From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753333AbaIXIlU (ORCPT ); Wed, 24 Sep 2014 04:41:20 -0400 Received: from filter1.ibarracuda.nl ([83.247.7.10]:53302 "EHLO filter1.ibarracuda.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750793AbaIXIlP (ORCPT ); Wed, 24 Sep 2014 04:41:15 -0400 X-ASG-Debug-ID: 1411548073-0759e70b7300bc0002-xx1T2L X-Barracuda-Envelope-From: Frans.Klaver@xsens.com X-Barracuda-AUTH-User: xsenscom X-Barracuda-Apparent-Source-IP: 87.249.116.215 Date: Wed, 24 Sep 2014 10:41:11 +0200 From: Frans Klaver To: Greg Kroah-Hartman CC: Jiri Slaby , , , Subject: Re: [PATCH 1/2] tty: omap-serial: fix division by zero Message-ID: <20140924084111.GA22872@ci00147.xsens-tech.local> X-ASG-Orig-Subj: Re: [PATCH 1/2] tty: omap-serial: fix division by zero References: <1411545322-22940-1-git-send-email-frans.klaver@xsens.com> <1411545322-22940-2-git-send-email-frans.klaver@xsens.com> <20140924080852.GA28215@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Disposition: inline In-Reply-To: <20140924080852.GA28215@kroah.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-Originating-IP: [172.16.11.160] X-Barracuda-Connect: rev-215.116.249.87.virtu.nl[87.249.116.215] X-Barracuda-Start-Time: 1411548073 X-Barracuda-Encrypted: AES128-SHA X-Barracuda-URL: http://filter1.ibarracuda.nl:8000/cgi-mod/mark.cgi X-Barracuda-BRTS-Status: 1 X-Barracuda-Spam-Score: 0.00 X-Barracuda-Spam-Status: No, SCORE=0.00 using per-user scores of TAG_LEVEL=1000.0 QUARANTINE_LEVEL=1000.0 KILL_LEVEL=5.0 tests= X-Barracuda-Spam-Report: Code version 3.2, rules version 3.2.3.9818 Rule breakdown below pts rule name description ---- ---------------------- -------------------------------------------------- Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Sep 24, 2014 at 01:08:52AM -0700, Greg Kroah-Hartman wrote: > On Wed, Sep 24, 2014 at 09:55:21AM +0200, Frans Klaver wrote: > > If the chosen baud rate is large enough (e.g. 3.5 megabaud), the > > calculated n values in serial_omap_is_baud_mode16() may become 0. This > > causes a division by zero when calculating the difference between > > calculated and desired baud rates. To prevent this, cap the n13 and n16 > > values on 1. > > > > Division by zero in kernel. > > [] (unwind_backtrace) from [] (show_stack+0x10/0x14) > > [] (show_stack) from [] (Ldiv0+0x8/0x10) > > [] (Ldiv0) from [] (serial_omap_baud_is_mode16+0x4c/0x68) > > [] (serial_omap_baud_is_mode16) from [] (serial_omap_set_termios+0x90/0x8d8) > > [] (serial_omap_set_termios) from [] (uart_change_speed+0xa4/0xa8) > > [] (uart_change_speed) from [] (uart_set_termios+0xa0/0x1fc) > > [] (uart_set_termios) from [] (tty_set_termios+0x248/0x2c0) > > [] (tty_set_termios) from [] (set_termios+0x248/0x29c) > > [] (set_termios) from [] (tty_mode_ioctl+0x1c8/0x4e8) > > [] (tty_mode_ioctl) from [] (tty_ioctl+0xa94/0xb18) > > [] (tty_ioctl) from [] (do_vfs_ioctl+0x4a0/0x560) > > [] (do_vfs_ioctl) from [] (SyS_ioctl+0x4c/0x74) > > [] (SyS_ioctl) from [] (ret_fast_syscall+0x0/0x30) > > > > Signed-off-by: Frans Klaver > > --- > > drivers/tty/serial/omap-serial.c | 12 ++++++++++-- > > 1 file changed, 10 insertions(+), 2 deletions(-) > > Should this go to the stable kernel trees as well? It's been there for a while. Introduced in 5fe2123647c1508 "OMAP/serial: Support 1Mbaud and similar baudrates that require Mode16 instead of Mode13" (v3.9). It's probably a good idea to do so. stable@... needs a cc? Frans