diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 8c420f178603..d35e4c991e38 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1738,7 +1738,7 @@ static int process_checks(struct r1bio *r1_bio)
 				s = sbio->bi_io_vec[j].bv_page;
 				if (memcmp(page_address(p),
 					   page_address(s),
-					   PAGE_SIZE))
+					   sbio->bi_io_vec[j].bv_len))
 					break;
 			}
 		} else
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 3540316886f2..fff782189e48 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1821,7 +1821,7 @@ static void sync_request_write(struct mddev *mddev, struct r10bio *r10_bio)
 			for (j = 0; j < vcnt; j++)
 				if (memcmp(page_address(fbio->bi_io_vec[j].bv_page),
 					   page_address(tbio->bi_io_vec[j].bv_page),
-					   PAGE_SIZE))
+					   fbio->bi_io_vec[j].bv_len))
 					break;
 			if (j == vcnt)
 				continue;