lsm: use lsm_prop in security_audit_rule_match

Change the secid parameter of security_audit_rule_match
to a lsm_prop structure pointer. Pass the entry from the
lsm_prop structure for the approprite slot to the LSM hook.

Change the users of security_audit_rule_match to use the
lsm_prop instead of a u32. The scaffolding function lsmprop_init()
fills the structure with the value of the old secid, ensuring that
it is available to the appropriate module hook. The sources of
the secid, security_task_getsecid() and security_inode_getsecid(),
will be converted to use the lsm_prop structure later in the series.
At that point the use of lsmprop_init() is dropped.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: subject line tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>

Author: cschaufler

include/linux/lsm_hook_defs.h

@@ -416,7 +416,8 @@ LSM_HOOK(void, LSM_RET_VOID, key_post_create_or_update, struct key *keyring,
 LSM_HOOK(int, 0, audit_rule_init, u32 field, u32 op, char *rulestr,
 	 void **lsmrule, gfp_t gfp)
 LSM_HOOK(int, 0, audit_rule_known, struct audit_krule *krule)
-LSM_HOOK(int, 0, audit_rule_match, u32 secid, u32 field, u32 op, void *lsmrule)
+LSM_HOOK(int, 0, audit_rule_match, struct lsm_prop *prop, u32 field, u32 op,
+	 void *lsmrule)
 LSM_HOOK(void, LSM_RET_VOID, audit_rule_free, void *lsmrule)
 #endif /* CONFIG_AUDIT */
 

include/linux/security.h

@@ -2115,7 +2115,8 @@ static inline void security_key_post_create_or_update(struct key *keyring,
 int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule,
 			     gfp_t gfp);
 int security_audit_rule_known(struct audit_krule *krule);
-int security_audit_rule_match(u32 secid, u32 field, u32 op, void *lsmrule);
+int security_audit_rule_match(struct lsm_prop *prop, u32 field, u32 op,
+			      void *lsmrule);
 void security_audit_rule_free(void *lsmrule);
 
 #else
@@ -2131,8 +2132,8 @@ static inline int security_audit_rule_known(struct audit_krule *krule)
 	return 0;
 }
 
-static inline int security_audit_rule_match(u32 secid, u32 field, u32 op,
-					    void *lsmrule)
+static inline int security_audit_rule_match(struct lsm_prop *prop, u32 field,
+					    u32 op, void *lsmrule)
 {
 	return 0;
 }

kernel/auditfilter.c

@@ -1339,8 +1339,8 @@ int audit_filter(int msgtype, unsigned int listtype)
 
 		for (i = 0; i < e->rule.field_count; i++) {
 			struct audit_field *f = &e->rule.fields[i];
+			struct lsm_prop prop = { };
 			pid_t pid;
-			u32 sid;
 
 			switch (f->type) {
 			case AUDIT_PID:
@@ -1370,9 +1370,12 @@ int audit_filter(int msgtype, unsigned int listtype)
 			case AUDIT_SUBJ_SEN:
 			case AUDIT_SUBJ_CLR:
 				if (f->lsm_rule) {
-					security_current_getsecid_subj(&sid);
-					result = security_audit_rule_match(sid,
-						   f->type, f->op, f->lsm_rule);
+					/* scaffolding */
+					security_current_getsecid_subj(
+							&prop.scaffold.secid);
+					result = security_audit_rule_match(
+						   &prop, f->type, f->op,
+						   f->lsm_rule);
 				}
 				break;
 			case AUDIT_EXE:

kernel/auditsc.c

@@ -471,6 +471,7 @@ static int audit_filter_rules(struct task_struct *tsk,
 	const struct cred *cred;
 	int i, need_sid = 1;
 	u32 sid;
+	struct lsm_prop prop = { };
 	unsigned int sessionid;
 
 	if (ctx && rule->prio <= ctx->prio)
@@ -681,7 +682,10 @@ static int audit_filter_rules(struct task_struct *tsk,
 					security_current_getsecid_subj(&sid);
 					need_sid = 0;
 				}
-				result = security_audit_rule_match(sid, f->type,
+				/* scaffolding */
+				prop.scaffold.secid = sid;
+				result = security_audit_rule_match(&prop,
+								   f->type,
 								   f->op,
 								   f->lsm_rule);
 			}
@@ -696,15 +700,19 @@ static int audit_filter_rules(struct task_struct *tsk,
 			if (f->lsm_rule) {
 				/* Find files that match */
 				if (name) {
+					/* scaffolding */
+					prop.scaffold.secid = name->osid;
 					result = security_audit_rule_match(
-								name->osid,
+								&prop,
 								f->type,
 								f->op,
 								f->lsm_rule);
 				} else if (ctx) {
 					list_for_each_entry(n, &ctx->names_list, list) {
+						/* scaffolding */
+						prop.scaffold.secid = n->osid;
 						if (security_audit_rule_match(
-								n->osid,
+								&prop,
 								f->type,
 								f->op,
 								f->lsm_rule)) {
@@ -716,7 +724,9 @@ static int audit_filter_rules(struct task_struct *tsk,
 				/* Find ipc objects that match */
 				if (!ctx || ctx->type != AUDIT_IPC)
 					break;
-				if (security_audit_rule_match(ctx->ipc.osid,
+				/* scaffolding */
+				prop.scaffold.secid = ctx->ipc.osid;
+				if (security_audit_rule_match(&prop,
 							      f->type, f->op,
 							      f->lsm_rule))
 					++result;

security/apparmor/audit.c

@@ -264,13 +264,17 @@ int aa_audit_rule_known(struct audit_krule *rule)
 	return 0;
 }
 
-int aa_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule)
+int aa_audit_rule_match(struct lsm_prop *prop, u32 field, u32 op, void *vrule)
 {
 	struct aa_audit_rule *rule = vrule;
 	struct aa_label *label;
 	int found = 0;
 
-	label = aa_secid_to_label(sid);
+	/* scaffolding */
+	if (!prop->apparmor.label && prop->scaffold.secid)
+		label = aa_secid_to_label(prop->scaffold.secid);
+	else
+		label = prop->apparmor.label;
 
 	if (!label)
 		return -ENOENT;

security/apparmor/include/audit.h

@@ -202,6 +202,6 @@ static inline int complain_error(int error)
 void aa_audit_rule_free(void *vrule);
 int aa_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule, gfp_t gfp);
 int aa_audit_rule_known(struct audit_krule *rule);
-int aa_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule);
+int aa_audit_rule_match(struct lsm_prop *prop, u32 field, u32 op, void *vrule);
 
 #endif /* __AA_AUDIT_H */

security/integrity/ima/ima.h

@@ -555,7 +555,7 @@ static inline void ima_filter_rule_free(void *lsmrule)
 {
 }
 
-static inline int ima_filter_rule_match(u32 secid, u32 field, u32 op,
+static inline int ima_filter_rule_match(struct lsm_prop *prop, u32 field, u32 op,
 					void *lsmrule)
 {
 	return -EINVAL;

security/integrity/ima/ima_policy.c

@@ -635,7 +635,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule,
 		return false;
 	for (i = 0; i < MAX_LSM_RULES; i++) {
 		int rc = 0;
-		u32 osid;
+		struct lsm_prop prop = { };
 
 		if (!lsm_rule->lsm[i].rule) {
 			if (!lsm_rule->lsm[i].args_p)
@@ -649,15 +649,18 @@ static bool ima_match_rules(struct ima_rule_entry *rule,
 		case LSM_OBJ_USER:
 		case LSM_OBJ_ROLE:
 		case LSM_OBJ_TYPE:
-			security_inode_getsecid(inode, &osid);
-			rc = ima_filter_rule_match(osid, lsm_rule->lsm[i].type,
+			/* scaffolding */
+			security_inode_getsecid(inode, &prop.scaffold.secid);
+			rc = ima_filter_rule_match(&prop, lsm_rule->lsm[i].type,
 						   Audit_equal,
 						   lsm_rule->lsm[i].rule);
 			break;
 		case LSM_SUBJ_USER:
 		case LSM_SUBJ_ROLE:
 		case LSM_SUBJ_TYPE:
-			rc = ima_filter_rule_match(secid, lsm_rule->lsm[i].type,
+			/* scaffolding */
+			prop.scaffold.secid = secid;
+			rc = ima_filter_rule_match(&prop, lsm_rule->lsm[i].type,
 						   Audit_equal,
 						   lsm_rule->lsm[i].rule);
 			break;

security/security.c

@@ -5570,7 +5570,7 @@ void security_audit_rule_free(void *lsmrule)
 
 /**
  * security_audit_rule_match() - Check if a label matches an audit rule
- * @secid: security label
+ * @prop: security label
  * @field: LSM audit field
  * @op: matching operator
  * @lsmrule: audit rule
@@ -5581,9 +5581,10 @@ void security_audit_rule_free(void *lsmrule)
  * Return: Returns 1 if secid matches the rule, 0 if it does not, -ERRNO on
  *         failure.
  */
-int security_audit_rule_match(u32 secid, u32 field, u32 op, void *lsmrule)
+int security_audit_rule_match(struct lsm_prop *prop, u32 field, u32 op,
+			      void *lsmrule)
 {
-	return call_int_hook(audit_rule_match, secid, field, op, lsmrule);
+	return call_int_hook(audit_rule_match, prop, field, op, lsmrule);
 }
 #endif /* CONFIG_AUDIT */
 

security/selinux/include/audit.h

@@ -41,15 +41,15 @@ void selinux_audit_rule_free(void *rule);
 
 /**
  * selinux_audit_rule_match - determine if a context ID matches a rule.
- * @sid: the context ID to check
+ * @prop: includes the context ID to check
  * @field: the field this rule refers to
  * @op: the operator the rule uses
  * @rule: pointer to the audit rule to check against
  *
  * Returns 1 if the context id matches the rule, 0 if it does not, and
  * -errno on failure.
  */
-int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *rule);
+int selinux_audit_rule_match(struct lsm_prop *prop, u32 field, u32 op, void *rule);
 
 /**
  * selinux_audit_rule_known - check to see if rule contains selinux fields.