BUG: unable to handle kernel NULL pointer dereference at           (null)
IP:           (null)
PGD 20b2cd067 P4D 20b2cd067 PUD 21079a067 PMD 0 
Oops: 0010 [#1] SMP
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 21238 Comm: syz-executor5 Not tainted 4.15.0-rc3-next-20171214+ #67
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:          (null)
RSP: 0018:ffffc90000eef950 EFLAGS: 00010212
RAX: 0000000000010000 RBX: ffff88020b6de000 RCX: ffffffff816783d1
RDX: 0000000000000008 RSI: ffff88020b1be700 RDI: ffff88020b6de000
RBP: ffffc90000eef988 R08: 000000000002c498 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88020b1be700
R13: 0000000000000008 R14: ffff88020d1e3c50 R15: 0000000000000000
FS:  00007faa5a22a700(0000) GS:ffff88021fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000020bbc6001 CR4: 00000000001606f0
DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 esp_init_authenc+0x258/0x400 net/ipv6/esp6.c:855
 esp6_init_state+0xeb/0x110 net/ipv6/esp6.c:878
 __xfrm_init_state+0x25d/0x660 net/xfrm/xfrm_state.c:2259
 xfrm_init_state+0x1c/0x20 net/xfrm/xfrm_state.c:2285
 pfkey_msg2xfrm_state net/key/af_key.c:1274 [inline]
 pfkey_add+0x6ed/0xbf0 net/key/af_key.c:1491
 pfkey_process+0x255/0x290 net/key/af_key.c:2809
 pfkey_sendmsg+0x193/0x310 net/key/af_key.c:3648
 sock_sendmsg_nosec net/socket.c:636 [inline]
 sock_sendmsg+0x51/0x70 net/socket.c:646
 ___sys_sendmsg+0x35e/0x3b0 net/socket.c:2026
 __sys_sendmsg+0x50/0x90 net/socket.c:2060
 SYSC_sendmsg net/socket.c:2071 [inline]
 SyS_sendmsg+0x2d/0x50 net/socket.c:2067
 entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x452a09
RSP: 002b:00007faa5a229c58 EFLAGS: 00000212 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000452a09
RDX: 0000000000000000 RSI: 00000000205f5000 RDI: 0000000000000013
RBP: 000000000000056d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f52d8
R13: 00000000ffffffff R14: 00007faa5a22a6d4 R15: 0000000000000000
Code:  Bad RIP value.
RIP:           (null) RSP: ffffc90000eef950
CR2: 0000000000000000
---[ end trace 826fdd463beacc87 ]---