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From: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Date: Mon, 19 Feb 2024 21:13:09 +0900
Message-ID: <CAKFNMonaAqehuHVW1beMNfgYm1Y8_hcjAZGAC1F5zs-3zcPQjQ@mail.gmail.com>
Subject: Re: [syzbot] [nilfs?] KASAN: use-after-free Read in nilfs_set_link
To: Jan Kara <jack@suse.cz>
Cc: syzbot <syzbot+4936b06b07f365af31cc@syzkaller.appspotmail.com>, axboe@kernel.dk, 
	brauner@kernel.org, linux-fsdevel@vger.kernel.org, 
	linux-kernel@vger.kernel.org, linux-nilfs@vger.kernel.org, 
	syzkaller-bugs@googlegroups.com
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On Mon, Feb 19, 2024 at 8:47=E2=80=AFPM 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=3D10639b34=
180000
> > 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=3D655f8abe9fe=
69b3b
> > dashboard link: https://syzkaller.appspot.com/bug?extid=3D4936b06b07f36=
5af31cc
> > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=3D11d62025e=
80000
> > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=3D13c38055e80=
000
> >
> > 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 sur=
e
> 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 maintaine=
r
> 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