[PATCH 4.9 20/29] USB: gadget: validate endpoint index for xilinx udc

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

From: Szymon Heidrich <szymon.heidrich@gmail.com>

commit 7f14c7227f342d9932f9b918893c8814f86d2a0d upstream.

Assure that host may not manipulate the index to point
past endpoint array.

Signed-off-by: Szymon Heidrich <szymon.heidrich@gmail.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/usb/gadget/udc/udc-xilinx.c |    6 ++++++
 1 file changed, 6 insertions(+)

--- a/drivers/usb/gadget/udc/udc-xilinx.c
+++ b/drivers/usb/gadget/udc/udc-xilinx.c
@@ -1620,6 +1620,8 @@ static void xudc_getstatus(struct xusb_u
 		break;
 	case USB_RECIP_ENDPOINT:
 		epnum = udc->setup.wIndex & USB_ENDPOINT_NUMBER_MASK;
+		if (epnum >= XUSB_MAX_ENDPOINTS)
+			goto stall;
 		target_ep = &udc->ep[epnum];
 		epcfgreg = udc->read_fn(udc->addr + target_ep->offset);
 		halt = epcfgreg & XUSB_EP_CFG_STALL_MASK;
@@ -1687,6 +1689,10 @@ static void xudc_set_clear_feature(struc
 	case USB_RECIP_ENDPOINT:
 		if (!udc->setup.wValue) {
 			endpoint = udc->setup.wIndex & USB_ENDPOINT_NUMBER_MASK;
+			if (endpoint >= XUSB_MAX_ENDPOINTS) {
+				xudc_ep0_stall(udc);
+				return;
+			}
 			target_ep = &udc->ep[endpoint];
 			outinbit = udc->setup.wIndex & USB_ENDPOINT_DIR_MASK;
 			outinbit = outinbit >> 7;