Re: general protection fault in path_openat

[syzbot]

syzbot has bisected this bug to:

commit d0cb50185ae942b03c4327be322055d622dc79f6
Author: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Date:   Sun Jan 26 14:29:34 2020 +0000

    do_last(): fetch directory ->i_mode and ->i_uid before it's too late

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=16a8d8b5e00000
start commit:   ccaaaf6f Merge tag 'mpx-for-linus' of git://git.kernel.org..
git tree:       upstream
final crash:    https://syzkaller.appspot.com/x/report.txt?x=15a8d8b5e00000
console output: https://syzkaller.appspot.com/x/log.txt?x=11a8d8b5e00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=879390c6b09ccf66
dashboard link: https://syzkaller.appspot.com/bug?extid=190005201ced78a74ad6
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1674c776e00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1565e101e00000

Reported-by: syzbot+190005201ced78a74ad6@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: d0cb50185ae9 ("do_last(): fetch directory ->i_mode and ->i_uid before it's too late")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection