From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751379AbdFAPnI (ORCPT ); Thu, 1 Jun 2017 11:43:08 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:60873 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751221AbdFAPnF (ORCPT ); Thu, 1 Jun 2017 11:43:05 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Johan Hovold" , "Greg Kroah-Hartman" Date: Thu, 01 Jun 2017 16:40:55 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 034/101] USB: serial: keyspan_pda: fix receive sanity checks In-Reply-To: X-SA-Exim-Connect-IP: 82.70.136.246 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.89-rc1 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 [bwh: Backported to 3.2: - Adjust context - Keep the check for !tty in the data case] Signed-off-by: Ben Hutchings --- 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 @@ -212,6 +212,7 @@ static void keyspan_pda_rx_interrupt(str struct usb_serial_port *port = urb->context; struct tty_struct *tty; unsigned char *data = urb->transfer_buffer; + unsigned int len = urb->actual_length; int retval; int status = urb->status; struct keyspan_pda_private *priv; @@ -234,20 +235,28 @@ 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: tty = tty_port_tty_get(&port->port); /* rest of message is rx data */ - if (tty && urb->actual_length) { - tty_insert_flip_string(tty, data + 1, - urb->actual_length - 1); - tty_flip_buffer_push(tty); - } + if (!tty || len < 2) + break; + tty_insert_flip_string(tty, data + 1, len - 1); + tty_flip_buffer_push(tty); tty_kref_put(tty); break; case 1: /* status interrupt */ + if (len < 3) { + dev_warn(&port->dev, "short interrupt message received\n"); + break; + } dbg(" rx int, d1=%d, d2=%d", data[1], data[2]); switch (data[1]) { case 1: /* modemline change */