Re: [PATCH v2] integrity: Always reference the blacklist keyring with apprasial

[Mimi Zohar <zohar@linux.ibm.com>]

On Wed, 2023-07-12 at 21:12 +0000, Eric Snowberg wrote:
> 
> > On Jul 12, 2023, at 11:40 AM, Mimi Zohar <zohar@linux.ibm.com> wrote:
> > 
> > On Wed, 2023-07-05 at 18:52 -0400, Eric Snowberg wrote:
> >> Commit 273df864cf746 ("ima: Check against blacklisted hashes for files with
> >> modsig") introduced an appraise_flag option for referencing the blacklist
> >> keyring.  Any matching binary found on this keyring fails signature
> >> validation. This flag only works with module appended signatures.
> >> 
> >> An important part of a PKI infrastructure is to have the ability to do
> >> revocation at a later time should a vulnerability be found.  Expand the
> >> revocation flag usage to all appraisal functions. The flag is now
> >> enabled by default. Setting the flag with an IMA policy has been
> >> deprecated. Without a revocation capability like this in place, only
> >> authenticity can be maintained. With this change, integrity can now be
> >> achieved with digital signature based IMA appraisal.
> >> 
> >> Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
> > 
> > Thanks, Eric.  Other than including "appraise_flag=check_blacklist"
> > when displaying the measurement list, it looks good.
> 
> Thanks for your review.  
> 
> I want to make sure I understand the request here.  Do you mean you 
> don’t want to see  “appraise_flag=check_blacklist”  when you cat 
> /sys/kernel/security/ima/policy?  Or are you referencing a change in the 
> /sys/kernel/security/ima/ascii_runtime_measurements list? Thanks.

The IMA policy rules as displayed via <securityfs>/ima/policy should
not contain  “appraise_flag=check_blacklist".

-- 
thanks,

Mimi