Re: [media] hdpvr: Fix an error handling path in hdpvr_probe()

[Guenter Roeck <linux@roeck-us.net>]

On Fri, Sep 22, 2017 at 06:37:06PM +0530, Arvind Yadav wrote:
> Here, hdpvr_register_videodev() is responsible for setup and
> register a video device. Also defining and initializing a worker.
> hdpvr_register_videodev() is calling by hdpvr_probe at last.
> So No need to flash any work here.
> Unregister v4l2, free buffers and memory. If hdpvr_probe() will fail.
> 
> Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
> Reported-by: Andrey Konovalov <andreyknvl@google.com>
> Tested-by: Andrey Konovalov <andreyknvl@google.com>

It looks like this patch was never applied upstream. It fixes
CVE-2017-16644 [1].

Did it get lost, or is there some reason for not applying it ?

Thanks,
Guenter

---
[1] https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-16644

> ---
>  drivers/media/usb/hdpvr/hdpvr-core.c | 26 +++++++++++++++-----------
>  1 file changed, 15 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/media/usb/hdpvr/hdpvr-core.c b/drivers/media/usb/hdpvr/hdpvr-core.c
> index dbe29c6..1e8cbaf 100644
> --- a/drivers/media/usb/hdpvr/hdpvr-core.c
> +++ b/drivers/media/usb/hdpvr/hdpvr-core.c
> @@ -292,7 +292,7 @@ static int hdpvr_probe(struct usb_interface *interface,
>  	/* register v4l2_device early so it can be used for printks */
>  	if (v4l2_device_register(&interface->dev, &dev->v4l2_dev)) {
>  		dev_err(&interface->dev, "v4l2_device_register failed\n");
> -		goto error;
> +		goto error_free_dev;
>  	}
>  
>  	mutex_init(&dev->io_mutex);
> @@ -301,7 +301,7 @@ static int hdpvr_probe(struct usb_interface *interface,
>  	dev->usbc_buf = kmalloc(64, GFP_KERNEL);
>  	if (!dev->usbc_buf) {
>  		v4l2_err(&dev->v4l2_dev, "Out of memory\n");
> -		goto error;
> +		goto error_v4l2_unregister;
>  	}
>  
>  	init_waitqueue_head(&dev->wait_buffer);
> @@ -339,13 +339,13 @@ static int hdpvr_probe(struct usb_interface *interface,
>  	}
>  	if (!dev->bulk_in_endpointAddr) {
>  		v4l2_err(&dev->v4l2_dev, "Could not find bulk-in endpoint\n");
> -		goto error;
> +		goto error_put_usb;
>  	}
>  
>  	/* init the device */
>  	if (hdpvr_device_init(dev)) {
>  		v4l2_err(&dev->v4l2_dev, "device init failed\n");
> -		goto error;
> +		goto error_put_usb;
>  	}
>  
>  	mutex_lock(&dev->io_mutex);
> @@ -353,7 +353,7 @@ static int hdpvr_probe(struct usb_interface *interface,
>  		mutex_unlock(&dev->io_mutex);
>  		v4l2_err(&dev->v4l2_dev,
>  			 "allocating transfer buffers failed\n");
> -		goto error;
> +		goto error_put_usb;
>  	}
>  	mutex_unlock(&dev->io_mutex);
>  
> @@ -361,7 +361,7 @@ static int hdpvr_probe(struct usb_interface *interface,
>  	retval = hdpvr_register_i2c_adapter(dev);
>  	if (retval < 0) {
>  		v4l2_err(&dev->v4l2_dev, "i2c adapter register failed\n");
> -		goto error;
> +		goto error_free_buffers;
>  	}
>  
>  	client = hdpvr_register_ir_rx_i2c(dev);
> @@ -394,13 +394,17 @@ static int hdpvr_probe(struct usb_interface *interface,
>  reg_fail:
>  #if IS_ENABLED(CONFIG_I2C)
>  	i2c_del_adapter(&dev->i2c_adapter);
> +error_free_buffers:
>  #endif
> +	hdpvr_free_buffers(dev);
> +error_put_usb:
> +	usb_put_dev(dev->udev);
> +	kfree(dev->usbc_buf);
> +error_v4l2_unregister:
> +	v4l2_device_unregister(&dev->v4l2_dev);
> +error_free_dev:
> +	kfree(dev);
>  error:
> -	if (dev) {
> -		flush_work(&dev->worker);
> -		/* this frees allocated memory */
> -		hdpvr_delete(dev);
> -	}
>  	return retval;
>  }
>