usb: gadget: renesas_usb3: validate endpoint index in standard request handlers

The GET_STATUS and SET/CLEAR_FEATURE handlers extract the endpoint
number from the host-supplied wIndex without any sort of validation.
Fix this up by validating the number of endpoints actually match up with
the number the device has before attempting to dereference a pointer
based on this math.

This is just like what was done in commit ee0d382 ("usb: gadget:
aspeed_udc: validate endpoint index for ast udc") for the aspeed driver.

Fixes: 746bfe6 ("usb: gadget: renesas_usb3: add support for Renesas USB3.0 peripheral controller")
Cc: stable <stable@kernel.org>
Assisted-by: gregkh_clanker_t1000
Link: https://patch.msgid.link/2026040647-sincerity-untidy-b104@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: gregkh

drivers/usb/gadget/udc/renesas_usb3.c

@@ -1669,6 +1669,10 @@ static bool usb3_std_req_get_status(struct renesas_usb3 *usb3,
 		break;
 	case USB_RECIP_ENDPOINT:
 		num = le16_to_cpu(ctrl->wIndex) & USB_ENDPOINT_NUMBER_MASK;
+		if (num >= usb3->num_usb3_eps) {
+			stall = true;
+			break;
+		}
 		usb3_ep = usb3_get_ep(usb3, num);
 		if (usb3_ep->halt)
 			status |= 1 << USB_ENDPOINT_HALT;
@@ -1781,7 +1785,8 @@ static bool usb3_std_req_feature_endpoint(struct renesas_usb3 *usb3,
 	struct renesas_usb3_ep *usb3_ep;
 	struct renesas_usb3_request *usb3_req;
 
-	if (le16_to_cpu(ctrl->wValue) != USB_ENDPOINT_HALT)
+	if ((le16_to_cpu(ctrl->wValue) != USB_ENDPOINT_HALT) ||
+	    (num >= usb3->num_usb3_eps))
 		return true;	/* stall */
 
 	usb3_ep = usb3_get_ep(usb3, num);