Re: [RFC PATCH v2] x86/boot: add .sbat section to the bzImage

From: Luca Boccassi
Date: Wed Jul 12 2023 - 15:56:54 EST


On Wed, 12 Jul 2023 at 20:42, Borislav Petkov <bp@xxxxxxxxx> wrote:
>
> On Wed, Jul 12, 2023 at 08:35:14PM +0100, Luca Boccassi wrote:
> > No, all will not be fine, because stable branches exist, so it would
> > not be _one_ kernel version but N, with monotonically increasing
> > values of N. That doesn't work, and the reason for that are explained
> > in the protocol documentation that was linked in the initial mail.
>
> Lemme give Peter's example from earlier today:
>
> Bugfix A -> number 2
> Bugfix B -> number 3
>
> Tree backports only Bugfix B. Which number do you use?
>
> And so on and so on.

Everything < 3 is revoked _and_ the generation id in the stable branch
is _not_ bumped, because it's still vulnerable and so that branch is
effectively dead and unbootable on any system with secure boot
enabled. This is a revocation mechanism, not a bug tracking mechanism.
There's no mix-and-matching.

> Patch your own trees - this doesn't belong upstream.

Nah, it belongs in both places. Please read the documentation and
spend at least some time trying to understand the actual problem being
solved before commenting - or don't comment at all, that's fine too.