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BUG: KASAN: use-after-free in nla_strlcpy+0x13d/0x150 lib/nlattr.c:314
Read of size 1 at addr ffff8801d43a2ded by task syz-executor7/24908

CPU: 0 PID: 24908 Comm: syz-executor7 Not tainted 4.17.0-rc7+ #79
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:00007f7cad2ebc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f7cad2ec6d4 RCX: 0000000000455a09
RDX: 000000000000001f RSI: 0000000020000080 RDI: 0000000000000013
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000007a8 R14: 0000000000700860 R15: 0000000000000000

Allocated by task 9078:
 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
 unix_dgram_sendmsg+0x4f9/0x1730 net/unix/af_unix.c:1672
 sock_sendmsg_nosec net/socket.c:629 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:639
 __sys_sendto+0x3d7/0x670 net/socket.c:1789
 __do_sys_sendto net/socket.c:1801 [inline]
 __se_sys_sendto net/socket.c:1797 [inline]
 __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1797
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 2387:
 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]
 consume_skb+0x18b/0x550 net/core/skbuff.c:701
 skb_free_datagram+0x1a/0xf0 net/core/datagram.c:329
 unix_dgram_recvmsg+0xd83/0x1b30 net/unix/af_unix.c:2174
 sock_recvmsg_nosec net/socket.c:802 [inline]
 sock_recvmsg+0xd0/0x110 net/socket.c:809
 __sys_recvfrom+0x311/0x5d0 net/socket.c:1846
 __do_sys_recvfrom net/socket.c:1864 [inline]
 __se_sys_recvfrom net/socket.c:1860 [inline]
 __x64_sys_recvfrom+0xe1/0x1a0 net/socket.c:1860
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8801d43a2d40
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 173 bytes inside of
 512-byte region [ffff8801d43a2d40, ffff8801d43a2f40)
The buggy address belongs to the page:
page:ffffea000750e880 count:1 mapcount:0 mapping:ffff8801d43a20c0 index:0xffff8801d43a2ac0
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801d43a20c0 ffff8801d43a2ac0 0000000100000002
raw: ffffea0006229720 ffffea0006ddd2e0 ffff8801da800940 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d43a2c80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff8801d43a2d00: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
>ffff8801d43a2d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                          ^
 ffff8801d43a2e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801d43a2e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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