From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S267690AbUHYPPK (ORCPT ); Wed, 25 Aug 2004 11:15:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267827AbUHYPPK (ORCPT ); Wed, 25 Aug 2004 11:15:10 -0400 Received: from imladris.demon.co.uk ([193.237.130.41]:51977 "EHLO phoenix.infradead.org") by vger.kernel.org with ESMTP id S267690AbUHYPPG (ORCPT ); Wed, 25 Aug 2004 11:15:06 -0400 Date: Wed, 25 Aug 2004 16:15:04 +0100 From: Christoph Hellwig To: Linux kernel list Subject: Re: [Patch] TIOCCONS security Message-ID: <20040825161504.A8896@infradead.org> Mail-Followup-To: Christoph Hellwig , Linux kernel list References: <20040825151106.GA21687@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5.1i In-Reply-To: <20040825151106.GA21687@suse.de>; from od@suse.de on Wed, Aug 25, 2004 at 05:11:06PM +0200 X-SRS-Rewrite: SMTP reverse-path rewritten from by phoenix.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 25, 2004 at 05:11:06PM +0200, Olaf Dabrunz wrote: > Hi, > > the ioctl TIOCCONS allows any user to redirect console output to another > tty. This allows anyone to suppress messages to the console at will. > > AFAIK nowadays not many programs write to /dev/console, except for start > scripts and the kernel (printk() above console log level). > > Still, I believe that administrators and operators would not like any > user to be able to hijack messages that were written to the console. > > The only user of TIOCCONS that I am aware of is bootlogd/blogd, which > runs as root. Please comment if there are other users. Oh, common. Do your basic research - this has been rejected a few times and there have been better proposals. Just use goggle a little bit.