From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Serge E. Hallyn" <serge-A9i7LUbDfNHQT0dZR+AlfA@public.gmane.org>
Subject: Re: [PATCH 04/11] Add backend support for suboridnate uids and gids
Date: Wed, 23 Jan 2013 18:22:06 +0000
Message-ID: <20130123182206.GA4468@mail.hallyn.com>
References: <87d2wxshu0.fsf@xmission.com>
 <87liblr344.fsf@xmission.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Return-path: <containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org>
Content-Disposition: inline
In-Reply-To: <87liblr344.fsf-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
List-Unsubscribe: <https://lists.linuxfoundation.org/mailman/options/containers>,
	<mailto:containers-request-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org?subject=unsubscribe>
List-Archive: <http://lists.linuxfoundation.org/pipermail/containers/>
List-Post: <mailto:containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org>
List-Help: <mailto:containers-request-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org?subject=help>
List-Subscribe: <https://lists.linuxfoundation.org/mailman/listinfo/containers>,
	<mailto:containers-request-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org?subject=subscribe>
Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org
Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org
To: "Eric W. Biederman" <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
Cc: Linux Containers <containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org>, Pkg-shadow-devel-XbBxUvOt3X2LieD7tvxI8l/i77bcL1HB@public.gmane.org, "Michael Kerrisk (man-pages)" <mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>, Nicolas =?iso-8859-1?Q?Fran=E7ois?= <nicolas.francois-Fa7rcPG4DJn7nK0/Xc0eeg@public.gmane.org>
List-Id: containers.vger.kernel.org

Quoting Eric W. Biederman (ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org):
> +static void *subordinate_parse (const char *line)
> +{
> +	static struct subordinate_range range;
> +	char rangebuf[1024];
> +	int i;
> +	char *cp;
> +	char *fields[NFIELDS];
> +
> +	/*
> +	 * Copy the string to a temporary buffer so the substrings can
> +	 * be modified to be NULL terminated.
> +	 */
> +	if (strlen (line) >= sizeof rangebuf)
> +		return NULL;	/* fail if too long */
> +	strcpy (rangebuf, line);
> +
> +	/*
> +	 * Save a pointer to the start of each colon separated
> +	 * field.  The fields are converted into NUL terminated strings.
> +	 */
> +
> +	for (cp = rangebuf, i = 0; (i < NFIELDS) && (NULL != cp); i++) {
> +		fields[i] = cp;
> +		while (('\0' != *cp) && (':' != *cp)) {
> +			cp++;
> +		}
> +
> +		if ('\0' != *cp) {
> +			*cp = '\0';
> +			cp++;
> +		} else {
> +			cp = NULL;
> +		}
> +	}
> +
> +	/*
> +	 * There must be exactly NFIELDS colon separated fields or
> +	 * the entry is invalid.  Also, fields must be non-blank.
> +	 */
> +	if (i != NFIELDS || *fields[0] == '\0' || *fields[1] == '\0' || *fields[2] == '\0')
> +		return NULL;
> +	range.owner = fields[0];
> +	if (getulong (fields[1], &range.start) == 0)
> +		return NULL;
> +	if (getulong (fields[2], &range.count) == 0)
> +		return NULL;
> +
> +	return &range;

This function worries me, because you're returning local contents (both range
itself, and range.owner).

-serge