From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1033089AbdEWUop (ORCPT ); Tue, 23 May 2017 16:44:45 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:50420 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161343AbdEWUjA (ORCPT ); Tue, 23 May 2017 16:39:00 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Johan Hovold Subject: [PATCH 4.4 064/103] USB: serial: io_ti: fix div-by-zero in set_termios Date: Tue, 23 May 2017 22:09:30 +0200 Message-Id: <20170523200901.985563122@linuxfoundation.org> X-Mailer: git-send-email 2.13.0 In-Reply-To: <20170523200856.903752266@linuxfoundation.org> References: <20170523200856.903752266@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Johan Hovold commit 6aeb75e6adfaed16e58780309613a578fe1ee90b upstream. Fix a division-by-zero in set_termios when debugging is enabled and a high-enough speed has been requested so that the divisor value becomes zero. Instead of just fixing the offending debug statement, cap the baud rate at the base as a zero divisor value also appears to crash the firmware. 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/io_ti.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/drivers/usb/serial/io_ti.c +++ b/drivers/usb/serial/io_ti.c @@ -2349,8 +2349,11 @@ static void change_port_settings(struct if (!baud) { /* pick a default, any default... */ baud = 9600; - } else + } else { + /* Avoid a zero divisor. */ + baud = min(baud, 461550); tty_encode_baud_rate(tty, baud, baud); + } edge_port->baud_rate = baud; config->wBaudRate = (__u16)((461550L + baud/2) / baud);