syzbot has bisected this issue to:
commit 6a66a7ded12baa6ebbb2e3e82f8cb91382814839
Author: zhangyi (F) <yi.zhang@xxxxxxxxxx>
Date: Thu Feb 13 06:38:20 2020 +0000
jbd2: move the clearing of b_modified flag to the journal_unmap_buffer()
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=14bd498ed00000
start commit: f69d02e3 Merge tag 'misc-5.12-2021-03-02' of git://git.ker..
git tree: upstream
final oops: https://syzkaller.appspot.com/x/report.txt?x=16bd498ed00000
console output: https://syzkaller.appspot.com/x/log.txt?x=12bd498ed00000
kernel config: https://syzkaller.appspot.com/x/.config?x=e0da2d01cc636e2c
dashboard link: https://syzkaller.appspot.com/bug?extid=9468df99cb63a4a4c4e1
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11770346d00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17be69ccd00000
Reported-by: syzbot+9468df99cb63a4a4c4e1@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 6a66a7ded12b ("jbd2: move the clearing of b_modified flag to the journal_unmap_buffer()")
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
