From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:55952 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752321AbdBIM6g (ORCPT ); Thu, 9 Feb 2017 07:58:36 -0500 Subject: patch "USB: serial: ftdi_sio: fix modem-status error handling" added to usb-testing To: johan@kernel.org, gregkh@linuxfoundation.org, stable@vger.kernel.org From: Date: Thu, 09 Feb 2017 13:57:56 +0100 Message-ID: <1486645076212104@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled USB: serial: ftdi_sio: fix modem-status error handling to my usb git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git in the usb-testing branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will be merged to the usb-next branch sometime soon, after it passes testing, and the merge window is open. If you have any questions about this process, please let me know. >>From 427c3a95e3e29e65f59d99aaf320d7506f3eed57 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Thu, 12 Jan 2017 14:56:11 +0100 Subject: USB: serial: ftdi_sio: fix modem-status error handling Make sure to detect short responses when fetching the modem status in order to avoid parsing uninitialised buffer data and having bits of it leak to user space. Note that we still allow for short 1-byte responses. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable Reviewed-by: Greg Kroah-Hartman Signed-off-by: Johan Hovold --- drivers/usb/serial/ftdi_sio.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c index 23d14b98ae2a..6dee20fc7e45 100644 --- a/drivers/usb/serial/ftdi_sio.c +++ b/drivers/usb/serial/ftdi_sio.c @@ -2428,8 +2428,12 @@ static int ftdi_get_modem_status(struct usb_serial_port *port, FTDI_SIO_GET_MODEM_STATUS_REQUEST_TYPE, 0, priv->interface, buf, len, WDR_TIMEOUT); - if (ret < 0) { + + /* NOTE: We allow short responses and handle that below. */ + if (ret < 1) { dev_err(&port->dev, "failed to get modem status: %d\n", ret); + if (ret >= 0) + ret = -EIO; ret = usb_translate_errors(ret); goto out; } -- 2.11.1