Index: grub/util/grub-probe.c
===================================================================
--- grub.orig/util/grub-probe.c	2012-02-02 03:36:38.827815635 -0600
+++ grub/util/grub-probe.c	2012-02-02 03:39:22.727085000 -0600
@@ -323,6 +323,11 @@
   if (path != NULL)
     {
       grub_path = canonicalize_file_name (path);
+      if (! grub_path)
+	{
+	  grub_util_error (_("failed to get canonical path of %s"), path);
+	  return;
+	}
       device_names = grub_guess_root_devices (grub_path);
       free (grub_path);
     }