From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id p21CqkId199232 for ; Tue, 1 Mar 2011 06:52:46 -0600 Received: from mx1.vsecurity.com (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 0C6C51DDC926 for ; Tue, 1 Mar 2011 04:55:34 -0800 (PST) Received: from mx1.vsecurity.com (mx1.vsecurity.com [209.67.252.12]) by cuda.sgi.com with ESMTP id XJg645cGSLDW6V0v for ; Tue, 01 Mar 2011 04:55:34 -0800 (PST) Subject: Re: [PATCH V2] xfs: zero proper structure size for geometry calls From: Dan Rosenberg In-Reply-To: <4D6C9958.2040607@sandeen.net> References: <4D6C28A5.60905@mnsu.edu> <4D6C4DEE.6020902@sandeen.net> <4D6C9958.2040607@sandeen.net> Date: Tue, 01 Mar 2011 07:55:32 -0500 Message-ID: <1298984132.32568.3.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: Eric Sandeen Cc: Jeffrey Hundstad , Eugene Teo , xfs@oss.sgi.com On Tue, 2011-03-01 at 00:59 -0600, Eric Sandeen wrote: > commit 493f3358cb289ccf716c5a14fa5bb52ab75943e5 added: > > + memset(geo, 0, sizeof(*geo)); > > but unfortunately we're dealing with a cast pointer here, and > the caller may actually have a smaller structure on the stack. > Zeroing out more leads to stack corruption traps: > > Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: f87aca93 > > Pid: 262, comm: xfs_fsr Not tainted 2.6.38-rc6-493f3358cb2+ #1 > Call Trace: > > [] ? panic+0x50/0x150 > [] ? __stack_chk_fail+0x10/0x18 > [] ? xfs_ioc_fsgeometry_v1+0x56/0x5d [xfs] > > Fix this by zeroing out the structure in the callers, where we know > the actual size. Thanks for catching this early, and sorry for the misstep. Reviewed-by: Dan Rosenberg > > Reported-by: Jeffrey Hundstad > Signed-off-by: Eric Sandeen > --- > > V2: Use sizeof (variable) not sizeof (type) > > diff --git a/fs/xfs/linux-2.6/xfs_ioctl.c b/fs/xfs/linux-2.6/xfs_ioctl.c > index f5e2a19..871e5f0 100644 > --- a/fs/xfs/linux-2.6/xfs_ioctl.c > +++ b/fs/xfs/linux-2.6/xfs_ioctl.c > @@ -698,6 +698,7 @@ xfs_ioc_fsgeometry_v1( > xfs_fsop_geom_v1_t fsgeo; > int error; > > + memset(&fsgeo, 0, sizeof(fsgeo)); > error = xfs_fs_geometry(mp, (xfs_fsop_geom_t *)&fsgeo, 3); > if (error) > return -error; > @@ -715,6 +716,7 @@ xfs_ioc_fsgeometry( > xfs_fsop_geom_t fsgeo; > int error; > > + memset(&fsgeo, 0, sizeof(fsgeo)); > error = xfs_fs_geometry(mp, &fsgeo, 4); > if (error) > return -error; > diff --git a/fs/xfs/linux-2.6/xfs_ioctl32.c b/fs/xfs/linux-2.6/xfs_ioctl32.c > index b3486df..f25d38e 100644 > --- a/fs/xfs/linux-2.6/xfs_ioctl32.c > +++ b/fs/xfs/linux-2.6/xfs_ioctl32.c > @@ -73,6 +73,7 @@ xfs_compat_ioc_fsgeometry_v1( > xfs_fsop_geom_t fsgeo; > int error; > > + memset(&fsgeo, 0, sizeof(fsgeo)); > error = xfs_fs_geometry(mp, &fsgeo, 3); > if (error) > return -error; > diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c > index 85668ef..cec89dd 100644 > --- a/fs/xfs/xfs_fsops.c > +++ b/fs/xfs/xfs_fsops.c > @@ -53,9 +53,6 @@ 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