From f52981019ad8d6718de79b425a574c6bddf81f7c Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan@kernel.org>
Date: Fri, 3 Jan 2020 17:35:12 +0100
Subject: [PATCH] media: dib0700: fix rc endpoint lookup
Git-commit: f52981019ad8d6718de79b425a574c6bddf81f7c
Patch-mainline: v5.7-rc1
References: bsc#1051510

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>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/media/usb/dvb-usb/dib0700_core.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/media/usb/dvb-usb/dib0700_core.c b/drivers/media/usb/dvb-usb/dib0700_core.c
index e53c58ab6488..ef62dd6c5ae4 100644
--- a/drivers/media/usb/dvb-usb/dib0700_core.c
+++ b/drivers/media/usb/dvb-usb/dib0700_core.c
@@ -818,7 +818,7 @@ 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);
@@ -838,7 +838,7 @@ 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);
-- 
2.16.4