VM [KERNEL] Fix a buffer overflow in COMPARE_NAME

runtime/vm/kernel.cc

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/kernel.h"
 
 #if !defined(DART_PRECOMPILED_RUNTIME)
 namespace dart {
 
 namespace kernel {
@@ skipping 62 matching lines @@
 }
 
 
 bool CanonicalName::IsMember() {
   return IsConstructor() || IsField() || IsProcedure();
 }
 
 
 // Note the two occurrences of the parameter 'literal'.
 #define COMPARE_NAME(canonical_name, literal)                                  \
-  memcmp((canonical_name)->name()->buffer(), (literal), strlen(literal)) == 0
+  ((canonical_name)->name()->size() == strlen(literal) &&                      \
+   memcmp((canonical_name)->name()->buffer(), (literal), strlen(literal)) ==   \
+       0)
 
 bool CanonicalName::IsField() {
   // Fields with private names have the import URI of the library where they are
   // visible as the parent and the string "@fields" as the parent's parent.
   // Fields with non-private names have the string "@fields' as the parent.
   if (IsRoot()) {
     return false;
   }
   CanonicalName* kind = this->parent();
   if (IsPrivate()) {
@@ skipping 1229 matching lines @@
 
 void Program::VisitChildren(Visitor* visitor) {
   VisitList(&libraries(), visitor);
 }
 
 
 }  // namespace kernel
 
 }  // namespace dart
 #endif  // !defined(DART_PRECOMPILED_RUNTIME)