Re: [syzbot] [nilfs?] KASAN: use-after-free Read in nilfs_set_link

Ryusuke Konishi
2024-02-19T12:13:27Z

On Mon, Feb 19, 2024 at 8:47 PM Jan Kara wrote:
>
> On Sat 17-02-24 20:42:02, syzbot wrote:
> > syzbot suspects this issue was fixed by commit:
> >
> > commit 6f861765464f43a71462d52026fbddfc858239a5
> > Author: Jan Kara <jack@suse.cz>
> > Date: Wed Nov 1 17:43:10 2023 +0000
> >
> > fs: Block writes to mounted block devices
> >
> > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=10639b34180000
> > start commit: 52b1853b080a Merge tag 'i2c-for-6.7-final' of git://git.ke..
> > git tree: upstream
> > kernel config: https://syzkaller.appspot.com/x/.config?x=655f8abe9fe69b3b
> > dashboard link: https://syzkaller.appspot.com/bug?extid=4936b06b07f365af31cc
> > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11d62025e80000
> > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13c38055e80000
> >
> > If the result looks correct, please mark the issue as fixed by replying with:
> >
> > #syz fix: fs: Block writes to mounted block devices
>
> The reproducers don't seem to be doing anything suspicious so I'm not sure
> why the commit makes them not work anymore. There are no working
> reproducers for this bug though so I'll leave it upto the nilfs maintainer
> to decide what to do.
>
> Honza
>
> --
> Jan Kara <jack@suse.com>
> SUSE Labs, CR

Thank you for your comment.

This is one of the issues that I could not reproduce and could not
proceed with the analysis, but since it may be caused by an abnormal
state of the directory file (even if it was overwritten), I would like
to leave it as a subject of investigation.

Thanks,
Ryusuke Konishi