From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933003Ab1DNSf6 (ORCPT ); Thu, 14 Apr 2011 14:35:58 -0400 Received: from mail.windriver.com ([147.11.1.11]:37340 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932558Ab1DNRpb (ORCPT ); Thu, 14 Apr 2011 13:45:31 -0400 From: Paul Gortmaker To: stable@kernel.org, linux-kernel@vger.kernel.org Cc: stable-review@kernel.org, Jens Axboe , Paul Gortmaker Subject: [34-longterm 017/209] block: take care not to overflow when calculating total iov length Date: Thu, 14 Apr 2011 13:40:47 -0400 Message-Id: <1302803039-9400-18-git-send-email-paul.gortmaker@windriver.com> X-Mailer: git-send-email 1.7.4.4 In-Reply-To: <1302803039-9400-1-git-send-email-paul.gortmaker@windriver.com> References: <1302803039-9400-1-git-send-email-paul.gortmaker@windriver.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jens Axboe ===================================================================== | This is a commit scheduled for the next v2.6.34 longterm release. | | If you see a problem with using this for longterm, please comment.| ===================================================================== commit 9f864c80913467312c7b8690e41fb5ebd1b50e92 upstream. Reported-by: Dan Rosenberg Signed-off-by: Jens Axboe Signed-off-by: Paul Gortmaker --- block/scsi_ioctl.c | 34 ++++++++++++++++++++++++---------- 1 files changed, 24 insertions(+), 10 deletions(-) diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c index a8b5a10..4f4230b 100644 --- a/block/scsi_ioctl.c +++ b/block/scsi_ioctl.c @@ -321,33 +321,47 @@ static int sg_io(struct request_queue *q, struct gendisk *bd_disk, if (hdr->iovec_count) { const int size = sizeof(struct sg_iovec) * hdr->iovec_count; size_t iov_data_len; - struct sg_iovec *iov; + struct sg_iovec *sg_iov; + struct iovec *iov; + int i; - iov = kmalloc(size, GFP_KERNEL); - if (!iov) { + sg_iov = kmalloc(size, GFP_KERNEL); + if (!sg_iov) { ret = -ENOMEM; goto out; } - if (copy_from_user(iov, hdr->dxferp, size)) { - kfree(iov); + if (copy_from_user(sg_iov, hdr->dxferp, size)) { + kfree(sg_iov); ret = -EFAULT; goto out; } + /* + * Sum up the vecs, making sure they don't overflow + */ + iov = (struct iovec *) sg_iov; + iov_data_len = 0; + for (i = 0; i < hdr->iovec_count; i++) { + if (iov_data_len + iov[i].iov_len < iov_data_len) { + kfree(sg_iov); + ret = -EINVAL; + goto out; + } + iov_data_len += iov[i].iov_len; + } + /* SG_IO howto says that the shorter of the two wins */ - iov_data_len = iov_length((struct iovec *)iov, - hdr->iovec_count); if (hdr->dxfer_len < iov_data_len) { - hdr->iovec_count = iov_shorten((struct iovec *)iov, + hdr->iovec_count = iov_shorten(iov, hdr->iovec_count, hdr->dxfer_len); iov_data_len = hdr->dxfer_len; } - ret = blk_rq_map_user_iov(q, rq, NULL, iov, hdr->iovec_count, + ret = blk_rq_map_user_iov(q, rq, NULL, sg_iov, hdr->iovec_count, iov_data_len, GFP_KERNEL); - kfree(iov); + kfree(sg_iov); } else if (hdr->dxfer_len) ret = blk_rq_map_user(q, rq, NULL, hdr->dxferp, hdr->dxfer_len, GFP_KERNEL); -- 1.7.4.4