media: dib0700: fix rc endpoint lookup

commit f52981019ad8d6718de79b425a574c6bddf81f7c upstream.

Make sure to use the current alternate setting when verifying the
interface descriptors to avoid submitting an URB to an invalid endpoint.

Failing to do so could cause the driver to misbehave or trigger a WARN()
in usb_submit_urb() that kernels with panic_on_warn set would choke on.

Fixes: c4018fa2e4c0 ("[media] dib0700: fix RC support on Hauppauge Nova-TD")
Cc: stable <stable@vger.kernel.org>     # 3.16
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/media/usb/dvb-usb/dib0700_core.c b/drivers/media/usb/dvb-usb/dib0700_core.c
index d1b4b729e814ffdff2a01c7243d57983146e3c5d..49dd3ea2947dc2b599020f499ce906ad5de0a362 100644 (file)
--- a/drivers/media/usb/dvb-usb/dib0700_core.c
+++ b/drivers/media/usb/dvb-usb/dib0700_core.c
@@ -783,7 +783,7 @@ 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)
+       if (intf->cur_altsetting->desc.bNumEndpoints < rc_ep + 1)
                return -ENODEV;
 
        purb = usb_alloc_urb(0, GFP_KERNEL);
@@ -805,7 +805,7 @@ int dib0700_rc_setup(struct dvb_usb_device *d, struct usb_interface *intf)
         * Some devices like the Hauppauge NovaTD model 52009 use an interrupt
         * endpoint, while others use a bulk one.
         */
-       e = &intf->altsetting[0].endpoint[rc_ep].desc;
+       e = &intf->cur_altsetting->endpoint[rc_ep].desc;
        if (usb_endpoint_dir_in(e)) {
                if (usb_endpoint_xfer_bulk(e)) {
                        pipe = usb_rcvbulkpipe(d->udev, rc_ep);