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From: Eugene Teo <>
To: Dan Rosenberg <>
Cc:,,,,,, Eugene Teo <>
Subject: Re: [Security] [PATCH] xfs: prevent leaking uninitialized stack memory in FSGEOMETRY_V1
Date: Mon, 14 Feb 2011 16:41:46 +0800	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <1297347904.13370.9.camel@dan>

On Thu, Feb 10, 2011 at 10:25 PM, Dan Rosenberg
<> wrote:
> 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.  Since all other members are filled in all code
> paths and there are no padding bytes in this structure, it's safe to
> avoid an expensive memset() in favor of just clearing this one field.
> Signed-off-by: Dan Rosenberg <>

There are three callers to xfs_fs_geometry() with version number 3 and
4. I don't see any for version number 2, so this looks fine.

Reviewed-by: Eugene Teo <>

Thanks, Eugene

  reply	other threads:[~2011-02-14  8:41 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-02-10 14:25 Dan Rosenberg
2011-02-14  8:41 ` Eugene Teo [this message]
2011-02-14 11:46 ` Dave Chinner
2011-02-14 13:45   ` [PATCH v2] " Dan Rosenberg
2011-02-14 23:39     ` Eugene Teo

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