--- a/hotspot/src/share/vm/runtime/os.cpp	Fri Nov 16 09:59:08 2012 +0100
+++ b/hotspot/src/share/vm/runtime/os.cpp	Fri Nov 16 09:19:12 2012 -0500
@@ -582,7 +582,9 @@
     // if NULL is returned the calling functions assume out of memory.
     size = 1;
   }
-
+  if (size > size + space_before + space_after) { // Check for rollover.
+    return NULL;
+  }
   NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
   u_char* ptr = (u_char*)::malloc(size + space_before + space_after);