ext/standard: validate sort flags when selecting unstable compare function

Author: arshidkv12

ext/standard/array.c

@@ -4916,6 +4916,12 @@ PHP_FUNCTION(array_unique)
 
 	cmp = php_get_data_compare_func_unstable(sort_type, false);
 
+	if(cmp == NULL){
+		zend_argument_value_error(
+			2, "must be one of SORT_REGULAR, SORT_NUMERIC, SORT_STRING, or SORT_LOCALE_STRING");
+		RETURN_THROWS();
+	}
+
 	bool in_place = zend_may_modify_arg_in_place(array);
 	if (in_place) {
 		RETVAL_ARR(Z_ARRVAL_P(array));
@@ -5990,7 +5996,20 @@ PHP_FUNCTION(array_multisort)
 			/* We see the next array, so we update the sort flags of
 			 * the previous array and reset the sort flags. */
 			if (i > 0) {
-				func[num_arrays - 1] = php_get_data_compare_func_unstable(sort_type, sort_order != PHP_SORT_ASC);
+				bucket_compare_func_t cmp =
+					php_get_data_compare_func_unstable(
+						sort_type, sort_order != PHP_SORT_ASC
+					);
+
+				if (cmp == NULL) {
+					zend_argument_value_error(
+						2,
+						"must be one of SORT_REGULAR, SORT_NUMERIC, SORT_STRING, or SORT_LOCALE_STRING"
+					);
+					RETURN_THROWS();
+				}
+
+				func[num_arrays - 1] = cmp;
 				sort_order = PHP_SORT_ASC;
 				sort_type = PHP_SORT_REGULAR;
 			}
@@ -6060,7 +6079,20 @@ PHP_FUNCTION(array_multisort)
 	}
 
 	/* Take care of the last array sort flags. */
-	func[num_arrays - 1] = php_get_data_compare_func_unstable(sort_type, sort_order != PHP_SORT_ASC);
+	bucket_compare_func_t cmp =
+		php_get_data_compare_func_unstable(
+			sort_type, sort_order != PHP_SORT_ASC
+		);
+
+	if (cmp == NULL) {
+		zend_argument_value_error(
+			2,
+			"must be one of SORT_REGULAR, SORT_NUMERIC, SORT_STRING, or SORT_LOCALE_STRING"
+		);
+		RETURN_THROWS();
+	}
+
+	func[num_arrays - 1] = cmp;
 	bucket_compare_func_t *old_multisort_func = ARRAYG(multisort_func);
 	ARRAYG(multisort_func) = func;