netlink: 20 bytes leftover after parsing attributes in process `syz-executor.4'.
SELinux: failed to load policy
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: 1 PID: 11874 Comm: syz-executor.4 Not tainted 4.14.172-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8880903f6240 task.stack: ffff8880a4848000
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:ffff8880a484f270 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff8880a484f2f0 RCX: ffffc9000c246000
RDX: 0000000020000007 RSI: ffffffff85268ef7 RDI: 000000010000003a
RBP: ffff8880916e5dc0 R08: 0000000000000050 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000001 R14: 0000000100000002 R15: ffff8880a484f2a0
FS:  00007fa1bcd32700(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4bd7e95000 CR3: 00000000a5086000 CR4: 00000000001406e0
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:2432
 nfnetlink_rcv+0x1ab/0x1650 net/netfilter/nfnetlink.c:515
 netlink_unicast_kernel net/netlink/af_netlink.c:1286 [inline]
 netlink_unicast+0x437/0x620 net/netlink/af_netlink.c:1312
 netlink_sendmsg+0x733/0xbe0 net/netlink/af_netlink.c:1877
 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: 0033:0x45c479
RSP: 002b:00007fa1bcd31c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fa1bcd326d4 RCX: 000000000045c479
RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000003
RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000959 R14: 00000000004cbcd9 R15: 000000000076bf2c
Code: df 83 e9 04 e8 a6 f4 e5 fd 85 c0 0f 88 35 01 00 00 e8 39 b6 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: ffff8880a484f270
RIP: nfnetlink_parse_nat_setup+0x1cc/0x370 net/netfilter/nf_nat_core.c:784 RSP: ffff8880a484f270
---[ end trace c96dae20cea2f950 ]---
x_tables: ip_tables: l2tp match: used from hooks POSTROUTING, but only valid from PREROUTING/INPUT/FORWARD/OUTPUT