WARNING in vmacache_find

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: ab9dfda2 Linux 4.14.180
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=132a4d92100000
kernel config: https://syzkaller.appspot.com/x/.config?x=221566a7407ce2de
dashboard link: https://syzkaller.appspot.com/bug?extid=64e1d18ecbe06fe81cc3
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

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+64e1d1...@syzkaller.appspotmail.com

------------[ cut here ]------------
WARNING: CPU: 1 PID: 18195 at mm/vmacache.c:64 vmacache_find+0x1c8/0x260 mm/vmacache.c:64
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 18195 Comm: syz-executor.3 Not tainted 4.14.180-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x13e/0x194 lib/dump_stack.c:58
panic+0x1f9/0x42d kernel/panic.c:183
__warn.cold+0x2f/0x30 kernel/panic.c:547
report_bug+0x20a/0x248 lib/bug.c:186
fixup_bug arch/x86/kernel/traps.c:177 [inline]
fixup_bug arch/x86/kernel/traps.c:172 [inline]
do_error_trap+0x195/0x2d0 arch/x86/kernel/traps.c:295
input: syz1 as /devices/virtual/input/input149
invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:963
RIP: 0010:vmacache_find+0x1c8/0x260 mm/vmacache.c:64
RSP: 0018:ffff888211567e48 EFLAGS: 00010297
RAX: ffff88800013a200 RBX: 0000000000000001 RCX: 00000000ef8adde0
RDX: 0000000000000000 RSI: 0000000000da0914 RDI: ffff888000000040
RBP: dffffc0000000000 R08: 0000000000000c54 R09: ffffffff8a065ae0
R10: ffff88800013aa88 R11: ffff88800013a200 R12: ffff888000000000
R13: ffff8880a8d5a640 R14: 0000000000da0914 R15: ffff88800013a200
find_vma+0x1c/0x140 mm/mmap.c:2149
__do_page_fault+0x300/0xb40 arch/x86/mm/fault.c:1388
page_fault+0x45/0x50 arch/x86/entry/entry_64.S:1122
RIP: 10960d:0x1095e0
RSP: 002d:000000000078bfa0 EFLAGS: 000003e8
Kernel Offset: disabled
Rebooting in 86400 seconds..


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.