Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Tue, 20 Jun 2023 06:43:31 -0700
From:   Ira Weiny <ira.weiny@intel.com>
To:     Jiasheng Jiang <jiasheng@iscas.ac.cn>, <dan.j.williams@intel.com>,
        <vishal.l.verma@intel.com>, <dave.jiang@intel.com>,
        <ira.weiny@intel.com>, <oohall@gmail.com>,
        <aneesh.kumar@linux.ibm.com>
CC:     <nvdimm@lists.linux.dev>, <linux-kernel@vger.kernel.org>,
        Jiasheng Jiang <jiasheng@iscas.ac.cn>
Subject: Re: [PATCH] libnvdimm/of_pmem: Add check and kfree for kstrdup
Message-ID: <6491ad03658ff_28e7294a5@iweiny-mobl.notmuch>
References: <20230619033623.11044-1-jiasheng@iscas.ac.cn>
Content-Type: text/plain; charset="us-ascii"
Content-Disposition: inline
In-Reply-To: <20230619033623.11044-1-jiasheng@iscas.ac.cn>
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?sDkd815OyUBThUPoHwn771XYtbfeufAV75MebyeA8Bg4jbQd0TinDKpt2Lk/?=
 =?us-ascii?Q?8PqxvUxWnNpF1a3/WKWXv8sfT+UJBhTTGsYTXrERdhshjDuGehr2vv6p2DnX?=
 =?us-ascii?Q?gs9t+u0+jEu2XuiIXU2EC1ETWt+S7At3d+0W5s5e+F7h6XcRWFCMRRj1V45A?=
 =?us-ascii?Q?70hUJ9pbkW/RK6+9TaddNHM2nFiKnPIm2IqY4lz9WASkYBMLvfE115CnxIL3?=
 =?us-ascii?Q?ncLlXc5Y6Vn7cDP2OmarxPfwgHeEwz1G7Nav19Sbr+rPTqu4cw3nMEhyeZ6A?=
 =?us-ascii?Q?t5CKASaabIYfvs/znJ2AdHe16c64B//kYv4p0Hu6xlkg+cTaoCAV+IK37BIK?=
 =?us-ascii?Q?OrIwTi5W5Kw5YMe0do+SRgHfkJ1DYdNIIcGvlYYPpln9fqlFQvlvDQ4d5sFg?=
 =?us-ascii?Q?8xa8B7vMEAw+JC5wxYaRcTF5yJUd4540/SQg12y+ZHoIHlQBBwzQmoLzWgSs?=
 =?us-ascii?Q?2otYjLtZckMCSzNaRSVsIeBg07RbWiAJewIKh17Oz7yMhEfOcXvbvf1QToaq?=
 =?us-ascii?Q?u2eT/n/PrTpOSx9WfDdlWpSEGdy37rrv0u6SFTsa7jIcLJaco8aQg/QhS4sV?=
 =?us-ascii?Q?A9K11f1MTnXZeRG/rNbDALyL5EM/2i+705Oqed5FLkA6S9FBbFEOHq8s26ls?=
 =?us-ascii?Q?UWFOQ9w0FRl9gr7jaLuduVhPtJnmiHrr5KB+Xr8EbWJqyXHscqrcW0ArG3v8?=
 =?us-ascii?Q?AzJ1zI98XjzrNXHncXPqo26HLvTeEWwc16q5DQHRg1ALFw4Erzb/TFo5LA6s?=
 =?us-ascii?Q?KszyYJkAIhXEm/1dPgfBKEXy7Ri6D/RScU5t9O24nsLykxAmWj+B/t23tR41?=
 =?us-ascii?Q?At3/FZRuLanAfiGxs7oJ/OxMqkmUiYe7Ue7JF+ODFO2NjacG8t72NxbbnEd8?=
 =?us-ascii?Q?Te0O+nC75NgRvN/9ZgGgUndN0UOjutzJ9/XTpTm3P2YEGd+3Oa5/DOhXgji4?=
 =?us-ascii?Q?yrjvGhWr8bykCWXAXOkP3P0KiGjcs0k/bs2kYVwUgsH9EQ4QgpuY+4LnrkUu?=
 =?us-ascii?Q?smWhlHyke5ZVuYrzRnUgzIMOkJO8cf8ZPzisD46hm4Hmkf3CmIff1IKSfQ94?=
 =?us-ascii?Q?FudVjA1GW3wrDgPTrwFZF9S9gJi1rV7n2z/bHiHMAYMo0PYd82N9mrxHndAb?=
 =?us-ascii?Q?ht1YV+PW1zpisqZt15cV4MjB8T5aBRD3+xMY3W4M/d3Q6ewS7++JzLp6GQH+?=
 =?us-ascii?Q?zFiZRTTf9RHrunsIAOb6iRLBMnCuWxwfTM0p2PU/eN4Vv5oDjKIB8ht1aDI+?=
 =?us-ascii?Q?Y+b+XOXWd1rijDorUJie80o5pb8uyaEZcbvNeqwl4WlNCEeHofr8wmMx0G3j?=
 =?us-ascii?Q?xLTb4aOjVg2lRcN54C0pt+/XP3sXwFWA48PSThikZ0cwtCtoPKhQYi68DWZ+?=
 =?us-ascii?Q?ix304T1bQSW42BRKD/9IGHG5DHRqzlucFyOiNf4YcARbSp6GCFwXU50omn0j?=
 =?us-ascii?Q?JkwkgXBG9A8itJBsfvJ880lI/4j6bmQcXOqry1VAudjYou9X/IbjWpbI5DEf?=
 =?us-ascii?Q?CLuLqeb8QUYy/+g6+qSWVZwjAAzMh0DOOuHgsWaQKnR951StxSwGyMA1tV87?=
 =?us-ascii?Q?e6/Cm/Su4dncbBR13h1Iqn9H3lEG6Y2b0kF9QMK5?=
X-MS-Exchange-CrossTenant-Network-Message-Id: 14f25aee-440c-47ff-20dc-08db719459d9
X-MS-Exchange-CrossTenant-AuthSource: SA1PR11MB6733.namprd11.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 20 Jun 2023 13:43:38.3250
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 46c98d88-e344-4ed4-8496-4ed7712e255d
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: 9P0vehPMRW0y2eT+TzuN9/IvKqzgVqGh+EzG+RDQFjbo9Lm4aX2VrUhf3acOFyapnHotAzu/c3JZRsAzvt5f1w==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: BN9PR11MB5452
X-OriginatorOrg: intel.com
X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,
        DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED,
        SPF_HELO_NONE,SPF_NONE,T_SCC_BODY_TEXT_LINE,URIBL_BLOCKED
        autolearn=ham autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

Jiasheng Jiang wrote:
> Add check for the return value of kstrdup() and return the error
> if it fails in order to avoid NULL pointer dereference.
> Moreover, use kfree() in the later error handling in order to avoid
> memory leak.
> 
> Fixes: 49bddc73d15c ("libnvdimm/of_pmem: Provide a unique name for bus provider")
> Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
> ---
>  drivers/nvdimm/of_pmem.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/nvdimm/of_pmem.c b/drivers/nvdimm/of_pmem.c
> index 10dbdcdfb9ce..fe6edb7e6631 100644
> --- a/drivers/nvdimm/of_pmem.c
> +++ b/drivers/nvdimm/of_pmem.c
> @@ -31,11 +31,17 @@ static int of_pmem_region_probe(struct platform_device *pdev)
>  		return -ENOMEM;
>  
>  	priv->bus_desc.provider_name = kstrdup(pdev->name, GFP_KERNEL);
> +	if (!priv->bus_desc.provider_name) {
> +		kfree(priv);
> +		return -ENOMEM;
> +	}
> +
>  	priv->bus_desc.module = THIS_MODULE;
>  	priv->bus_desc.of_node = np;
>  
>  	priv->bus = bus = nvdimm_bus_register(&pdev->dev, &priv->bus_desc);
>  	if (!bus) {
> +		kfree(priv->bus_desc.provider_name);

Nice catch!

However, this free needs to happen in of_pmem_region_remove() as well.

Ira

>  		kfree(priv);
>  		return -ENODEV;
>  	}
> -- 
> 2.25.1
>