From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932880Ab1DMQ12 (ORCPT ); Wed, 13 Apr 2011 12:27:28 -0400 Received: from kroah.org ([198.145.64.141]:52782 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932355Ab1DMQMt (ORCPT ); Wed, 13 Apr 2011 12:12:49 -0400 X-Mailbox-Line: From gregkh@clark.kroah.org Wed Apr 13 09:10:44 2011 Message-Id: <20110413161044.363600104@clark.kroah.org> User-Agent: quilt/0.48-16.4 Date: Wed, 13 Apr 2011 09:09:41 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Dan Rosenberg , Alex Elder Subject: [18/71] xfs: prevent leaking uninitialized stack memory in FSGEOMETRY_V1 In-Reply-To: <20110413161106.GA20405@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.33-longterm review patch. If anyone has any objections, please let us 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 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(+) --- a/fs/xfs/xfs_fsops.c +++ b/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;