slsm: tree: slsm_insert_helper: fix memory leak in error path

security/slsm/tree.c

@@ -307,7 +307,7 @@ out:
 /**
  * @t: root of the tree in which the rule should be inserted
  * @path: where the rule is to be inserted, takes ownership
- * @rule: the rule, will be copied
+ * @rule: the rule, will be copied, takes ownership of references (e.g. app)
  *
  * Returns: 0 or error value
  */
@@ -316,8 +316,11 @@ static int slsm_insert_helper(struct tree_node *t, char *path,
 	char *component, *next = path + 1; /* skip leading slash */
 	struct tree_node *t_next = t;
 
-	if (!*path || *path != '/')
+	if (!*path || *path != '/') {
+		kfree(path);
+		kfree(rule->app);
 		return -EINVAL;
+	}
 
 	if (!*next) {
 		/* / is target node, we're already there */
@@ -350,7 +353,7 @@ static int slsm_insert_helper(struct tree_node *t, char *path,
 				GFP_KERNEL);
 		if (!more_children) {
 			kfree(path); /* no reference stored so far */
-			return -ENOMEM;
+			goto enomem;
 		}
 
 		t->children = more_children;
@@ -371,7 +374,7 @@ static int slsm_insert_helper(struct tree_node *t, char *path,
 		if (!t->children)
 			/* what we alloced so far is already referenced and
 			 * consistent, leave it in place */
-			return -ENOMEM;
+			goto enomem;
 
 		t->children[t->children_used] =
  			(struct tree_node){ .name = component };
@@ -392,7 +395,7 @@ insert_rule:
 				new_capacity * sizeof(*more_rules),
 				GFP_KERNEL);
 		if (!more_rules)
-			return -ENOMEM;
+			goto enomem;
 
 		t->rules = more_rules;
 		t->rules_capacity = new_capacity;
@@ -402,6 +405,10 @@ insert_rule:
 	t->rules_used++;
 
 	return 0;
+
+enomem:
+	kfree(rule->app);
+	return -ENOMEM;
 }