diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index c8c27d23bb456ec7d0dc33b8b334abcbd61bdc7d..2b00359e4825e749c3c64ceb700c26ba4b7521ce 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -573,7 +573,7 @@ static void list_version_get_needed(struct target_type *tt, void *needed_param)
     size_t *needed = needed_param;
 
     *needed += sizeof(struct dm_target_versions);
-    *needed += strlen(tt->name);
+    *needed += strlen(tt->name) + 1;
     *needed += ALIGN_MASK;
 }
 
@@ -628,7 +628,7 @@ static int list_versions(struct file *filp, struct dm_ioctl *param, size_t param
 	iter_info.old_vers = NULL;
 	iter_info.vers = vers;
 	iter_info.flags = 0;
-	iter_info.end = (char *)vers+len;
+	iter_info.end = (char *)vers + needed;
 
 	/*
 	 * Now loop through filling out the names & versions.