From: Dan Carpenter <dan.carpenter@linaro.org>
To: Li Zhijian <lizhijian@fujitsu.com>
Cc: dave@stgolabs.net, jonathan.cameron@huawei.com,
dave.jiang@intel.com, alison.schofield@intel.com,
vishal.l.verma@intel.com, ira.weiny@intel.com,
dan.j.williams@intel.com, linux-cxl@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 13:17:03 +0300 [thread overview]
Message-ID: <df5830dd-d822-4c11-9cce-3775dff0113b@moroto.mountain> (raw)
In-Reply-To: <20240429013154.368118-2-lizhijian@fujitsu.com>
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.
regards,
dan carpenter
next prev parent reply other threads:[~2024-04-29 10:17 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 [this message]
2024-04-29 10:26 ` Zhijian Li (Fujitsu)
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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