Re: [syzbot] WARNING in get_vaddr_frames

[syzbot]

syzbot has bisected this issue to:

commit 6647e76ab623b2b3fb2efe03a86e9c9046c52c33
Author: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Date:   Thu Dec 1 00:10:52 2022 +0000

    v4l2: don't fall back to follow_pfn() if pin_user_pages_fast() fails

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=115987c5480000
start commit:   e4cf7c25bae5 Merge tag 'kbuild-fixes-v6.2' of git://git.ke..
git tree:       upstream
final oops:     https://syzkaller.appspot.com/x/report.txt?x=135987c5480000
console output: https://syzkaller.appspot.com/x/log.txt?x=155987c5480000
kernel config:  https://syzkaller.appspot.com/x/.config?x=2651619a26b4d687
dashboard link: https://syzkaller.appspot.com/bug?extid=59a71007ccac79e8bb69
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=16ee1934480000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=101b997c480000

Reported-by: syzbot+59a71007ccac79e8bb69@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 6647e76ab623 ("v4l2: don't fall back to follow_pfn() if pin_user_pages_fast() fails")

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