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 p212uxGT171060 for ; Mon, 28 Feb 2011 20:56:59 -0600 Received: from ipmail06.adl6.internode.on.net (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id D50751579DCA for ; Mon, 28 Feb 2011 18:59:47 -0800 (PST) Received: from ipmail06.adl6.internode.on.net (ipmail06.adl6.internode.on.net [150.101.137.145]) by cuda.sgi.com with ESMTP id pXFUWg3E4MIGTLP0 for ; Mon, 28 Feb 2011 18:59:47 -0800 (PST) Date: Tue, 1 Mar 2011 13:59:44 +1100 From: Dave Chinner Subject: Re: [PATCH] xfs: zero proper structure size for geometry calls Message-ID: <20110301025944.GG3087@dastard> References: <4D6C28A5.60905@mnsu.edu> <4D6C4DEE.6020902@sandeen.net> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <4D6C4DEE.6020902@sandeen.net> 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 , Dan Rosenberg , Eugene Teo , xfs@oss.sgi.com On Mon, Feb 28, 2011 at 07:37:50PM -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. > > Reported-by: Jeffrey Hundstad > Signed-off-by: Eric Sandeen > --- > > diff --git a/fs/xfs/linux-2.6/xfs_ioctl.c b/fs/xfs/linux-2.6/xfs_ioctl.c > index f5e2a19..34e401f 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(xfs_fsop_geom_v1_t)); I'd prefer that sizeof(fsgeo) is used here. That means if the type is changed, then memset doesn't need to be. Same for all the rest of the memset calls. Otherwise, Reviewed-by: Dave Chinner Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs