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From: "Zhijian Li (Fujitsu)" <lizhijian@fujitsu.com>
To: Dan Carpenter <dan.carpenter@linaro.org>
Cc: "dave@stgolabs.net" <dave@stgolabs.net>,
	"jonathan.cameron@huawei.com" <jonathan.cameron@huawei.com>,
	"dave.jiang@intel.com" <dave.jiang@intel.com>,
	"alison.schofield@intel.com" <alison.schofield@intel.com>,
	"vishal.l.verma@intel.com" <vishal.l.verma@intel.com>,
	"ira.weiny@intel.com" <ira.weiny@intel.com>,
	"dan.j.williams@intel.com" <dan.j.williams@intel.com>,
	"linux-cxl@vger.kernel.org" <linux-cxl@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 2/2] cxl/region: Fix missing put_device(region_dev)
Date: Mon, 29 Apr 2024 10:26:47 +0000	[thread overview]
Message-ID: <cd20f733-3523-490c-8bc1-73b7300f18b8@fujitsu.com> (raw)
In-Reply-To: <df5830dd-d822-4c11-9cce-3775dff0113b@moroto.mountain>



On 29/04/2024 18:17, Dan Carpenter wrote:
> On Mon, Apr 29, 2024 at 09:31:54AM +0800, Li Zhijian wrote:
>>>          mutex_lock(&cxlrd->range_lock);
>>>          region_dev = device_find_child(&cxlrd->cxlsd.cxld.dev, hpa,
>>>                                         match_region_by_range);
>>>          if (!region_dev)
>>>                  cxlr = construct_region(cxlrd, cxled);
>>>          else
>>>                  cxlr = to_cxl_region(region_dev);
>>>          mutex_unlock(&cxlrd->range_lock);
>>>
>>>          rc = PTR_ERR_OR_ZERO(cxlr);
>>>          if (rc)
>>>                  goto out;
>>>
>>>          if (!region_dev)
>>>                  region_dev = &cxlr->dev;
>>
>> When to_cxl_region(region_dev) fails,
>    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> to_cxl_region() will return NULL if "region_dev" is not a region device.
> 
>    2215  static struct cxl_region *to_cxl_region(struct device *dev)
>    2216  {
>    2217          if (dev_WARN_ONCE(dev, dev->type != &cxl_region_type,
>    2218                            "not a cxl_region device\n"))
>    2219                  return NULL;
>    2220
>    2221          return container_of(dev, struct cxl_region, dev);
>    2222  }
> 
> It won't fail.
> 
> If it does fail, we're already in bad shape and it's not worth worrying
> about resource leaks at that point.
> 

Sounds good to me,

Thanks
Zhijian


> regards,
> dan carpenter
> 
> 

  reply	other threads:[~2024-04-29 10:27 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-29  1:31 [PATCH 1/2] cxl/region: Fix potential invalid pointer dereference Li Zhijian
2024-04-29  1:31 ` [PATCH 2/2] cxl/region: Fix missing put_device(region_dev) Li Zhijian
2024-04-29  1:51   ` Zhijian Li (Fujitsu)
2024-04-29  8:00   ` Markus Elfring
2024-04-29  8:26     ` Zhijian Li (Fujitsu)
2024-04-29 10:00       ` Dan Carpenter
2024-04-29 10:11         ` Zhijian Li (Fujitsu)
2024-04-29  8:35   ` Zhijian Li (Fujitsu)
2024-04-29 10:17   ` Dan Carpenter
2024-04-29 10:26     ` Zhijian Li (Fujitsu) [this message]
2024-04-29 10:32       ` Dan Carpenter
2024-04-29 16:14   ` Ira Weiny
2024-04-29  7:50 ` [PATCH 1/2] cxl/region: Fix potential invalid pointer dereference Markus Elfring
2024-04-29  8:43   ` Zhijian Li (Fujitsu)
2024-04-29  8:55     ` [1/2] " Markus Elfring
2024-04-29 10:10 ` [PATCH 1/2] " Dan Carpenter
2024-04-29 10:25   ` Zhijian Li (Fujitsu)
2024-04-29 10:30     ` Dan Carpenter
2024-04-29 16:17   ` Ira Weiny
2024-04-29 16:05 ` Ira Weiny

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