Re: [PATCH] cert: Add kconfig dependency for validate_trust

From: David Howells
Date: Thu Feb 25 2021 - 09:45:32 EST


Eric Snowberg <eric.snowberg@xxxxxxxxxx> wrote:

> > I've added an extra config option to turn on SYSTEM_REVOCATION_LIST support.
>
> I believe this is ok. However currently, whenever the kernel finds either a
> EFI_CERT_SHA256_GUID or EFI_CERT_X509_SHA256_GUID entry in the dbx, it loads
> it into the blacklist keyring. Then anytime signature validation takes
> place, these entries are referenced. If there is a match, the signature
> check fails. Now with the inclusion of EFI_CERT_X509_GUID, I question why
> we want to enable it thru a Kconfig option, when we don’t for the other two
> types.

But we do.

mark_hash_blacklisted(), is_hash_blacklisted() and is_binary_blacklisted() do
nothing if CONFIG_SYSTEM_BLACKLIST_KEYRING=n.

David