Re: [PATCH] dvb-usb: Add memory free on error path in dw2102_probe()

[Enrico Mioso <mrkiko.rs@gmail.com>]

For me it's fine.

Reviewed-By: Enrico Mioso <mrkiko.rs@gmail.com>

On Thu, 10 Aug 2017, Anton Vasilyev wrote:

> Date: Thu, 10 Aug 2017 17:27:44
> From: Anton Vasilyev <vasilyev@ispras.ru>
> To: Mauro Carvalho Chehab <mchehab@kernel.org>
> Cc: Anton Vasilyev <vasilyev@ispras.ru>, Jonathan McDowell <noodles@earth.li>,
>     Alyssa Milburn <amilburn@zall.org>, Enrico Mioso <mrkiko.rs@gmail.com>,
>     linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
>     ldv-project@linuxtesting.org
> Subject: [PATCH] dvb-usb: Add memory free on error path in dw2102_probe()
> 
> If dw2102_probe() fails on dvb_usb_device_init(), then memleak occurs.
>
> The patch adds deallocation to the error path.
>
> Found by Linux Driver Verification project (linuxtesting.org).
>
> Signed-off-by: Anton Vasilyev <vasilyev@ispras.ru>
> ---
> drivers/media/usb/dvb-usb/dw2102.c | 39 +++++++++++++++++++++-----------------
> 1 file changed, 22 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/media/usb/dvb-usb/dw2102.c b/drivers/media/usb/dvb-usb/dw2102.c
> index 6e654e5..0d63693 100644
> --- a/drivers/media/usb/dvb-usb/dw2102.c
> +++ b/drivers/media/usb/dvb-usb/dw2102.c
> @@ -2332,10 +2332,12 @@ static struct dvb_usb_device_properties tt_s2_4600_properties = {
> static int dw2102_probe(struct usb_interface *intf,
> 		const struct usb_device_id *id)
> {
> +	int retval = -ENOMEM;
> 	p1100 = kmemdup(&s6x0_properties,
> 			sizeof(struct dvb_usb_device_properties), GFP_KERNEL);
> 	if (!p1100)
> -		return -ENOMEM;
> +		goto err0;
> +
> 	/* copy default structure */
> 	/* fill only different fields */
> 	p1100->firmware = P1100_FIRMWARE;
> @@ -2346,10 +2348,9 @@ static int dw2102_probe(struct usb_interface *intf,
>
> 	s660 = kmemdup(&s6x0_properties,
> 		       sizeof(struct dvb_usb_device_properties), GFP_KERNEL);
> -	if (!s660) {
> -		kfree(p1100);
> -		return -ENOMEM;
> -	}
> +	if (!s660)
> +		goto err1;
> +
> 	s660->firmware = S660_FIRMWARE;
> 	s660->num_device_descs = 3;
> 	s660->devices[0] = d660;
> @@ -2359,11 +2360,9 @@ static int dw2102_probe(struct usb_interface *intf,
>
> 	p7500 = kmemdup(&s6x0_properties,
> 			sizeof(struct dvb_usb_device_properties), GFP_KERNEL);
> -	if (!p7500) {
> -		kfree(p1100);
> -		kfree(s660);
> -		return -ENOMEM;
> -	}
> +	if (!p7500)
> +		goto err2;
> +
> 	p7500->firmware = P7500_FIRMWARE;
> 	p7500->devices[0] = d7500;
> 	p7500->rc.core.rc_query = prof_rc_query;
> @@ -2373,12 +2372,9 @@ static int dw2102_probe(struct usb_interface *intf,
>
> 	s421 = kmemdup(&su3000_properties,
> 		       sizeof(struct dvb_usb_device_properties), GFP_KERNEL);
> -	if (!s421) {
> -		kfree(p1100);
> -		kfree(s660);
> -		kfree(p7500);
> -		return -ENOMEM;
> -	}
> +	if (!s421)
> +		goto err3;
> +
> 	s421->num_device_descs = 2;
> 	s421->devices[0] = d421;
> 	s421->devices[1] = d632;
> @@ -2408,7 +2404,16 @@ static int dw2102_probe(struct usb_interface *intf,
> 			 THIS_MODULE, NULL, adapter_nr))
> 		return 0;
>
> -	return -ENODEV;
> +	retval = -ENODEV;
> +	kfree(s421);
> +err3:
> +	kfree(p7500);
> +err2:
> +	kfree(s660);
> +err1:
> +	kfree(p1100);
> +err0:
> +	return retval;
> }
>
> static void dw2102_disconnect(struct usb_interface *intf)
> -- 
> 2.7.4
>
>