Check double array bounds in HasElementImpl.

src/elements.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 826 matching lines @@
     if (key < static_cast<uint32_t>(length)) {
       FixedDoubleArray::cast(obj->elements())->set_the_hole(key);
     }
     return obj->GetHeap()->true_value();
   }
 
   static bool HasElementImpl(Object* receiver,
                              JSObject* holder,
                              uint32_t key,
                              FixedDoubleArray* backing_store) {
-    return !backing_store->is_the_hole(key);
+    return key < static_cast<uint32_t>(backing_store->length()) &&
+        !backing_store->is_the_hole(key);
   }
 };
 
 
 // Super class for all external element arrays.
 template<typename ExternalElementsAccessorSubclass,
          ElementsKind Kind>
 class ExternalElementsAccessor
     : public ElementsAccessorBase<ExternalElementsAccessorSubclass,
                                   ElementsKindTraits<Kind> > {
@@ skipping 554 matching lines @@
   if (!maybe_obj->To(&new_backing_store)) return maybe_obj;
   new_backing_store->set(0, length);
   { MaybeObject* result = array->SetContent(new_backing_store);
     if (result->IsFailure()) return result;
   }
   return array;
 }
 
 
 } }  // namespace v8::internal