From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1756731Ab0ITPzO (ORCPT <rfc822;w@1wt.eu>);
	Mon, 20 Sep 2010 11:55:14 -0400
Received: from cantor.suse.de ([195.135.220.2]:49124 "EHLO mx1.suse.de"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1751844Ab0ITPzM (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
	Mon, 20 Sep 2010 11:55:12 -0400
Subject: Re: [PATCH 10/14] scsi: osd: fix device_register() error handling
From: James Bottomley <James.Bottomley@suse.de>
To: Boaz Harrosh <bharrosh@panasas.com>
Cc: Greg KH <gregkh@suse.de>, Dan Carpenter <error27@gmail.com>,
        Vasiliy Kulikov <segooon@gmail.com>, kernel-janitors@vger.kernel.org,
        Benny Halevy <bhalevy@panasas.com>, Tejun Heo <tj@kernel.org>,
        Arnd Bergmann <arnd@arndb.de>, osd-dev@open-osd.org,
        linux-scsi@vger.kernel.org, cornelia.huck@de.ibm.com,
        linux-kernel@vger.kernel.org, Kay Sievers <kay.sievers@vrfy.org>
In-Reply-To: <4C9780D5.8000804@panasas.com>
References: <1284900907-24621-1-git-send-email-segooon@gmail.com>
	 <20100919142653.GF6236@bicker> <1284983897.2973.11.camel@mulgrave.site>
	 <20100920151029.GA25386@suse.de>  <20100920151317.GA25506@suse.de>
	 <1284996062.2973.85.camel@mulgrave.site>  <4C9780D5.8000804@panasas.com>
Content-Type: text/plain; charset="UTF-8"
Date: Mon, 20 Sep 2010 10:55:06 -0500
Message-ID: <1284998106.2973.125.camel@mulgrave.site>
Mime-Version: 1.0
X-Mailer: Evolution 2.30.1.2 
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Mon, 2010-09-20 at 17:42 +0200, Boaz Harrosh wrote:
> I think I have a compromise. If it is indeed the dev_set_name() leak
> then we can just deallocate the name on the error return path. Therefore
> any drivers that have the device embedded and rely on it been freed without
> calling _put will be fine as before. And these calling _put will be fine
> as well.
> 
> See below
> Boaz
> ---
> git diff --stat -p -M drivers/base/core.c
>  drivers/base/core.c |    1 +
>  1 files changed, 1 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index d1b2c9a..054fac2 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -1068,6 +1068,7 @@ done:
>  	if (parent)
>  		put_device(parent);
>  name_error:
> +	kfree(dev->kobj.name);
>  	kfree(dev->p);
>  	dev->p = NULL;
>  	goto done;

That's not really good enough ... it will result in a double free
because the final put (if there is one) will free the name again.

This would work, but it feels a bit wrong to be poking at the kobject
from within the driver core ... perhaps a kobject_free_name() call might
be better?

James

---

diff --git a/drivers/base/core.c b/drivers/base/core.c
index d1b2c9a..88ffaca 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -1067,6 +1067,8 @@ done:
 	cleanup_device_parent(dev);
 	if (parent)
 		put_device(parent);
+	kfree(dev->kobj.name);
+	dev->kobj.name = NULL;
 name_error:
 	kfree(dev->p);
 	dev->p = NULL;