WARNING in xfrm_policy_inexact_insert

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    296d05cb Merge tag 'riscv/for-v5.3-rc4' of git://git.kerne..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=163917c2600000
kernel config:  https://syzkaller.appspot.com/x/.config?x=2031e7d221391b8a
dashboard link: https://syzkaller.appspot.com/bug?extid=0ffe44015de138d98e79
compiler:       clang version 9.0.0 (/home/glider/llvm/clang  
80fee25776c2fb61e74c1ecb1a523375c2500b69)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+0ffe44015de138d98e79@xxxxxxxxxxxxxxxxxxxxxxxxx

------------[ cut here ]------------
WARNING: CPU: 1 PID: 907 at net/xfrm/xfrm_policy.c:1506  
xfrm_policy_insert_inexact_list net/xfrm/xfrm_policy.c:1506 [inline]
WARNING: CPU: 1 PID: 907 at net/xfrm/xfrm_policy.c:1506  
xfrm_policy_inexact_insert+0x102a/0x1540 net/xfrm/xfrm_policy.c:1195
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 907 Comm: syz-executor.2 Not tainted 5.3.0-rc3+ #72
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1d8/0x2f8 lib/dump_stack.c:113
 panic+0x25c/0x799 kernel/panic.c:219
 __warn+0x22f/0x230 kernel/panic.c:576
 report_bug+0x190/0x290 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:179 [inline]
 do_error_trap+0xd7/0x440 arch/x86/kernel/traps.c:272
 do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:291
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1028
RIP: 0010:xfrm_policy_insert_inexact_list net/xfrm/xfrm_policy.c:1506  
[inline]
RIP: 0010:xfrm_policy_inexact_insert+0x102a/0x1540  
net/xfrm/xfrm_policy.c:1195
Code: c1 03 38 c1 0f 8c 0a f7 ff ff 48 89 df e8 6e 3a 38 fb e9 fd f6 ff ff  
e8 44 41 ff fa 48 c7 c7 82 bf 3a 88 31 c0 e8 e9 8a e8 fa <0f> 0b e9 b4 fc  
ff ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c 04 f7 ff
RSP: 0018:ffff888088ca78b0 EFLAGS: 00010246
RAX: 0000000000000024 RBX: ffff8880a752d8a0 RCX: 2f5cd5be3d6cb100
RDX: ffffc9000a35f000 RSI: 0000000000005caf RDI: 0000000000005cb0
RBP: ffff888088ca79b8 R08: ffffffff815cf524 R09: ffffed1015d66088
R10: ffffed1015d66088 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000000
 xfrm_policy_insert+0xdf/0xce0 net/xfrm/xfrm_policy.c:1574
 pfkey_spdadd+0xe47/0x1980 net/key/af_key.c:2325
 pfkey_process net/key/af_key.c:2834 [inline]
 pfkey_sendmsg+0xacd/0xeb0 net/key/af_key.c:3673
 sock_sendmsg_nosec net/socket.c:637 [inline]
 sock_sendmsg net/socket.c:657 [inline]
 ___sys_sendmsg+0x60d/0x910 net/socket.c:2311
 __sys_sendmsg net/socket.c:2356 [inline]
 __do_sys_sendmsg net/socket.c:2365 [inline]
 __se_sys_sendmsg net/socket.c:2363 [inline]
 __x64_sys_sendmsg+0x17c/0x200 net/socket.c:2363
 do_syscall_64+0xfe/0x140 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459829
Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7  
48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff  
ff 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fa22f5f1c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459829
RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000000000003
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa22f5f26d4
R13: 00000000004c76ea R14: 00000000004dceb0 R15: 00000000ffffffff
Kernel Offset: disabled
Rebooting in 86400 seconds..


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