------------[ cut here ]------------
WARNING: CPU: 0 PID: 13670 at net/key/af_key.c:111 pfkey_sock_destruct+0x307/0x350 net/key/af_key.c:111
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 13670 Comm: syz-executor0 Not tainted 4.9.119-g9dc978d #23
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff88019d8bf910 ffffffff81eb4be9 ffffffff83c48980 00000000ffffffff
 0000000000000000 0000000000000001 000000000000006f ffff88019d8bf9d0
 ffffffff81421c95 0000000041b58ab3 ffffffff843bc020 ffffffff81421ad6
Call Trace:
 [<ffffffff81eb4be9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb4be9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81421c95>] panic+0x1bf/0x3bc kernel/panic.c:179
 [<ffffffff81421f81>] __warn.cold.9+0xc1/0x17f kernel/panic.c:542
 [<ffffffff8113683c>] warn_slowpath_null+0x2c/0x40 kernel/panic.c:585
 [<ffffffff836b6117>] pfkey_sock_destruct+0x307/0x350 net/key/af_key.c:111
 [<ffffffff830230f5>] __sk_destruct+0x55/0x590 net/core/sock.c:1428
 [<ffffffff8302ab83>] sk_destruct+0x63/0x80 net/core/sock.c:1463
 [<ffffffff8302abef>] __sk_free+0x4f/0x220 net/core/sock.c:1471
 [<ffffffff8302adeb>] sk_free+0x2b/0x40 net/core/sock.c:1482
 [<ffffffff836a145e>] sock_put include/net/sock.h:1588 [inline]
 [<ffffffff836a145e>] pfkey_release+0x25e/0x2f0 net/key/af_key.c:194
 [<ffffffff83015ab6>] sock_release+0x96/0x1c0 net/socket.c:600
 [<ffffffff83015bf6>] sock_close+0x16/0x20 net/socket.c:1047
 [<ffffffff81578693>] __fput+0x263/0x700 fs/file_table.c:208
 [<ffffffff81578bb5>] ____fput+0x15/0x20 fs/file_table.c:244
 [<ffffffff8119838c>] task_work_run+0x10c/0x180 kernel/task_work.c:116
 [<ffffffff8116aa53>] get_signal+0x1133/0x1450 kernel/signal.c:2151
 [<ffffffff81052637>] do_signal+0x87/0x19f0 arch/x86/kernel/signal.c:807
 [<ffffffff81005581>] exit_to_usermode_loop+0xe1/0x120 arch/x86/entry/common.c:157
 [<ffffffff810064d4>] prepare_exit_to_usermode arch/x86/entry/common.c:191 [inline]
 [<ffffffff810064d4>] syscall_return_slowpath arch/x86/entry/common.c:260 [inline]
 [<ffffffff810064d4>] do_syscall_64+0x364/0x490 arch/x86/entry/common.c:287
 [<ffffffff839fccd3>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..