usb: core: config: fix validation of wMaxPacketValue entries

The checks performed by commit aed9d65a ("USB: validate
wMaxPacketValue entries in endpoint descriptors") require that initial
value of the maxp variable contains both maximum packet size bits
(10..0) and multiple-transactions bits (12..11). However, the existing
code assings only the maximum packet size bits. This patch assigns all
bits of wMaxPacketSize to the variable.

Fixes: aed9d65a ("USB: validate wMaxPacketValue entries in endpoint descriptors")
Cc: stable <stable@vger.kernel.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Pavel Hofman <pavel.hofman@ivitera.com>
Link: https://lore.kernel.org/r/20211210085219.16796-1-pavel.hofman@ivitera.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/core/config.c

@@ -406,7 +406,7 @@ static int usb_parse_endpoint(struct device *ddev, int cfgno,
 	 * the USB-2 spec requires such endpoints to have wMaxPacketSize = 0
 	 * (see the end of section 5.6.3), so don't warn about them.
 	 */
-	maxp = usb_endpoint_maxp(&endpoint->desc);
+	maxp = le16_to_cpu(endpoint->desc.wMaxPacketSize);
 	if (maxp == 0 && !(usb_endpoint_xfer_isoc(d) && asnum == 0)) {
 		dev_warn(ddev, "config %d interface %d altsetting %d endpoint 0x%X has invalid wMaxPacketSize 0\n",
 		    cfgno, inum, asnum, d->bEndpointAddress);