linux-ext4 - Re: [Bug 216283] New: FUZZ: BUG() triggered in fs/ext4/extent.c:ext4_ext_insert_extent() when mount and operate on crafted image

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Message-ID: <20220802092837.wqgut2i6kkbehcof@fedora>
Date:   Tue, 2 Aug 2022 11:28:37 +0200
From:   Lukas Czerner <lczerner@...hat.com>
To:     Dave Chinner <david@...morbit.com>
Cc:     "Darrick J. Wong" <djwong@...nel.org>, bugzilla-daemon@...nel.org,
        linux-ext4@...r.kernel.org
Subject: Re: [Bug 216283] New: FUZZ: BUG() triggered in
 fs/ext4/extent.c:ext4_ext_insert_extent() when mount and operate on crafted
 image

On Tue, Aug 02, 2022 at 08:45:51AM +1000, Dave Chinner wrote:

--- snip ---

> > 
> > Look, your entire argument hinges on the assumption that this is a
> > security vulnerability that could be exploited and the report makes the
> > situation worse. And that's very much debatable. I don't think it is and
> > Ted described it very well in his comment.
> 
> On systems that automount filesytsems when you plug in a USB drive
> (which most distros do out of the box) then a crash bug during mount
> is, at minimum, an annoying DOS vector. And if it can result in a
> buffer overflow, then....
> 
> > Asking for more information, or even asking reported to try to narrow
> > down the problem is of course fine.
> 
> Sure, nobody is questioning how we triage these issues - the
> question is over how they are reported and the forum under which the
> initial triage takes place
> 
> > But making sweeping claims about
> > moral and ethical responsibilities is always a little suspicious and
> > completely bogus in this case IMO.
> 
> Hand waving away the fact that fuzzer crash bugs won't be a security
> issue without having done any investigation is pretty much the whole
> problem here. This is not responsible behaviour.

Since it's obvious that the security status of this is disputed, then
please feel free to create guidelines stating that fuzzer bugs for xfs
are considered a security issues and reporters should follow guidelines
of responsible disclosure and bugs are not to be reported publicly.

Problem solved and no moralizing needed.

-Lukas

> 
> Cheers,
> 
> Dave.
> -- 
> Dave Chinner
> david@...morbit.com
>