ACK: [SRU Bionic/Focal/Impish] USB: gadget: validate endpoint index for xilinx udc

[Tim Gardner]

Acked-by: Tim Gardner <tim.gardner at canonical.com>

On 4/7/22 09:03, Thadeu Lima de Souza Cascardo wrote:
> From: Szymon Heidrich <szymon.heidrich at gmail.com>
> 
> Assure that host may not manipulate the index to point
> past endpoint array.
> 
> Signed-off-by: Szymon Heidrich <szymon.heidrich at gmail.com>
> Cc: stable <stable at kernel.org>
> Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
> (cherry picked from commit 7f14c7227f342d9932f9b918893c8814f86d2a0d)
> CVE-2022-27223
> Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo at canonical.com>
> ---
>   drivers/usb/gadget/udc/udc-xilinx.c | 6 ++++++
>   1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/usb/gadget/udc/udc-xilinx.c b/drivers/usb/gadget/udc/udc-xilinx.c
> index 72f2ea062d55..283e86ed1433 100644
> --- a/drivers/usb/gadget/udc/udc-xilinx.c
> +++ b/drivers/usb/gadget/udc/udc-xilinx.c
> @@ -1612,6 +1612,8 @@ static void xudc_getstatus(struct xusb_udc *udc)
>   		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;
> @@ -1679,6 +1681,10 @@ static void xudc_set_clear_feature(struct xusb_udc *udc)
>   	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;

-- 
-----------
Tim Gardner
Canonical, Inc