ACK/cmnt: [PATCH] [media] cx231xx-cards: fix NULL-deref on missing association descriptor

[Kleber Souza]

On 07/20/18 16:23, Paolo Pisati wrote:
> From: Johan Hovold <johan at kernel.org>
> 
> Make sure to check that we actually have an Interface Association
> Descriptor before dereferencing it during probe to avoid dereferencing a
> NULL-pointer.
> 
> Fixes: e0d3bafd0258 ("V4L/DVB (10954): Add cx231xx USB driver")
> 
> Cc: stable <stable at vger.kernel.org>     # 2.6.30
> Reported-by: Andrey Konovalov <andreyknvl at google.com>
> Signed-off-by: Johan Hovold <johan at kernel.org>
> Tested-by: Andrey Konovalov <andreyknvl at google.com>
> Signed-off-by: Hans Verkuil <hans.verkuil at cisco.com>
> Signed-off-by: Mauro Carvalho Chehab <mchehab at osg.samsung.com>
> (cherry picked from commit 6c3b047fa2d2286d5e438bcb470c7b1a49f415f6)

If changes are made to to make it apply we should mark the patch as
"(backported from ...)".

> Signed-off-by: Paolo Pisati <paolo.pisati at canonical.com>

Acked-by: Kleber Sacilotto de Souza <kleber.souza at canonical.com>

> ---
>  drivers/media/usb/cx231xx/cx231xx-cards.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/media/usb/cx231xx/cx231xx-cards.c b/drivers/media/usb/cx231xx/cx231xx-cards.c
> index 528cce9..09d4fb6 100644
> --- a/drivers/media/usb/cx231xx/cx231xx-cards.c
> +++ b/drivers/media/usb/cx231xx/cx231xx-cards.c
> @@ -1224,7 +1224,7 @@ static int cx231xx_usb_probe(struct usb_interface *interface,
>  	nr = dev->devno;
>  
>  	assoc_desc = udev->actconfig->intf_assoc[0];
> -	if (assoc_desc->bFirstInterface != ifnum) {
> +	if (!assoc_desc || assoc_desc->bFirstInterface != ifnum) {
>  		cx231xx_err(DRIVER_NAME ": Not found "
>  			    "matching IAD interface\n");
>  		retval = -ENODEV;
>