Re: [PATCH v2] ima: instantiate the bprm_creds_for_exec() hook

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

On Thu, 2024-12-05 at 19:30 -0500, Paul Moore wrote:
> On Dec  4, 2024 Mimi Zohar <zohar@linux.ibm.com> wrote:
> > 
> > Like direct file execution (e.g. ./script.sh), indirect file execution
> > (e.g. sh script.sh) needs to be measured and appraised.  Instantiate
> > the new security_bprm_creds_for_exec() hook to measure and verify the
> > indirect file's integrity.  Unlike direct file execution, indirect file
> > execution is optionally enforced by the interpreter.
> > 
> > Differentiate kernel and userspace enforced integrity audit messages.
> > 
> > Co-developed-by: Roberto Sassu <roberto.sassu@huawei.com>
> > Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
> > Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
> > ---
> > Changelog v3:
> > - Mickael: add comment ima_bprm_creds_for_exec(), minor code cleanup,
> >   add Co-developed-by tag.
> > 
> > Changelog v2:
> > - Mickael: Use same audit messages with new audit message number
> > - Stefan Berger: Return boolean from is_bprm_creds_for_exec()
> > 
> >  include/uapi/linux/audit.h            |  1 +
> >  security/integrity/ima/ima_appraise.c | 27 +++++++++++++++++++++++--
> >  security/integrity/ima/ima_main.c     | 29 +++++++++++++++++++++++++++
> >  3 files changed, 55 insertions(+), 2 deletions(-)
> > 
> > diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
> > index 75e21a135483..826337905466 100644
> > --- a/include/uapi/linux/audit.h
> > +++ b/include/uapi/linux/audit.h
> > @@ -161,6 +161,7 @@
> >  #define AUDIT_INTEGRITY_RULE	    1805 /* policy rule */
> >  #define AUDIT_INTEGRITY_EVM_XATTR   1806 /* New EVM-covered xattr */
> >  #define AUDIT_INTEGRITY_POLICY_RULE 1807 /* IMA policy rules */
> > +#define AUDIT_INTEGRITY_DATA_CHECK  1808 /* Userspace enforced data integrity */
> 
> I worry that "DATA_CHECK" is a bit vague, should we change the name so
> that there is some hint of either userspace enforcement or
> AT_EXECVE_CHECK?
> 
> What about AUDIT_INTEGRITY_DATA_USER?

The emphasis should be on userspace - AUDIT_INTEGRITY_USERSPACE.

Mimi