All of lore.kernel.org
 help / color / mirror / Atom feed
From: Dan Rosenberg <drosenberg@vsecurity.com>
To: Eric Sandeen <sandeen@sandeen.net>
Cc: Jeffrey Hundstad <jeffrey.hundstad@mnsu.edu>,
	Eugene Teo <eugeneteo@kernel.org>,
	xfs@oss.sgi.com
Subject: Re: [PATCH V2] xfs: zero proper structure size for geometry calls
Date: Tue, 01 Mar 2011 07:55:32 -0500	[thread overview]
Message-ID: <1298984132.32568.3.camel@dan> (raw)
In-Reply-To: <4D6C9958.2040607@sandeen.net>

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:
> 
> [<c12991ac>] ? panic+0x50/0x150
> [<c102ed71>] ? __stack_chk_fail+0x10/0x18
> [<f87aca93>] ? 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 <drosenberg@vsecurity.com>

> 
> Reported-by: Jeffrey Hundstad <jeffrey.hundstad@mnsu.edu>
> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
> ---
> 
> 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

  reply	other threads:[~2011-03-01 12:52 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-02-28 22:58 kernel panic - stack-protector: kernel stack is corrupted in: f87aca93 Jeffrey Hundstad
2011-03-01  0:00 ` Eric Sandeen
2011-03-01  1:03   ` Jeffrey Hundstad
2011-03-01  1:32     ` Eric Sandeen
2011-03-01  2:57       ` Dave Chinner
2011-03-01  1:37 ` [PATCH] xfs: zero proper structure size for geometry calls Eric Sandeen
2011-03-01  2:59   ` Dave Chinner
2011-03-01  3:01     ` Eric Sandeen
2011-03-01  6:59   ` [PATCH V2] " Eric Sandeen
2011-03-01 12:55     ` Dan Rosenberg [this message]
2011-03-01 15:36       ` Jeffrey Hundstad
2011-03-01 15:49         ` Eric Sandeen
2011-03-01 17:50           ` [PATCH, V3 (sort of)] " Alex Elder
2011-03-01 18:18             ` Eric Sandeen
2011-03-01 21:40               ` Jeffrey Hundstad
2011-03-02  0:02             ` Dave Chinner

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1298984132.32568.3.camel@dan \
    --to=drosenberg@vsecurity.com \
    --cc=eugeneteo@kernel.org \
    --cc=jeffrey.hundstad@mnsu.edu \
    --cc=sandeen@sandeen.net \
    --cc=xfs@oss.sgi.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.