USB: rndis: Fix for handling garbled messages

A message can be forged to crash the stack; here we make sure we don't
completely break the system if this occurs

Signed-off-by: Michel Pollet <michel.pollet@bp.renesas.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/gadget/function/rndis.c

@@ -851,6 +851,9 @@ int rndis_msg_parser(struct rndis_params *params, u8 *buf)
 		 */
 		pr_warn("%s: unknown RNDIS message 0x%08X len %d\n",
 			__func__, MsgType, MsgLength);
+		/* Garbled message can be huge, so limit what we display */
+		if (MsgLength > 16)
+			MsgLength = 16;
 		print_hex_dump_bytes(__func__, DUMP_PREFIX_OFFSET,
 				     buf, MsgLength);
 		break;