From 38db3716a5f8f022ae38f7431913e6b479015b74 Mon Sep 17 00:00:00 2001
From: Michael Grzeschik <m.grzeschik@pengutronix.de>
Date: Sun, 17 Oct 2021 23:50:14 +0200
Subject: [PATCH] usb: gadget: uvc: test if ep->desc is valid on ep_queue
Git-commit: 38db3716a5f8f022ae38f7431913e6b479015b74
References: git-fixes
Patch-mainline: v5.16-rc1

The reason that the ep_queue has failed could be a disabled endpoint.
In that case it is not guaranteed that the ep->desc is still valid.
This patch adds a check for NULL.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Link: https://lore.kernel.org/r/20211017215017.18392-4-m.grzeschik@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
 drivers/usb/gadget/function/uvc_video.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c
index f3e97a4fc030..4222192fa624 100644
--- a/drivers/usb/gadget/function/uvc_video.c
+++ b/drivers/usb/gadget/function/uvc_video.c
@@ -199,9 +199,12 @@ static int uvcg_video_ep_queue(struct uvc_video *video, struct usb_request *req)
 		uvcg_err(&video->uvc->func, "Failed to queue request (%d).\n",
 			 ret);
 
-		/* Isochronous endpoints can't be halted. */
-		if (usb_endpoint_xfer_bulk(video->ep->desc))
-			usb_ep_set_halt(video->ep);
+		/* If the endpoint is disabled the descriptor may be NULL. */
+		if (video->ep->desc) {
+			/* Isochronous endpoints can't be halted. */
+			if (usb_endpoint_xfer_bulk(video->ep->desc))
+				usb_ep_set_halt(video->ep);
+		}
 	}
 
 	return ret;
-- 
2.39.0