sock.c:2088
 sock_alloc_send_skb+0x32/0x40 net/core/sock.c:2105
 __ip6_append_data.isra.46+0x2086/0x3830 net/ipv6/ip6_output.c:1427
 ip6_make_skb+0x3c1/0x620 net/ipv6/ip6_output.c:1783
 udpv6_sendmsg+0x28cb/0x30f0 net/ipv6/udp.c:1329
 inet_sendmsg+0x19f/0x690 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:629 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:639
 ___sys_sendmsg+0x805/0x940 net/socket.c:2117
 __sys_sendmsg+0x115/0x270 net/socket.c:2155
 __do_sys_sendmsg net/socket.c:2164 [inline]
 __se_sys_sendmsg net/socket.c:2162 [inline]
 __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2162
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 15988:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3498 [inline]
 kfree+0xd9/0x260 mm/slab.c:3813
 skb_free_head+0x99/0xc0 net/core/skbuff.c:550
 skb_release_data+0x690/0x860 net/core/skbuff.c:570
 skb_release_all+0x4a/0x60 net/core/skbuff.c:627
 __kfree_skb net/core/skbuff.c:641 [inline]
 kfree_skb+0x195/0x560 net/core/skbuff.c:659
 __udp6_lib_mcast_deliver net/ipv6/udp.c:737 [inline]
 __udp6_lib_rcv+0x241c/0x3240 net/ipv6/udp.c:817
 udpv6_rcv+0x21/0x30 net/ipv6/udp.c:941
 ip6_input_finish+0x3ff/0x1a30 net/ipv6/ip6_input.c:284
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip6_input+0xe1/0x5e0 net/ipv6/ip6_input.c:327
 ip6_mc_input+0x3f7/0xd20 net/ipv6/ip6_input.c:404
 dst_input include/net/dst.h:450 [inline]
 ip6_rcv_finish+0x29c/0xa10 net/ipv6/ip6_input.c:71
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ipv6_rcv+0xed6/0x22a0 net/ipv6/ip6_input.c:208
 __netif_receive_skb_core+0x26f5/0x3630 net/core/dev.c:4592
 __netif_receive_skb+0x2c/0x1e0 net/core/dev.c:4657
 process_backlog+0x219/0x760 net/core/dev.c:5337
 napi_poll net/core/dev.c:5735 [inline]
 net_rx_action+0x7b7/0x1930 net/core/dev.c:5801
 __do_softirq+0x2e0/0xaf5 kernel/softirq.c:285

The buggy address belongs to the object at ffff8801c65b1040
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 29 bytes inside of
 512-byte region [ffff8801c65b1040, ffff8801c65b1240)
The buggy address belongs to the page:
page:ffffea0007196c40 count:1 mapcount:0 mapping:ffff8801c65b1040 index:0x0
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801c65b1040 0000000000000000 0000000100000006
raw: ffffea0006cb0c20 ffffea0006f343a0 ffff8801da800940 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801c65b0f00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff8801c65b0f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8801c65b1000: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
                                                    ^
 ffff8801c65b1080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801c65b1100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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