Re: [PATCH] xfs: Initialize label array properly

From: Dave Chinner
Date: Fri Aug 30 2019 - 03:32:00 EST


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@xxxxxxxxxxxxx