Re: [PATCH] [media] cx231xx-cards: fix NULL-deref on missing association descriptor

[Andrey Konovalov]

On Thu, Sep 21, 2017 at 10:40 AM, Johan Hovold  wrote:
> 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  # 2.6.30
> Cc: Sri Deevi 
> Reported-by: Andrey Konovalov 
> Signed-off-by: Johan Hovold 

Tested-by: Andrey Konovalov 

Thanks!

> ---
>  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 e0daa9b6c2a0..9b742d569fb5 100644
> --- a/drivers/media/usb/cx231xx/cx231xx-cards.c
> +++ b/drivers/media/usb/cx231xx/cx231xx-cards.c
> @@ -1684,7 +1684,7 @@ 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) {
> dev_err(d, "Not found matching IAD interface\n");
> retval = -ENODEV;
> goto err_if;
> --
> 2.14.1
>

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

[Johan Hovold]

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  # 2.6.30
Cc: Sri Deevi 
Reported-by: Andrey Konovalov 
Signed-off-by: Johan Hovold 
---
 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 e0daa9b6c2a0..9b742d569fb5 100644
--- a/drivers/media/usb/cx231xx/cx231xx-cards.c
+++ b/drivers/media/usb/cx231xx/cx231xx-cards.c
@@ -1684,7 +1684,7 @@ 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) {
dev_err(d, "Not found matching IAD interface\n");
retval = -ENODEV;
goto err_if;
-- 
2.14.1