diff --git a/block/blk-map.c b/block/blk-map.c
index 5d5dbe4..e663ac2 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -201,12 +201,13 @@
 	for (i = 0; i < iov_count; i++) {
 		unsigned long uaddr = (unsigned long)iov[i].iov_base;
 
+		if (!iov[i].iov_len)
+			return -EINVAL;
+
 		if (uaddr & queue_dma_alignment(q)) {
 			unaligned = 1;
 			break;
 		}
-		if (!iov[i].iov_len)
-			return -EINVAL;
 	}
 
 	if (unaligned || (q->dma_pad_mask & len) || map_data)