From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id p1EDgxEQ134547 for ; Mon, 14 Feb 2011 07:43:00 -0600 Received: from mx1.vsecurity.com (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 6407015621D7 for ; Mon, 14 Feb 2011 05:45:32 -0800 (PST) Received: from mx1.vsecurity.com (mx1.vsecurity.com [209.67.252.12]) by cuda.sgi.com with ESMTP id wEHGeEfxccVKgReC for ; Mon, 14 Feb 2011 05:45:32 -0800 (PST) Subject: [PATCH v2] xfs: prevent leaking uninitialized stack memory in FSGEOMETRY_V1 From: Dan Rosenberg In-Reply-To: <20110214114629.GA13052@dastard> References: <1297347904.13370.9.camel@dan> <20110214114629.GA13052@dastard> Date: Mon, 14 Feb 2011 08:45:28 -0500 Message-ID: <1297691128.1857.4.camel@dan> Mime-Version: 1.0 List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Dave Chinner , aelder@sgi.com, xfs-masters@oss.sgi.com, xfs@oss.sgi.com Cc: security@kernel.org, linux-kernel@vger.kernel.org, stable@kernel.org The FSGEOMETRY_V1 ioctl (and its compat equivalent) calls out to xfs_fs_geometry() with a version number of 3. This code path does not fill in the logsunit member of the passed xfs_fsop_geom_t, leading to the leaking of four bytes of uninitialized stack data to potentially unprivileged callers. v2 switches to memset() to avoid future issues if structure members change, on suggestion of Dave Chinner. Signed-off-by: Dan Rosenberg --- fs/xfs/xfs_fsops.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c index cec89dd..85668ef 100644 --- a/fs/xfs/xfs_fsops.c +++ b/fs/xfs/xfs_fsops.c @@ -53,6 +53,9 @@ xfs_fs_geometry( xfs_fsop_geom_t *geo, int new_version) { + + memset(geo, 0, sizeof(*geo)); + geo->blocksize = mp->m_sb.sb_blocksize; geo->rtextsize = mp->m_sb.sb_rextsize; geo->agblocks = mp->m_sb.sb_agblocks; _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs