From: Alex Elder Date: Wed, 6 Feb 2013 19:11:38 +0000 (-0600) Subject: rbd: prevent bytes transferred overflow X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=1ceae7ef0fd00c965a2257c6e9eb497ca91f01c7;p=linux-beck.git rbd: prevent bytes transferred overflow In rbd_obj_read_sync(), verify the number of bytes transferred won't exceed what can be represented by a size_t before using it to indicate the number of bytes to copy to the result buffer. (The real motivation for this is to prepare for the next patch.) Signed-off-by: Alex Elder Reviewed-by: Josh Durgin --- diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 09514d9d8a97..93369a1a08e1 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -2048,6 +2048,7 @@ static int rbd_obj_read_sync(struct rbd_device *rbd_dev, struct ceph_osd_client *osdc; struct page **pages = NULL; u32 page_count; + size_t size; int ret; page_count = (u32) calc_pages_for(offset, length); @@ -2084,7 +2085,10 @@ static int rbd_obj_read_sync(struct rbd_device *rbd_dev, ret = obj_request->result; if (ret < 0) goto out; - ret = ceph_copy_from_page_vector(pages, buf, 0, obj_request->xferred); + + rbd_assert(obj_request->xferred <= (u64) SIZE_MAX); + size = (size_t) obj_request->xferred; + ret = ceph_copy_from_page_vector(pages, buf, 0, size); if (version) *version = obj_request->version; out: