8034926: Attribute classes properly

Summary: Add check to prevent underflow
Reviewed-by: coleenp, ahgross

src/share/vm/classfile/classFileParser.cpp

 /*
- * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -2777,6 +2777,11 @@ void ClassFileParser::parse_classfile_bootstrap_methods_attribute(u4 attribute_b
                      "Short length on BootstrapMethods in class file %s",
                      CHECK);
 
+  guarantee_property(attribute_byte_length > sizeof(u2),
+                     "Invalid BootstrapMethods attribute length %u in class file %s",
+                     attribute_byte_length,
+                     CHECK);
+
   // The attribute contains a counted array of counted tuples of shorts,
   // represending bootstrap specifiers:
   //    length*{bootstrap_method_index, argument_count*{argument_index}}