diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index 1b3fe99b83a6..48bb4e1ea1e7 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -484,9 +484,10 @@ int sg_scsi_ioctl(struct request_queue *q, struct gendisk *disk, fmode_t mode,
 		break;
 	}
 
-	if (bytes && blk_rq_map_kern(q, rq, buffer, bytes, GFP_NOIO)) {
-		err = DRIVER_ERROR << 24;
-		goto error;
+	if (bytes) {
+		err = blk_rq_map_kern(q, rq, buffer, bytes, GFP_NOIO);
+		if (err)
+			goto error;
 	}
 
 	blk_execute_rq(disk, rq, 0);