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authorAl Viro <viro@zeniv.linux.org.uk>2015-03-21 20:08:18 -0400
committerSasha Levin <sasha.levin@oracle.com>2015-08-27 13:25:54 -0400
commitb03137288b2ab4e93a5c9c9bbe45e9bbc04c9b6e (patch)
parentcc25280443deb9c421eef5914ca739012bf99375 (diff)
sg_start_req(): make sure that there's not too many elements in iovec
[ Upstream commit 451a2886b6bf90e2fb378f7c46c655450fb96e81 ] unfortunately, allowing an arbitrary 16bit value means a possibility of overflow in the calculation of total number of pages in bio_map_user_iov() - we rely on there being no more than PAGE_SIZE members of sum in the first loop there. If that sum wraps around, we end up allocating too small array of pointers to pages and it's easy to overflow it in the second loop. X-Coverup: TINC (and there's no lumber cartel either) Cc: stable@vger.kernel.org # way, way back Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 07b2ea1fbf0d..b3c8aabfd687 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -1785,6 +1785,9 @@ sg_start_req(Sg_request *srp, unsigned char *cmd)
md->from_user = 0;
+ if (unlikely(iov_count > UIO_MAXIOV))
+ return -EINVAL;
if (iov_count) {
int len, size = sizeof(struct sg_iovec) * iov_count;
struct iovec *iov;