Re: [PATCH] certs: Reference revocation list for all keyrings

[Jarkko Sakkinen]

On Sat, Jan 21, 2023 at 03:20:46AM +0000, Jarkko Sakkinen wrote:
> On Tue, Jan 17, 2023 at 12:15:06PM -0500, Eric Snowberg wrote:
> > Systems booted with shim have a Forbidden Signature Database called mokx.
> > During boot, hashes and certs contained within the mokx are loaded into the
> > blacklist keyring.  When calling verify_pkcs7_message_sig the contents of
> > the blacklist keyring (or revocation list) are referenced when validating
> > keys on the platform keyring. Currently, when validating against the
> > secondary or builtin keyrings, the revocation list is not referenced.  Move
> > up the check to allow the revocation list to be used with all keyrings,
> > including the secondary and builtin, allowing the system owner to take
> > corrective action should a vulnerability be found within keys contained
> > within either keyring.
> > 
> > Signed-off-by: Eric Snowberg <eric.snowberg@xxxxxxxxxx>
> > ---
> >  certs/system_keyring.c | 12 ++++++------
> >  1 file changed, 6 insertions(+), 6 deletions(-)
> > 
> > diff --git a/certs/system_keyring.c b/certs/system_keyring.c
> > index 5042cc54fa5e..865a0510fdeb 100644
> > --- a/certs/system_keyring.c
> > +++ b/certs/system_keyring.c
> > @@ -243,6 +243,12 @@ int verify_pkcs7_message_sig(const void *data, size_t len,
> >  	if (ret < 0)
> >  		goto error;
> >  
> > +	ret = is_key_on_revocation_list(pkcs7);
> > +	if (ret != -ENOKEY) {
> > +		pr_devel("PKCS#7 key is on revocation list\n");
> > +		goto error;
> > +	}
> > +
> >  	if (!trusted_keys) {
> >  		trusted_keys = builtin_trusted_keys;
> >  	} else if (trusted_keys == VERIFY_USE_SECONDARY_KEYRING) {
> > @@ -262,12 +268,6 @@ int verify_pkcs7_message_sig(const void *data, size_t len,
> >  			pr_devel("PKCS#7 platform keyring is not available\n");
> >  			goto error;
> >  		}
> > -
> > -		ret = is_key_on_revocation_list(pkcs7);
> > -		if (ret != -ENOKEY) {
> > -			pr_devel("PKCS#7 platform key is on revocation list\n");
> > -			goto error;
> > -		}
> >  	}
> >  	ret = pkcs7_validate_trust(pkcs7, trusted_keys);
> >  	if (ret < 0) {
> > -- 
> > 2.27.0
> > 
> 
> Reviewed-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>

Should I pick this?

BR, Jarkko