------------[ cut here ]------------
WARNING: CPU: 1 PID: 12030 at net/xfrm/xfrm_policy.c:787 xfrm_policy_insert+0x646/0xf20 net/xfrm/xfrm_policy.c:787
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 12030 Comm: syz-executor0 Not tainted 4.9.99-g74fa0af4 #24
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801beb1f3b8 ffffffff81eb0f09 ffffffff83c484a0 00000000ffffffff
 0000000000000000 0000000000000001 0000000000000313 ffff8801beb1f478
 ffffffff8141f855 0000000041b58ab3 ffffffff843b8768 ffffffff8141f696
Call Trace:
 [<ffffffff81eb0f09>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb0f09>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff8141f855>] panic+0x1bf/0x3bc kernel/panic.c:179
 [<ffffffff8141fb41>] __warn.cold.9+0xc1/0x17f kernel/panic.c:542
 [<ffffffff8113461c>] warn_slowpath_null+0x2c/0x40 kernel/panic.c:585
 [<ffffffff834f2066>] xfrm_policy_insert+0x646/0xf20 net/xfrm/xfrm_policy.c:787
 [<ffffffff83523578>] xfrm_add_policy+0x248/0x4f0 net/xfrm/xfrm_user.c:1565
 [<ffffffff8351fce7>] xfrm_user_rcv_msg+0x3c7/0x6b0 net/xfrm/xfrm_user.c:2544
 [<ffffffff831ce505>] netlink_rcv_skb+0x145/0x370 net/netlink/af_netlink.c:2356
 [<ffffffff8351c86f>] xfrm_netlink_rcv+0x6f/0x90 net/xfrm/xfrm_user.c:2552
 [<ffffffff831cd0d8>] netlink_unicast_kernel net/netlink/af_netlink.c:1278 [inline]
 [<ffffffff831cd0d8>] netlink_unicast+0x4d8/0x6f0 net/netlink/af_netlink.c:1304
 [<ffffffff831cda7b>] netlink_sendmsg+0x78b/0xc10 net/netlink/af_netlink.c:1850
 [<ffffffff83012fcc>] sock_sendmsg_nosec net/socket.c:635 [inline]
 [<ffffffff83012fcc>] sock_sendmsg+0xcc/0x110 net/socket.c:645
 [<ffffffff83014a6c>] ___sys_sendmsg+0x6fc/0x840 net/socket.c:1969
 [<ffffffff83016ad9>] __sys_sendmsg+0xd9/0x190 net/socket.c:2003
 [<ffffffff83016bbd>] SYSC_sendmsg net/socket.c:2014 [inline]
 [<ffffffff83016bbd>] SyS_sendmsg+0x2d/0x50 net/socket.c:2010
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839f4653>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..