[PATCH 3.16 033/134] [media] dib0700: fix NULL-deref at probe

Ben Hutchings
2017-08-18T13:15:43Z

From: Johan Hovold <johan@kernel.org>

commit d5823511c0f8719a39e72ede1bce65411ac653b7 upstream.

Make sure to check the number of endpoints to avoid dereferencing a
NULL-pointer should a malicious device lack endpoints.

Fixes: c4018fa2e4c0 ("[media] dib0700: fix RC support on Hauppauge
Nova-TD")

Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/media/usb/dvb-usb/dib0700_core.c | 3 +++
1 file changed, 3 insertions(+)

--- a/drivers/media/usb/dvb-usb/dib0700_core.c
+++ b/drivers/media/usb/dvb-usb/dib0700_core.c
@@ -769,6 +769,9 @@ int dib0700_rc_setup(struct dvb_usb_devi

/* Starting in firmware 1.20, the RC info is provided on a bulk pipe */

+ if (intf->altsetting[0].desc.bNumEndpoints < rc_ep + 1)
+ return -ENODEV;
+
purb = usb_alloc_urb(0, GFP_KERNEL);
if (purb == NULL) {
err("rc usb alloc urb failed");