Re: [PATCH -next] Fix null pointer dereference in thermal_release()

[Daniel Lezcano]

On 15/10/2021 10:32, Yuanzheng Song wrote:
> If both dev_set_name() and device_register() failed, then
> null pointer dereference occurs in thermal_release() which
> will use strncmp() to compare the name.
> 
> So fix it by adding dev_set_name() return value check.
> 
> Signed-off-by: Yuanzheng Song <songyuanzheng@xxxxxxxxxx>

Applied, thanks

> ---
>  drivers/thermal/thermal_core.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
> index 9e243d9f929e..6904b97fd6ea 100644
> --- a/drivers/thermal/thermal_core.c
> +++ b/drivers/thermal/thermal_core.c
> @@ -904,6 +904,10 @@ __thermal_cooling_device_register(struct device_node *np,
>  		goto out_kfree_cdev;
>  	cdev->id = ret;
>  
> +	ret = dev_set_name(&cdev->device, "cooling_device%d", cdev->id);
> +	if (ret)
> +		goto out_ida_remove;
> +
>  	cdev->type = kstrdup(type ? type : "", GFP_KERNEL);
>  	if (!cdev->type) {
>  		ret = -ENOMEM;
> @@ -918,7 +922,6 @@ __thermal_cooling_device_register(struct device_node *np,
>  	cdev->device.class = &thermal_class;
>  	cdev->devdata = devdata;
>  	thermal_cooling_device_setup_sysfs(cdev);
> -	dev_set_name(&cdev->device, "cooling_device%d", cdev->id);
>  	ret = device_register(&cdev->device);
>  	if (ret)
>  		goto out_kfree_type;
> @@ -1229,6 +1232,10 @@ thermal_zone_device_register(const char *type, int trips, int mask,
>  	tz->id = id;
>  	strlcpy(tz->type, type, sizeof(tz->type));
>  
> +	result = dev_set_name(&tz->device, "thermal_zone%d", tz->id);
> +	if (result)
> +		goto remove_id;
> +
>  	if (!ops->critical)
>  		ops->critical = thermal_zone_device_critical;
>  
> @@ -1250,7 +1257,6 @@ thermal_zone_device_register(const char *type, int trips, int mask,
>  	/* A new thermal zone needs to be updated anyway. */
>  	atomic_set(&tz->need_update, 1);
>  
> -	dev_set_name(&tz->device, "thermal_zone%d", tz->id);
>  	result = device_register(&tz->device);
>  	if (result)
>  		goto release_device;
> 


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