From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:45506 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932463AbdEKOWM (ORCPT ); Thu, 11 May 2017 10:22:12 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Johan Hovold Subject: [PATCH 4.9 057/103] USB: serial: keyspan_pda: fix receive sanity checks Date: Thu, 11 May 2017 16:12:26 +0200 Message-Id: <20170511141215.261629928@linuxfoundation.org> In-Reply-To: <20170511141210.778405364@linuxfoundation.org> References: <20170511141210.778405364@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Johan Hovold commit c528fcb116e61afc379a2e0a0f70906b937f1e2c upstream. Make sure to check for short transfers before parsing the receive buffer to avoid acting on stale data. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reviewed-by: Greg Kroah-Hartman Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/keyspan_pda.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) --- a/drivers/usb/serial/keyspan_pda.c +++ b/drivers/usb/serial/keyspan_pda.c @@ -139,6 +139,7 @@ static void keyspan_pda_rx_interrupt(str { struct usb_serial_port *port = urb->context; unsigned char *data = urb->transfer_buffer; + unsigned int len = urb->actual_length; int retval; int status = urb->status; struct keyspan_pda_private *priv; @@ -159,18 +160,26 @@ static void keyspan_pda_rx_interrupt(str goto exit; } + if (len < 1) { + dev_warn(&port->dev, "short message received\n"); + goto exit; + } + /* see if the message is data or a status interrupt */ switch (data[0]) { case 0: /* rest of message is rx data */ - if (urb->actual_length) { - tty_insert_flip_string(&port->port, data + 1, - urb->actual_length - 1); - tty_flip_buffer_push(&port->port); - } + if (len < 2) + break; + tty_insert_flip_string(&port->port, data + 1, len - 1); + tty_flip_buffer_push(&port->port); break; case 1: /* status interrupt */ + if (len < 3) { + dev_warn(&port->dev, "short interrupt message received\n"); + break; + } dev_dbg(&port->dev, "rx int, d1=%d, d2=%d\n", data[1], data[2]); switch (data[1]) { case 1: /* modemline change */