diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 65665c9c42c6..8b9c1734d807 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -499,7 +499,7 @@ static int rbd_header_from_disk(struct rbd_image_header *header,
 			 / sizeof (*ondisk))
 		return -EINVAL;
 	header->snapc = kmalloc(sizeof(struct ceph_snap_context) +
-				snap_count * sizeof (*ondisk),
+				snap_count * sizeof(u64),
 				gfp_flags);
 	if (!header->snapc)
 		return -ENOMEM;