--- device-mapper.orig/lib/ioctl/libdm-iface.c	2007-08-02 15:58:25.000000000 -0700
+++ device-mapper/lib/ioctl/libdm-iface.c	2007-08-02 15:59:59.000000000 -0700
@@ -321,6 +321,9 @@
 {
 	struct target *t, *n;
 
+	if(!dmt)
+		return; /* NULL pointer would cause segfault */
+	
 	for (t = dmt->head; t; t = n) {
 		n = t->next;
 		dm_free(t->params);