From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-Id: <20111102221454.703920975@clark.kroah.org> Date: Wed, 02 Nov 2011 15:14:16 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Xiaotian Feng , Jens Axboe , Dan Carpenter Subject: [050/107] block: check for proper length of iov entries earlier in blk_rq_map_user_iov() In-Reply-To: <20111102221600.GA26650@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: 2.6.32-longterm review patch. If anyone has any objections, please let us know. ------------------ From: Xiaotian Feng commit 5478755616ae2ef1ce144dded589b62b2a50d575 upstream. commit 9284bcf checks for proper length of iov entries in blk_rq_map_user_iov(). But if the map is unaligned, kernel will break out the loop without checking for the proper length. So we need to check the proper length before the unalign check. Signed-off-by: Xiaotian Feng Signed-off-by: Jens Axboe Cc: Dan Carpenter Signed-off-by: Greg Kroah-Hartman --- block/blk-map.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/block/blk-map.c +++ b/block/blk-map.c @@ -201,12 +201,13 @@ int blk_rq_map_user_iov(struct request_q for (i = 0; i < iov_count; i++) { unsigned long uaddr = (unsigned long)iov[i].iov_base; + if (!iov[i].iov_len) + return -EINVAL; + if (uaddr & queue_dma_alignment(q)) { unaligned = 1; break; } - if (!iov[i].iov_len) - return -EINVAL; } if (unaligned || (q->dma_pad_mask & len) || map_data)