netlink: 8 bytes leftover after parsing attributes in process `syz-executor.4'.
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 0 PID: 12512 Comm: syz-executor.4 Not tainted 4.14.174-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff88808ddbe340 task.stack: ffff888053490000
RIP: 0010:nfnetlink_parse_nat net/netfilter/nf_nat_core.c:747 [inline]
RIP: 0010:nfnetlink_parse_nat_setup+0x1cc/0x370 net/netfilter/nf_nat_core.c:784
RSP: 0018:ffff888053497270 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff8880534972f0 RCX: ffffc9000c045000
RDX: 0000008180000008 RSI: ffffffff8526ccb7 RDI: 0000040c00000040
RBP: ffff8880a5a9edc0 R08: 000000000000004f R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000001 R14: 0000040c00000008 R15: ffff8880534972a0
FS:  00007f619c1b4700(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000b70004 CR3: 00000000a560d000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 ctnetlink_parse_nat_setup+0x70/0x490 net/netfilter/nf_conntrack_netlink.c:1421
 ctnetlink_setup_nat net/netfilter/nf_conntrack_netlink.c:1491 [inline]
 ctnetlink_create_conntrack+0x437/0x1040 net/netfilter/nf_conntrack_netlink.c:1840
 ctnetlink_new_conntrack+0x460/0xc30 net/netfilter/nf_conntrack_netlink.c:1964
 nfnetlink_rcv_msg+0xa08/0xc00 net/netfilter/nfnetlink.c:214
 netlink_rcv_skb+0x127/0x370 net/netlink/af_netlink.c:2433
 nfnetlink_rcv+0x1ab/0x1650 net/netfilter/nfnetlink.c:515
 netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline]
 netlink_unicast+0x437/0x620 net/netlink/af_netlink.c:1313
 netlink_sendmsg+0x733/0xbe0 net/netlink/af_netlink.c:1878
 sock_sendmsg_nosec net/socket.c:646 [inline]
 sock_sendmsg+0xc5/0x100 net/socket.c:656
 ___sys_sendmsg+0x70a/0x840 net/socket.c:2062
 __sys_sendmsg+0xa3/0x120 net/socket.c:2096
 SYSC_sendmsg net/socket.c:2107 [inline]
 SyS_sendmsg+0x27/0x40 net/socket.c:2103
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45c849
RSP: 002b:00007f619c1b3c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f619c1b46d4 RCX: 000000000045c849
RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000003
RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000095c R14: 00000000004cc0fb R15: 000000000076bf0c
Code: df 83 e9 04 e8 06 ea e5 fd 85 c0 0f 88 35 01 00 00 e8 c9 7a 33 fc 49 8d 7e 38 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 89 01 00 00 4c 89 fe 48 89 df 41 ff 56 38 85 
RIP: nfnetlink_parse_nat net/netfilter/nf_nat_core.c:747 [inline] RSP: ffff888053497270
RIP: nfnetlink_parse_nat_setup+0x1cc/0x370 net/netfilter/nf_nat_core.c:784 RSP: ffff888053497270
audit: type=1804 audit(1585406093.345:56): pid=12522 uid=0 auid=4294967295 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 op="invalid_pcr" cause="ToMToU" comm="syz-executor.3" name="/root/syzkaller-testdir585419828/syzkaller.OsYtsJ/210/file0/file0" dev="loop3" ino=16 res=1
 loop5: p2 p3 p4
---[ end trace d00ce615b396e496 ]---