Re: [syzbot] KASAN: null-ptr-deref Read in hugepage_vma_check

[syzbot]

syzbot has bisected this issue to:

commit 0a44ebaaa3f3ecfacd2744467957882eabd92cec
Author: Yang Shi <shy828301@xxxxxxxxx>
Date:   Thu Jun 16 17:48:37 2022 +0000

    mm: thp: kill transparent_hugepage_active()

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=166ba760080000
start commit:   34d1d36073ea Add linux-next specific files for 20220621
git tree:       linux-next
final oops:     https://syzkaller.appspot.com/x/report.txt?x=156ba760080000
console output: https://syzkaller.appspot.com/x/log.txt?x=116ba760080000
kernel config:  https://syzkaller.appspot.com/x/.config?x=b24b62d1c051cfc8
dashboard link: https://syzkaller.appspot.com/bug?extid=4d875b4d2e2b60bae9b4
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=14097a3ff00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1466c63ff00000

Reported-by: syzbot+4d875b4d2e2b60bae9b4@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 0a44ebaaa3f3 ("mm: thp: kill transparent_hugepage_active()")

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