Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Fri, 30 Aug 2019 17:31:54 +1000
From:   Dave Chinner <david@fromorbit.com>
To:     Austin Kim <austindh.kim@gmail.com>
Cc:     darrick.wong@oracle.com, linux-xfs@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] xfs: Initialize label array properly
Message-ID: <20190830073154.GO1119@dread.disaster.area>
References: <20190830053707.GA69101@LGEARND20B15>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20190830053707.GA69101@LGEARND20B15>
User-Agent: Mutt/1.10.1 (2018-07-13)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Fri, Aug 30, 2019 at 02:37:07PM +0900, Austin Kim wrote:
> In case kernel stack variable is not initialized properly,
> there is a risk of kernel information disclosure.
> 
> So, initialize 'char label[]' array with null characters.

Can you describe the information disclosure vector here? I can't see
any, mostly because this is the "set label" function and that
doesn't return anything to userspace.

We also zero the on-disk label before we copy the user label into
it, so I don't see that anything can leak onto disk, either...

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com