Re: [PATCH 8/8] ima: Differentiate auditing policy rules from "audit" actions

[Steve Grubb]

On Wednesday, May 30, 2018 8:49:20 AM EDT Richard Guy Briggs wrote:
> On 2018-05-24 16:11, Stefan Berger wrote:
> > The AUDIT_INTEGRITY_RULE is used for auditing IMA policy rules and
> > the IMA "audit" policy action.  This patch defines
> > AUDIT_INTEGRITY_POLICY_RULE to reflect the IMA policy rules.
> > 
> > With this change we now call integrity_audit_msg_common() to get
> > common integrity auditing fields. This now produces the following
> > record when parsing an IMA policy rule:
> > 
> > type=UNKNOWN[1806] msg=audit(1527004216.690:311): action=dont_measure \
> > 
> >   fsmagic=0x9fa0 pid=1613 uid=0 auid=0 ses=2 \
> >   subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 \
> >   op=policy_update cause=parse_rule comm="echo" exe="/usr/bin/echo" \
> >   tty=tty2 res=1
> > 
> > Signed-off-by: Stefan Berger <stefanb@xxxxxxxxxxxxxxxxxx>
> > ---
> > 
> >  include/uapi/linux/audit.h          | 3 ++-
> >  security/integrity/ima/ima_policy.c | 5 +++--
> >  2 files changed, 5 insertions(+), 3 deletions(-)
> > 
> > diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
> > index 4e61a9e05132..776e0abd35cf 100644
> > --- a/include/uapi/linux/audit.h
> > +++ b/include/uapi/linux/audit.h
> > @@ -146,7 +146,8 @@
> > 
> >  #define AUDIT_INTEGRITY_STATUS	    1802 /* Integrity enable status */
> >  #define AUDIT_INTEGRITY_HASH	    1803 /* Integrity HASH type */
> >  #define AUDIT_INTEGRITY_PCR	    1804 /* PCR invalidation msgs */
> > 
> > -#define AUDIT_INTEGRITY_RULE	    1805 /* policy rule */
> > +#define AUDIT_INTEGRITY_RULE	    1805 /* IMA "audit" action policy msgs 
> > */ +#define AUDIT_INTEGRITY_POLICY_RULE 1806 /* IMA policy rules */
> > 
> >  #define AUDIT_KERNEL		2000	/* Asynchronous audit record. NOT A 
REQUEST.
> >  */
> > 
> > diff --git a/security/integrity/ima/ima_policy.c
> > b/security/integrity/ima/ima_policy.c index 3aed25a7178a..a8ae47a386b4
> > 100644
> > --- a/security/integrity/ima/ima_policy.c
> > +++ b/security/integrity/ima/ima_policy.c
> > @@ -634,7 +634,7 @@ static int ima_parse_rule(char *rule, struct
> > ima_rule_entry *entry)> 
> >  	int result = 0;
> >  	
> >  	ab = integrity_audit_log_start(NULL, GFP_KERNEL,
> > 
> > -				       AUDIT_INTEGRITY_RULE);
> > +				       AUDIT_INTEGRITY_POLICY_RULE);
> 
> Is it possible to connect this record to a syscall by replacing the
> first parameter (NULL) by current->context?

We don't want to add syscall records to everything. That messes up schemas 
and existing code. The integrity events are 1 record in size and should stay 
that way. This saves disk space and improves readability.

-Steve

> >  	entry->uid = INVALID_UID;
> >  	entry->fowner = INVALID_UID;
> > 
> > @@ -926,7 +926,8 @@ static int ima_parse_rule(char *rule, struct
> > ima_rule_entry *entry)> 
> >  		temp_ima_appraise |= IMA_APPRAISE_FIRMWARE;
> >  	
> >  	else if (entry->func == POLICY_CHECK)
> >  	
> >  		temp_ima_appraise |= IMA_APPRAISE_POLICY;
> > 
> > -	audit_log_format(ab, "res=%d", !result);
> > +	integrity_audit_msg_common(ab, NULL, NULL,
> > +				   "policy_update", "parse_rule", result);
> > 
> >  	audit_log_end(ab);
> >  	return result;
> >  
> >  }
> 
> - RGB
> 
> --
> Richard Guy Briggs <rgb@xxxxxxxxxx>
> Sr. S/W Engineer, Kernel Security, Base Operating Systems
> Remote, Ottawa, Red Hat Canada
> IRC: rgb, SunRaycer
> Voice: +1.647.777.2635, Internal: (81) 32635