diff --git a/sys/dev/disk/dm/dm_ioctl.c b/sys/dev/disk/dm/dm_ioctl.c
index 0000000..1111111 100644
--- a/sys/dev/disk/dm/dm_ioctl.c
+++ b/sys/dev/disk/dm/dm_ioctl.c
@@ -705,6 +705,10 @@
 	prop_dictionary_get_uint32(dm_dict, DM_IOCTL_MINOR, &minor);
 
 	cmd_array = prop_dictionary_get(dm_dict, DM_IOCTL_CMD_DATA);
+	if (cmd_array == NULL) {
+		dmdebug("dm_table_load_ioctl: missing cmd_data array\n");
+		return EINVAL;
+	}
 	iter = prop_array_iterator(cmd_array);
 	dm_dbg_print_flags(flags);