Re: [PATCH 00/12] One more attempt at useful kernel lockdown

Mimi Zohar
2013-09-10T23:43:30Z

On Tue, 2013-09-10 at 12:44 -0700, H. Peter Anvin wrote:
> On 09/10/2013 12:17 PM, David Lang wrote:
> >>
> >> In theory these blobs are traceable to a manufacturer. It's not really
> >> an indication that it's "safe" more than it's an indication that it
> >> hasn't been changed. But I haven't chased this very hard yet because
> >> of below...
> >
> > well, not if you are trying to defend against root breaking in to the
> > machine.
> >
>
> And we have at least some drivers where we even have the firmware in the
> Linux kernel tree, and thus aren't opaque blobs at all.
>
> I suspect we'll need, at some point, a way for vendors that aren't
> already doing signatures on their firmware in a device-specific way to
> do so in a kernel-supported way. The easiest (in terms of getting
> vendors to play along, not necessarily technically) might be a PGP
> signature (either inline or standalone) and have the public key as part
> of the driver?

Why invent yet another method of verifying the integrity of a file based
on a signature? Why not use the existing method for appraising files?
Just create a new integrity hook at the appropriate place.

Mimi