Re: [syzbot] [mm?] kernel BUG in vma_replace_policy

[syzbot]

syzbot has bisected this issue to:

commit 49b0638502da097c15d46cd4e871dbaa022caf7c
Author: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Date:   Fri Aug 4 15:27:19 2023 +0000

    mm: enable page walking API to lock vmas during the walk

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=11fd2348680000
start commit:   7733171926cc Merge tag 'mailbox-v6.6' of git://git.linaro...
git tree:       upstream
final oops:     https://syzkaller.appspot.com/x/report.txt?x=13fd2348680000
console output: https://syzkaller.appspot.com/x/log.txt?x=15fd2348680000
kernel config:  https://syzkaller.appspot.com/x/.config?x=b273cdfbc13e9a4b
dashboard link: https://syzkaller.appspot.com/bug?extid=b591856e0f0139f83023
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=15d4ecd0680000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1055c284680000

Reported-by: syzbot+b591856e0f0139f83023@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 49b0638502da ("mm: enable page walking API to lock vmas during the walk")

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