From patchwork Fri Oct 29 01:40:55 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andy Grover X-Patchwork-Id: 69540 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 67657B70DF for ; Fri, 29 Oct 2010 12:42:40 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759087Ab0J2Bmh (ORCPT ); Thu, 28 Oct 2010 21:42:37 -0400 Received: from rcsinet10.oracle.com ([148.87.113.121]:44289 "EHLO rcsinet10.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755651Ab0J2Bmf (ORCPT ); Thu, 28 Oct 2010 21:42:35 -0400 Received: from rcsinet15.oracle.com (rcsinet15.oracle.com [148.87.113.117]) by rcsinet10.oracle.com (Switch-3.4.2/Switch-3.4.2) with ESMTP id o9T1ftfK030894 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Fri, 29 Oct 2010 01:41:57 GMT Received: from acsmt353.oracle.com (acsmt353.oracle.com [141.146.40.153]) by rcsinet15.oracle.com (Switch-3.4.2/Switch-3.4.1) with ESMTP id o9T0wPRt011204; Fri, 29 Oct 2010 01:41:55 GMT Received: from abhmt012.oracle.com by acsmt355.oracle.com with ESMTP id 732721841288316481; Thu, 28 Oct 2010 18:41:21 -0700 Received: from lute.us.oracle.com (/139.185.48.5) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 28 Oct 2010 18:41:20 -0700 From: Andy Grover To: netdev@vger.kernel.org Cc: rds-devel@oss.oracle.com, Linus Torvalds Subject: [PATCH 1/5] net: fix rds_iovec page count overflow Date: Thu, 28 Oct 2010 18:40:55 -0700 Message-Id: <1288316459-4679-2-git-send-email-andy.grover@oracle.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1288316459-4679-1-git-send-email-andy.grover@oracle.com> References: <1288316459-4679-1-git-send-email-andy.grover@oracle.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Linus Torvalds As reported by Thomas Pollet, the rdma page counting can overflow. We get the rdma sizes in 64-bit unsigned entities, but then limit it to UINT_MAX bytes and shift them down to pages (so with a possible "+1" for an unaligned address). So each individual page count fits comfortably in an 'unsigned int' (not even close to overflowing into signed), but as they are added up, they might end up resulting in a signed return value. Which would be wrong. Catch the case of tot_pages turning negative, and return the appropriate error code. Reported-by: Thomas Pollet Signed-off-by: Linus Torvalds Signed-off-by: Andy Grover --- net/rds/rdma.c | 7 +++++++ 1 files changed, 7 insertions(+), 0 deletions(-) diff --git a/net/rds/rdma.c b/net/rds/rdma.c index 1a41deb..0df02c8 100644 --- a/net/rds/rdma.c +++ b/net/rds/rdma.c @@ -502,6 +502,13 @@ static int rds_rdma_pages(struct rds_rdma_args *args) return -EINVAL; tot_pages += nr_pages; + + /* + * nr_pages for one entry is limited to (UINT_MAX>>PAGE_SHIFT)+1, + * so tot_pages cannot overflow without first going negative. + */ + if ((int)tot_pages < 0) + return -EINVAL; } return tot_pages;