Set umask to 0077 before creating disk images

bin/xen-create-image

@@ -2573,9 +2573,17 @@ sub createLoopbackImages
             $image_cmd = "dd if=/dev/zero of=$disk bs=$size count=1024";
         }
 
+        # Set the umask so that the images are not world readable.
+        my $oldumask = umask;
+        umask(0077);
+
+	# run the image creation command
         runCommand($image_cmd);
         logprint("Done\n");
 
+        # Reset the umask to the previous value
+        umask($oldumask);
+
         if ( !-e $disk )
         {
             logprint("The partition image creation failed to create $disk.\n");