diff --git a/ChangeLog b/ChangeLog
index 18c2abeac..34bc31bf9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2010-05-27  Colin Watson  <cjwatson@ubuntu.com>
+
+	* kern/emu/misc.c (canonicalize_file_name): realpath can still
+	return NULL for various reasons even if it has a maximum-length
+	buffer: for example, there might be a symlink loop, or the path
+	might exceed PATH_MAX.  If this happens, return NULL.
+
 2010-05-27  Robert Millan  <rmh@gnu.org>
 
 	* util/grub-mkconfig_lib.in (prepare_grub_to_access_device): Insert
diff --git a/kern/emu/misc.c b/kern/emu/misc.c
index a3ccb3076..9437169e0 100644
--- a/kern/emu/misc.c
+++ b/kern/emu/misc.c
@@ -185,7 +185,8 @@ canonicalize_file_name (const char *path)
   char *ret;
 #ifdef PATH_MAX
   ret = xmalloc (PATH_MAX);
-  (void) realpath (path, ret);
+  if (!realpath (path, ret))
+    return NULL;
 #else
   ret = realpath (path, NULL);
 #endif