Re: [PATCH v3] KEYS: trusted: Fix trusted key backends when building as module

From: Andreas Rammhold
Date: Mon Sep 27 2021 - 16:08:44 EST


On 07:27 27.09.21, Mimi Zohar wrote:
> On Mon, 2021-09-27 at 10:51 +0200, Andreas Rammhold wrote:
> > On 09:47 13.09.21, Ahmad Fatoum wrote:
> > > Dear trusted key maintainers,
> > >
> > > On 30.07.21 03:28, Andreas Rammhold wrote:
> > > > Before this commit the kernel could end up with no trusted key sources
> > > > even though both of the currently supported backends (TPM and TEE) were
> > > > compiled as modules. This manifested in the trusted key type not being
> > > > registered at all.
> > > >
> > > > When checking if a CONFIG_… preprocessor variable is defined we only
> > > > test for the builtin (=y) case and not the module (=m) case. By using
> > > > the IS_REACHABLE() macro we do test for both cases.
> > > >
> > > > Fixes: 5d0682be3189 ("KEYS: trusted: Add generic trusted keys framework")
> > > > Signed-off-by: Andreas Rammhold <andreas@xxxxxxxxxxx>
> > > > Reviewed-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
> > > Does anyone intend to pick this up?
> >
> > Did this end up in any tree by now? I am wondering if I should resend
> > the patch instead. Perhaps it was just overlooked?
>
> For EVM environments only using trusted and encrypted keys, not file
> signatures, the trusted key is needed to decrypt the "master" key in
> order to verify kernel modules.

So what you are saying is that right now (before this patch & after this
patch) you could compile a kernel that wouldn't be able to load any
modules when the trusted keychain part is built as module?


Andi