------------[ cut here ]------------
WARNING: CPU: 1 PID: 5972 at net/xfrm/xfrm_policy.c:786 xfrm_policy_insert+0x6ff/0xda0 net/xfrm/xfrm_policy.c:786
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 5972 Comm: syz-executor0 Not tainted 4.9.83-gda9fb78 #40
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801b2f3f3a8 ffffffff81d95149 ffffffff83a480c0 ffff8801b2f3f480
 ffffffff83f42a00 ffffffff833c032f 0000000000000009 ffff8801b2f3f470
 ffffffff8142f6c1 0000000041b58ab3 ffffffff8418b1f0 ffffffff8142f505
Call Trace:
 [<ffffffff81d95149>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d95149>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff8142f6c1>] panic+0x1bc/0x3a8 kernel/panic.c:179
 [<ffffffff811311c4>] __warn+0x1c4/0x1e0 kernel/panic.c:542
 [<ffffffff8113142c>] warn_slowpath_null+0x2c/0x40 kernel/panic.c:585
 [<ffffffff833c032f>] xfrm_policy_insert+0x6ff/0xda0 net/xfrm/xfrm_policy.c:786
 [<ffffffff833ef97f>] xfrm_add_policy+0x38f/0x660 net/xfrm/xfrm_user.c:1546
 [<ffffffff833ec18d>] xfrm_user_rcv_msg+0x40d/0x6a0 net/xfrm/xfrm_user.c:2525
 [<ffffffff8309652e>] netlink_rcv_skb+0x13e/0x370 net/netlink/af_netlink.c:2351
 [<ffffffff833e868f>] xfrm_netlink_rcv+0x6f/0x90 net/xfrm/xfrm_user.c:2533
 [<ffffffff830950b1>] netlink_unicast_kernel net/netlink/af_netlink.c:1275 [inline]
 [<ffffffff830950b1>] netlink_unicast+0x511/0x750 net/netlink/af_netlink.c:1301
 [<ffffffff83095bd8>] netlink_sendmsg+0x8e8/0xc50 net/netlink/af_netlink.c:1847
 [<ffffffff82ed8baa>] sock_sendmsg_nosec net/socket.c:635 [inline]
 [<ffffffff82ed8baa>] sock_sendmsg+0xca/0x110 net/socket.c:645
 [<ffffffff82eda7c1>] ___sys_sendmsg+0x6d1/0x7e0 net/socket.c:1969
 [<ffffffff82edc7f6>] __sys_sendmsg+0xd6/0x190 net/socket.c:2003
 [<ffffffff82edc8dd>] SYSC_sendmsg net/socket.c:2014 [inline]
 [<ffffffff82edc8dd>] SyS_sendmsg+0x2d/0x50 net/socket.c:2010
 [<ffffffff81006504>] do_syscall_64+0x1a4/0x490 arch/x86/entry/common.c:282
 [<ffffffff838b4e7d>] entry_SYSCALL_64_after_swapgs+0x47/0xc5
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..