[PATCH] audit: support for object context filters

This patch introduces object audit filters based on the elements
of the SELinux context.
Signed-off-by: NDarrel Goeddel <dgoeddel@trustedcs.com>
Acked-by: NStephen Smalley <sds@tycho.nsa.gov>

 kernel/auditfilter.c           |   25 +++++++++++++++++++++++++
 kernel/auditsc.c               |   40 ++++++++++++++++++++++++++++++++++++++++
 security/selinux/ss/services.c |   18 +++++++++++++++++-
 3 files changed, 82 insertions(+), 1 deletion(-)
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

kernel/auditfilter.c

@@ -475,6 +475,11 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
 		case AUDIT_SUBJ_TYPE:
 		case AUDIT_SUBJ_SEN:
 		case AUDIT_SUBJ_CLR:
+		case AUDIT_OBJ_USER:
+		case AUDIT_OBJ_ROLE:
+		case AUDIT_OBJ_TYPE:
+		case AUDIT_OBJ_LEV_LOW:
+		case AUDIT_OBJ_LEV_HIGH:
 			str = audit_unpack_string(&bufp, &remain, f->val);
 			if (IS_ERR(str))
 				goto exit_free;
@@ -616,6 +621,11 @@ static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
 		case AUDIT_SUBJ_TYPE:
 		case AUDIT_SUBJ_SEN:
 		case AUDIT_SUBJ_CLR:
+		case AUDIT_OBJ_USER:
+		case AUDIT_OBJ_ROLE:
+		case AUDIT_OBJ_TYPE:
+		case AUDIT_OBJ_LEV_LOW:
+		case AUDIT_OBJ_LEV_HIGH:
 			data->buflen += data->values[i] =
 				audit_pack_string(&bufp, f->se_str);
 			break;
@@ -659,6 +669,11 @@ static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
 		case AUDIT_SUBJ_TYPE:
 		case AUDIT_SUBJ_SEN:
 		case AUDIT_SUBJ_CLR:
+		case AUDIT_OBJ_USER:
+		case AUDIT_OBJ_ROLE:
+		case AUDIT_OBJ_TYPE:
+		case AUDIT_OBJ_LEV_LOW:
+		case AUDIT_OBJ_LEV_HIGH:
 			if (strcmp(a->fields[i].se_str, b->fields[i].se_str))
 				return 1;
 			break;
@@ -779,6 +794,11 @@ static struct audit_entry *audit_dupe_rule(struct audit_krule *old,
 		case AUDIT_SUBJ_TYPE:
 		case AUDIT_SUBJ_SEN:
 		case AUDIT_SUBJ_CLR:
+		case AUDIT_OBJ_USER:
+		case AUDIT_OBJ_ROLE:
+		case AUDIT_OBJ_TYPE:
+		case AUDIT_OBJ_LEV_LOW:
+		case AUDIT_OBJ_LEV_HIGH:
 			err = audit_dupe_selinux_field(&new->fields[i],
 						       &old->fields[i]);
 			break;
@@ -1542,6 +1562,11 @@ static inline int audit_rule_has_selinux(struct audit_krule *rule)
 		case AUDIT_SUBJ_TYPE:
 		case AUDIT_SUBJ_SEN:
 		case AUDIT_SUBJ_CLR:
+		case AUDIT_OBJ_USER:
+		case AUDIT_OBJ_ROLE:
+		case AUDIT_OBJ_TYPE:
+		case AUDIT_OBJ_LEV_LOW:
+		case AUDIT_OBJ_LEV_HIGH:
 			return 1;
 		}
 	}

kernel/auditsc.c

@@ -342,6 +342,46 @@ static int audit_filter_rules(struct task_struct *tsk,
 				                                  ctx);
 			}
 			break;
+		case AUDIT_OBJ_USER:
+		case AUDIT_OBJ_ROLE:
+		case AUDIT_OBJ_TYPE:
+		case AUDIT_OBJ_LEV_LOW:
+		case AUDIT_OBJ_LEV_HIGH:
+			/* The above note for AUDIT_SUBJ_USER...AUDIT_SUBJ_CLR
+			   also applies here */
+			if (f->se_rule) {
+				/* Find files that match */
+				if (name) {
+					result = selinux_audit_rule_match(
+					           name->osid, f->type, f->op,
+					           f->se_rule, ctx);
+				} else if (ctx) {
+					for (j = 0; j < ctx->name_count; j++) {
+						if (selinux_audit_rule_match(
+						      ctx->names[j].osid,
+						      f->type, f->op,
+						      f->se_rule, ctx)) {
+							++result;
+							break;
+						}
+					}
+				}
+				/* Find ipc objects that match */
+				if (ctx) {
+					struct audit_aux_data *aux;
+					for (aux = ctx->aux; aux;
+					     aux = aux->next) {
+						if (aux->type == AUDIT_IPC) {
+							struct audit_aux_data_ipcctl *axi = (void *)aux;
+							if (selinux_audit_rule_match(axi->osid, f->type, f->op, f->se_rule, ctx)) {
+								++result;
+								break;
+							}
+						}
+					}
+				}
+			}
+			break;
 		case AUDIT_ARG0:
 		case AUDIT_ARG1:
 		case AUDIT_ARG2:

security/selinux/ss/services.c

@@ -1848,12 +1848,17 @@ int selinux_audit_rule_init(u32 field, u32 op, char *rulestr,
 	case AUDIT_SUBJ_USER:
 	case AUDIT_SUBJ_ROLE:
 	case AUDIT_SUBJ_TYPE:
+	case AUDIT_OBJ_USER:
+	case AUDIT_OBJ_ROLE:
+	case AUDIT_OBJ_TYPE:
 		/* only 'equals' and 'not equals' fit user, role, and type */
 		if (op != AUDIT_EQUAL && op != AUDIT_NOT_EQUAL)
 			return -EINVAL;
 		break;
 	case AUDIT_SUBJ_SEN:
 	case AUDIT_SUBJ_CLR:
+	case AUDIT_OBJ_LEV_LOW:
+	case AUDIT_OBJ_LEV_HIGH:
 		/* we do not allow a range, indicated by the presense of '-' */
 		if (strchr(rulestr, '-'))
 			return -EINVAL;
@@ -1875,6 +1880,7 @@ int selinux_audit_rule_init(u32 field, u32 op, char *rulestr,
 
 	switch (field) {
 	case AUDIT_SUBJ_USER:
+	case AUDIT_OBJ_USER:
 		userdatum = hashtab_search(policydb.p_users.table, rulestr);
 		if (!userdatum)
 			rc = -EINVAL;
@@ -1882,6 +1888,7 @@ int selinux_audit_rule_init(u32 field, u32 op, char *rulestr,
 			tmprule->au_ctxt.user = userdatum->value;
 		break;
 	case AUDIT_SUBJ_ROLE:
+	case AUDIT_OBJ_ROLE:
 		roledatum = hashtab_search(policydb.p_roles.table, rulestr);
 		if (!roledatum)
 			rc = -EINVAL;
@@ -1889,6 +1896,7 @@ int selinux_audit_rule_init(u32 field, u32 op, char *rulestr,
 			tmprule->au_ctxt.role = roledatum->value;
 		break;
 	case AUDIT_SUBJ_TYPE:
+	case AUDIT_OBJ_TYPE:
 		typedatum = hashtab_search(policydb.p_types.table, rulestr);
 		if (!typedatum)
 			rc = -EINVAL;
@@ -1897,6 +1905,8 @@ int selinux_audit_rule_init(u32 field, u32 op, char *rulestr,
 		break;
 	case AUDIT_SUBJ_SEN:
 	case AUDIT_SUBJ_CLR:
+	case AUDIT_OBJ_LEV_LOW:
+	case AUDIT_OBJ_LEV_HIGH:
 		rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
 		break;
 	}
@@ -1949,6 +1959,7 @@ int selinux_audit_rule_match(u32 ctxid, u32 field, u32 op,
 	   without a match */
 	switch (field) {
 	case AUDIT_SUBJ_USER:
+	case AUDIT_OBJ_USER:
 		switch (op) {
 		case AUDIT_EQUAL:
 			match = (ctxt->user == rule->au_ctxt.user);
@@ -1959,6 +1970,7 @@ int selinux_audit_rule_match(u32 ctxid, u32 field, u32 op,
 		}
 		break;
 	case AUDIT_SUBJ_ROLE:
+	case AUDIT_OBJ_ROLE:
 		switch (op) {
 		case AUDIT_EQUAL:
 			match = (ctxt->role == rule->au_ctxt.role);
@@ -1969,6 +1981,7 @@ int selinux_audit_rule_match(u32 ctxid, u32 field, u32 op,
 		}
 		break;
 	case AUDIT_SUBJ_TYPE:
+	case AUDIT_OBJ_TYPE:
 		switch (op) {
 		case AUDIT_EQUAL:
 			match = (ctxt->type == rule->au_ctxt.type);
@@ -1980,7 +1993,10 @@ int selinux_audit_rule_match(u32 ctxid, u32 field, u32 op,
 		break;
 	case AUDIT_SUBJ_SEN:
 	case AUDIT_SUBJ_CLR:
-		level = (field == AUDIT_SUBJ_SEN ?
+	case AUDIT_OBJ_LEV_LOW:
+	case AUDIT_OBJ_LEV_HIGH:
+		level = ((field == AUDIT_SUBJ_SEN ||
+		          field == AUDIT_OBJ_LEV_LOW) ?
 		         &ctxt->range.level[0] : &ctxt->range.level[1]);
 		switch (op) {
 		case AUDIT_EQUAL: