Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751295AbVLCVoE (ORCPT ); Sat, 3 Dec 2005 16:44:04 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751299AbVLCVoE (ORCPT ); Sat, 3 Dec 2005 16:44:04 -0500 Received: from hera.cwi.nl ([192.16.191.8]:57319 "EHLO hera.cwi.nl") by vger.kernel.org with ESMTP id S1751295AbVLCVoD (ORCPT ); Sat, 3 Dec 2005 16:44:03 -0500 Date: Sat, 3 Dec 2005 22:43:49 +0100 From: Andries Brouwer To: Bodo Eggert <7eggert@gmx.de> Cc: Andries Brouwer , linux-kernel@vger.kernel.org, akpm@osdl.org, horms@verge.net.au Subject: Re: security / kbd Message-ID: <20051203214349.GB26620@apps.cwi.nl> References: <5f6Fp-1ZB-11@gated-at.bofh.it> <20051203013455.GB24760@apps.cwi.nl> <20051203023946.GC24760@apps.cwi.nl> <20051203144659.GA2091@apps.cwi.nl> <20051203181140.GA25534@apps.cwi.nl> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1165 Lines: 29 On Sat, Dec 03, 2005 at 07:48:19PM +0100, Bodo Eggert wrote: > > You argue "you can't keep an exploit open" - but as far as I can see > > there is no problem that needs solving in kernel space. > > For example - today login does a single vhangup() for the login tty. > > In case that is a VC it could do a vhangup() for all VCs. > > That looks like a better solution. > > I tried this, but > 1) vhangup doesn't seem to close file descriptors, so it won't help > against the exploit Yes, it does. The permission test was current->signal->tty == tty and even if the file descriptor may still be open, after a vhangup the loadkeys call fails. > 2) even if it did, the behaviour you described would kill all console > sessions at once when you terminate one, which is very undesirable Your definition of desirable is not mine. In all cases it is bad to put policy in the kernel. Policy belongs in user space. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/