Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:6 as permitted sender) client-ip=2620:137:e000::3:6;
Message-ID: <caf9a9e6-dea5-9dd7-846d-30d445b8ed2b@intel.com>
Date:   Tue, 26 Sep 2023 11:52:17 -0700
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Betterbird/102.13.0
Subject: Re: [PATCH v1 1/2] ACPI: NFIT: Fix memory leak, and local use of
 devm_*()
To:     Michal Wilczynski <michal.wilczynski@intel.com>,
        <linux-acpi@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <nvdimm@lists.linux.dev>
CC:     <rafael.j.wysocki@intel.com>, <andriy.shevchenko@intel.com>,
        <lenb@kernel.org>, <dan.j.williams@intel.com>,
        <vishal.l.verma@intel.com>, <ira.weiny@intel.com>,
        Andy Shevchenko <andy.shevchenko@gmail.com>
References: <20230926184520.2239723-1-michal.wilczynski@intel.com>
 <20230926184520.2239723-2-michal.wilczynski@intel.com>
Content-Language: en-US
From:   Dave Jiang <dave.jiang@intel.com>
In-Reply-To: <20230926184520.2239723-2-michal.wilczynski@intel.com>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?UDJZQnRJdXg5S2V3bm1FYUtVMGdOWXF0ZU51elN2RE45OXVXdTVSaHlYcDJU?=
 =?utf-8?B?WlR5U29wZGRNTDBnU2I5Yk04SlJFQnZnekZUREFjRUk0V1FmZEZHY3hhaXdQ?=
 =?utf-8?B?MUs2cDR6Ty9MenZMUVFHZ0h4QmRoc3lPSmkrOUpxOGhpYTdOcE9Wa01JVHZU?=
 =?utf-8?B?K01VSDFVcTluMDBpMElnbE1nU2JUcFdwcENKK0FBSEhXaHZWOEs1OUhncXlO?=
 =?utf-8?B?USs1aUJtY3ZxQXFvSkcrN096L2FhNHNiMEU5M1V2S09pOXMxbFk4ZC9TNk04?=
 =?utf-8?B?SFdKdXQrSVpSWStXaVRrSjRvdUVGdXB2YUVGcUJWTTgyeEpLTkdIa1lpaEd3?=
 =?utf-8?B?YTFseXhrbnlhb2dYaFh0dmRYU2RMdnlET25XbXFxOEZBREpULzBsbWdON1NP?=
 =?utf-8?B?UTZtTzFZd2c0YXdaRTExRVB0TjQ5NkdjUStOK2J6NEJWbnpzcThXMG5zVkN2?=
 =?utf-8?B?YTJWS04zZHFDb2JRYXNmNFR3cGtPeUpZQVpOemRYTEJkeWtQT0N1S2xxd2J3?=
 =?utf-8?B?anZzbW8rbzlCK0RLbjJvOGlORlB5MnphNnhpR2J2TCswRFZjVDdYTGoxaVlr?=
 =?utf-8?B?WmxnSmJsZXlxVmRPR243MklXNFBjVFdvQzk3RVp3MTB3REkrQzhXQW9NbSta?=
 =?utf-8?B?ZnpuZzBPTGsvVjNRYWZKUE93RjAzU0lRZjRLWW5PdlBkTGdmOVZHd25Ga0tJ?=
 =?utf-8?B?c053c2pGcjZrRklPOGxEYjcwUTdhbm11bFpRbkFRc2NXUFd4eStWcmlKclpZ?=
 =?utf-8?B?RlJBZUVva2FlaGZ6cFJqVFpld0RUajhnS0VSbGNhSVBNTkxtcWxFQmkreTdr?=
 =?utf-8?B?eDNNdmtDcjZYa0Rmb2daZHNDcjNUZzFSN3FpSTdqaW1ZSE1yRGxTeVhmSkJt?=
 =?utf-8?B?cEdkdWVmaXZwL3A2YXI0WkFSRDdMcnlSbDZYZVltVXo0cEp4YkF3bUUvbFd1?=
 =?utf-8?B?NEh4Slh2a0lqemdILzhVYi9WVk1xRTRDZGpRMUZITTJOSUdwK20vbk9jWk9h?=
 =?utf-8?B?UzZYYUFPUXhNSmFBTGU3ZERqYnpSajY4VFV4a3lUdjBVaVVKZFB4UTNiNTdL?=
 =?utf-8?B?WXlleHozdmJPazdyMWt6N21rdndkd3pSZm50OXJ0aUdwWGRMYXJsMTRKZVFo?=
 =?utf-8?B?dmZyOExLMklrbXNMM2EzcHZ2OVV0OGl1ZC8zUGV3ancyZkk1SFA0aCtLOTNH?=
 =?utf-8?B?ZFJSbDZpZnJ1TzhrR280M2JtejNMTFhWa0VFWTl3ODVucU9keWdBOXl4Qk1z?=
 =?utf-8?B?VG1sUFV5WlZtb1dqRGJaL0Q3RTVudWc4TlRnOGJBc1JDaUxYWjZZbGUyYysv?=
 =?utf-8?B?VmZuMzdEelJQMXBxNENzTmU5dEdxSzVMNDlrVWFoRDNEZ09RcXgrbkF0ZG40?=
 =?utf-8?B?UDVRdDhVUEhHck0yQmZvdXB3UVF6b2RsQThMU3dlQmJKUUQrd3Y1OTU4QkVC?=
 =?utf-8?B?N2Q3bHJON2gxYUgyem1iWTcyUmdTYktCTkxaNExweHlFNnFWVFhiZEdadTZq?=
 =?utf-8?B?cXk4NGZjbGg2aFBWaXRRNUlhTlBRdzN0UlJoUHJPRHYrY1JmckVrS3ZZMVBq?=
 =?utf-8?B?MjgwMW02dVRsNndFTkxwd1hYdHhPODMvWVZTQlRxQXo3cTRPWW1sbDNoTXBj?=
 =?utf-8?B?eFVGbHBVOTJUVnJMWVFOdU5QdXVWcDNJNldZRTI1QWZkekoybHcwcWdUQ0NG?=
 =?utf-8?B?bkdNRzUvQU9rUkRUN0tZYWViNWxlbmVYRWNzRFJUOVg0VUhHVyszc1FZRzlS?=
 =?utf-8?B?Nng3cW0ycXBjczdDYTdoUjBvZ2pscG1ENUtpQ2owZnNWd1pDRDlyaW5IaXp0?=
 =?utf-8?B?cjgxK1ROR3A4YzI0UndjUUpHYW14M3c5Q0pmL1pmeDVwVnpORW1nSVpjTW0w?=
 =?utf-8?B?bUJWNTJTQzRENVpGbzlEOHJRTWhpRi9yeENWbk1zQ3NSV2tXWTE2SnlxWmlI?=
 =?utf-8?B?TEthMzN0L2JJazJKUTdLTlc1MHpnR0FzYnNETGtWNGJlRjIwR0hEMFh6Tk94?=
 =?utf-8?B?a01VelpYREcwTEVIQ2xoUFpSQktGZTlrM0ZONGR5Q2lkdEg5YU5TQXdsNlhC?=
 =?utf-8?B?Mm1TSURqMm1vM0VmUFBmT056UEFjRE9DdjlsaHBhb0tPOVZPeVZSZlJxVmZG?=
 =?utf-8?B?UVBReWZZeUZpOG9pS2QzbFhJdVZzY1dVdmxEWWRoREt5QXJ2ckJ3dGR1RXBq?=
 =?utf-8?B?M0E9PQ==?=
X-MS-Exchange-CrossTenant-Network-Message-Id: e182da62-b0f1-4573-64d3-08dbbec1b6af
X-MS-Exchange-CrossTenant-AuthSource: PH7PR11MB5984.namprd11.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 26 Sep 2023 18:52:20.7807
 (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: jNPkji7et47PvF4VLh+3POJohvyzdKi0FY6VIB3bAIQl2J15+vwn7sM70r2cJn3o5WYSKTJfAY5Tpwaz9w6k2g==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: CO1PR11MB5202
X-OriginatorOrg: intel.com
X-Spam-Status: No, score=-2.3 required=5.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED,
	DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,
	MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS
	autolearn=unavailable autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on pete.vger.email
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (pete.vger.email [0.0.0.0]); Tue, 26 Sep 2023 11:52:49 -0700 (PDT)


On 9/26/23 11:45, Michal Wilczynski wrote:
> devm_*() family of functions purpose is managing memory attached to a
> device. So in general it should only be used for allocations that should
> last for the whole lifecycle of the device. This is not the case for
> acpi_nfit_init_interleave_set(). There are two allocations that are only
> used locally in this function. What's more - if the function exits on
> error path memory is never freed. It's still attached to dev and would
> be freed on device detach, so this leak could be called a 'local leak'.
> 
> Fix this by switching from devm_kcalloc() to kcalloc(), and adding
> proper rollback.
> 
> Fixes: eaf961536e16 ("libnvdimm, nfit: add interleave-set state-tracking infrastructure")
> Reported-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> Signed-off-by: Michal Wilczynski <michal.wilczynski@intel.com>

Reviewed-by: Dave Jiang <dave.jiang@intel.com>
> ---
>  drivers/acpi/nfit/core.c | 23 +++++++++++++++--------
>  1 file changed, 15 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
> index f0e6738ae3c9..78f0f855c4de 100644
> --- a/drivers/acpi/nfit/core.c
> +++ b/drivers/acpi/nfit/core.c
> @@ -2262,6 +2262,7 @@ static int acpi_nfit_init_interleave_set(struct acpi_nfit_desc *acpi_desc,
>  	u16 nr = ndr_desc->num_mappings;
>  	struct nfit_set_info2 *info2;
>  	struct nfit_set_info *info;
> +	int err = 0;
>  	int i;
>  
>  	nd_set = devm_kzalloc(dev, sizeof(*nd_set), GFP_KERNEL);
> @@ -2269,13 +2270,15 @@ static int acpi_nfit_init_interleave_set(struct acpi_nfit_desc *acpi_desc,
>  		return -ENOMEM;
>  	import_guid(&nd_set->type_guid, spa->range_guid);
>  
> -	info = devm_kcalloc(dev, nr, sizeof(*info), GFP_KERNEL);
> +	info = kcalloc(nr, sizeof(*info), GFP_KERNEL);
>  	if (!info)
>  		return -ENOMEM;
>  
> -	info2 = devm_kcalloc(dev, nr, sizeof(*info2), GFP_KERNEL);
> -	if (!info2)
> -		return -ENOMEM;
> +	info2 = kcalloc(nr, sizeof(*info2), GFP_KERNEL);
> +	if (!info2) {
> +		err = -ENOMEM;
> +		goto free_info;
> +	}
>  
>  	for (i = 0; i < nr; i++) {
>  		struct nd_mapping_desc *mapping = &ndr_desc->mapping[i];
> @@ -2289,7 +2292,8 @@ static int acpi_nfit_init_interleave_set(struct acpi_nfit_desc *acpi_desc,
>  
>  		if (!memdev || !nfit_mem->dcr) {
>  			dev_err(dev, "%s: failed to find DCR\n", __func__);
> -			return -ENODEV;
> +			err = -ENODEV;
> +			goto free_info2;
>  		}
>  
>  		map->region_offset = memdev->region_offset;
> @@ -2337,10 +2341,13 @@ static int acpi_nfit_init_interleave_set(struct acpi_nfit_desc *acpi_desc,
>  	}
>  
>  	ndr_desc->nd_set = nd_set;
> -	devm_kfree(dev, info);
> -	devm_kfree(dev, info2);
>  
> -	return 0;
> +free_info2:
> +	kfree(info2);
> +free_info:
> +	kfree(info);
> +
> +	return err;
>  }
>  
>  static int ars_get_cap(struct acpi_nfit_desc *acpi_desc,