dib0700: fix NULL-deref at probe

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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/media/usb/dvb-usb/dib0700_core.c b/drivers/media/usb/dvb-usb/dib0700_core.c
index 47ce9d5de4c6..563f690cd978 100644
--- a/drivers/media/usb/dvb-usb/dib0700_core.c
+++ b/drivers/media/usb/dvb-usb/dib0700_core.c
@@ -812,6 +812,9 @@ int dib0700_rc_setup(struct dvb_usb_device *d, struct usb_interface *intf)
 
         /* 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)
                 return -ENOMEM;