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authorAlex Elder <elder@inktank.com>2013-02-06 13:11:38 -0600
committerAlex Elder <elder@inktank.com>2013-02-19 19:14:04 -0600
commit1ceae7ef0fd00c965a2257c6e9eb497ca91f01c7 (patch)
tree092a10e88f4503fb41495157d8ea0ad70760bdf8 /drivers/block
parentb324814e8436772cb3367b14149ba003a9954525 (diff)
downloadlinux-1ceae7ef0fd00c965a2257c6e9eb497ca91f01c7.tar.bz2
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 <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Diffstat (limited to 'drivers/block')
-rw-r--r--drivers/block/rbd.c6
1 files changed, 5 insertions, 1 deletions
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: