From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758597Ab1DZVNk (ORCPT ); Tue, 26 Apr 2011 17:13:40 -0400 Received: from mga11.intel.com ([192.55.52.93]:61741 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758550Ab1DZVNg (ORCPT ); Tue, 26 Apr 2011 17:13:36 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.64,270,1301900400"; d="scan'208";a="684326737" From: Andi Kleen References: <20110426212.641772347@firstfloor.org> In-Reply-To: <20110426212.641772347@firstfloor.org> To: drosenberg@vsecurity.com, ak@linux.intel.com, eugeneteo@kernel.org, aelder@sgi.com, gregkh@suse.de, linux-kernel@vger.kernel.org, stable@kernel.org, tim.bird@am.sony.com Subject: [PATCH] [8/106] xfs: prevent leaking uninitialized stack memory in FSGEOMETRY_V1 Message-Id: <20110426211246.2E1863E1887@tassilo.jf.intel.com> Date: Tue, 26 Apr 2011 14:12:46 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.35-longterm review patch. If anyone has any objections, please let me know. ------------------ From: Dan Rosenberg commit c4d0c3b097f7584772316ee4d64a09fe0e4ddfca upstream. 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 Signed-off-by: Andi Kleen Reviewed-by: Eugene Teo Signed-off-by: Alex Elder Signed-off-by: Greg Kroah-Hartman --- fs/xfs/xfs_fsops.c | 3 +++ 1 file changed, 3 insertions(+) Index: linux-2.6.35.y/fs/xfs/xfs_fsops.c =================================================================== --- linux-2.6.35.y.orig/fs/xfs/xfs_fsops.c +++ linux-2.6.35.y/fs/xfs/xfs_fsops.c @@ -57,6 +57,9 @@ 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;