Limit the constructed string size in String.prototype.repeat (#3066)

This patch fixes #3063.

JerryScript-DCO-1.0-Signed-off-by: Robert Fancsik frobert@inf.u-szeged.hu

jerry-core/ecma/base/ecma-globals.h

@@ -1348,6 +1348,11 @@ typedef enum
 #define ECMA_GET_DIRECT_STRING_VALUE(string_p) \
   (((uintptr_t) (string_p)) >> ECMA_DIRECT_STRING_SHIFT)
 
+/**
+ * Maximum number of bytes that a long-utf8-string is able to store
+ */
+#define ECMA_STRING_SIZE_LIMIT UINT32_MAX
+
 typedef enum
 {
   ECMA_STRING_CONTAINER_HEAP_UTF8_STRING, /**< actual data is on the heap as an utf-8 (cesu8) string

jerry-core/ecma/builtin-objects/ecma-builtin-string-prototype.c

@@ -1913,6 +1913,12 @@ ecma_builtin_string_prototype_object_repeat (ecma_string_t *original_string_p, /
   }
 
   lit_utf8_size_t size = ecma_string_get_utf8_size (original_string_p);
+
+  if ((uint32_t) length >= (ECMA_STRING_SIZE_LIMIT / size))
+  {
+    return ecma_raise_range_error (ECMA_ERR_MSG ("Invalid string length"));
+  }
+
   lit_utf8_size_t total_size = size * (lit_utf8_size_t) length;
 
   JMEM_DEFINE_LOCAL_ARRAY (str_buffer, total_size, lit_utf8_byte_t);