[wasm] Validate the length of strings before validating the string.

test/unittests/wasm/module-decoder-unittest.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "test/unittests/test-utils.h"
 
 #include "src/handles.h"
 #include "src/objects-inl.h"
 #include "src/wasm/module-decoder.h"
 #include "src/wasm/wasm-macro-gen.h"
@@ skipping 1005 matching lines @@
                               ONE_EMPTY_BODY};
   ModuleResult result = DecodeModule(data, data + arraysize(data));
   EXPECT_OK(result);
 
   EXPECT_EQ(1, result.val->functions.size());
   EXPECT_EQ(1, result.val->export_table.size());
 
   if (result.val) delete result.val;
 }
 
+TEST_F(WasmModuleVerifyTest, ExportNameWithInvalidStringLength) {
+  static const byte data[] = {// signatures
+                              SIGNATURES_SECTION_VOID_VOID,
+                              ONE_EMPTY_FUNCTION,
+                              SECTION(EXPORT_TABLE, 12),
+                              1,                // exports
+                              FUNC_INDEX(0),    // --
+                              NAME_LENGTH(84),  // invalid string length
+                              'e',              // --
+                              ONE_EMPTY_BODY};
+
+  EXPECT_FAILURE(data);
+}
+
 TEST_F(WasmModuleVerifyTest, ExportTableTwo) {
   static const byte data[] = {// signatures
                               SIGNATURES_SECTION_VOID_VOID,
                               ONE_EMPTY_FUNCTION,
                               SECTION(EXPORT_TABLE, 12),
                               2,              // exports
                               FUNC_INDEX(0),  // --
                               NAME_LENGTH(4),
                               'n',
                               'a',
@@ skipping 180 matching lines @@
       NO_LOCAL_NAMES,  // --
       FOO_STRING,
       NO_LOCAL_NAMES,  // --
   };
   EXPECT_VERIFIES(data);
 }
 
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8