[PATCH 4.4 63/96] [media] cx231xx-cards: fix NULL-deref on missing association descriptor

Greg Kroah-Hartman
2017-11-28T10:30:24Z

From: Johan Hovold <johan@kernel.org>

commit 6c3b047fa2d2286d5e438bcb470c7b1a49f415f6 upstream.

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")
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Tested-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/media/usb/cx231xx/cx231xx-cards.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/media/usb/cx231xx/cx231xx-cards.c
+++ b/drivers/media/usb/cx231xx/cx231xx-cards.c
@@ -1672,7 +1672,7 @@ static int cx231xx_usb_probe(struct usb_
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;