From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757268Ab2ARTl0 (ORCPT ); Wed, 18 Jan 2012 14:41:26 -0500 Received: from nikam.ms.mff.cuni.cz ([195.113.20.16]:45075 "EHLO nikam.ms.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756327Ab2ARTlY (ORCPT ); Wed, 18 Jan 2012 14:41:24 -0500 Date: Wed, 18 Jan 2012 20:41:22 +0100 From: Martin Mares To: Andi Kleen Cc: Linus Torvalds , Indan Zupancic , Jamie Lokier , Andrew Lutomirski , Oleg Nesterov , Will Drewry , linux-kernel@vger.kernel.org, keescook@chromium.org, john.johansen@canonical.com, serge.hallyn@canonical.com, coreyb@linux.vnet.ibm.com, pmoore@redhat.com, eparis@redhat.com, djm@mindrot.org, segoon@openwall.com, rostedt@goodmis.org, jmorris@namei.org, scarybeasts@gmail.com, avi@redhat.com, penberg@cs.helsinki.fi, viro@zeniv.linux.org.uk, mingo@elte.hu, akpm@linux-foundation.org, khilman@ti.com, borislav.petkov@amd.com, amwang@redhat.com, ak@linux.intel.com, eric.dumazet@gmail.com, gregkh@suse.de, dhowells@redhat.com, daniel.lezcano@free.fr, linux-fsdevel@vger.kernel.org, linux-security-module@vger.kernel.org, olofj@chromium.org, mhalcrow@google.com, dlaor@redhat.com, Roland McGrath Subject: Re: Compat 32-bit syscall entry from 64-bit task!? Message-ID: References: <49017bd7edab7010cd9ac767e39d99e4.squirrel@webmail.greenhost.nl> <20120118015013.GR11715@one.firstfloor.org> <20120118020453.GL7180@jl-vm1.vm.bytemark.co.uk> <20120118022217.GS11715@one.firstfloor.org> <20120118193602.GV11715@one.firstfloor.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120118193602.GV11715@one.firstfloor.org> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello! > The real fix is really to use a LSM for custom jails. Trying to make > ptrace secure is trying to make a sieve wather tight by plugging the individual > holes one by one. It's simply not suitable for this. As long as the set of syscalls which are permitted is trivial, it should be secure and much easier than writing a custom LSM. Regardless, having working strace would be nice. Have a nice fortnight -- Martin `MJ' Mares http://mj.ucw.cz/ Faculty of Math and Physics, Charles University, Prague, Czech Rep., Earth "Never send to know for whom the bell tolls: it tolls for thee." -- John Donne From mboxrd@z Thu Jan 1 00:00:00 1970 From: Martin Mares Subject: Re: Compat 32-bit syscall entry from 64-bit task!? Date: Wed, 18 Jan 2012 20:41:22 +0100 Message-ID: References: <49017bd7edab7010cd9ac767e39d99e4.squirrel@webmail.greenhost.nl> <20120118015013.GR11715@one.firstfloor.org> <20120118020453.GL7180@jl-vm1.vm.bytemark.co.uk> <20120118022217.GS11715@one.firstfloor.org> <20120118193602.GV11715@one.firstfloor.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Linus Torvalds , Indan Zupancic , Jamie Lokier , Andrew Lutomirski , Oleg Nesterov , Will Drewry , linux-kernel@vger.kernel.org, keescook@chromium.org, john.johansen@canonical.com, serge.hallyn@canonical.com, coreyb@linux.vnet.ibm.com, pmoore@redhat.com, eparis@redhat.com, djm@mindrot.org, segoon@openwall.com, rostedt@goodmis.org, jmorris@namei.org, scarybeasts@gmail.com, avi@redhat.com, penberg@cs.helsinki.fi, viro@zeniv.linux.org.uk, mingo@elte.hu, akpm@linux-foundation.org, khilman@ti.com, borislav.petkov@amd.com, amwang@redhat.com, ak@linux.intel.com, eric.dumazet@gmail.com, gregkh@suse.de, dhowells@redhat.com, daniel.lezcano@free.fr, linux-fsdevel@vger.kernel.org, linux-security-module@vger.kernel.org, olofj@chromium.org, mhalcrow@google.com, dlaor@ To: Andi Kleen Return-path: Content-Disposition: inline In-Reply-To: <20120118193602.GV11715@one.firstfloor.org> Sender: linux-security-module-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org Hello! > The real fix is really to use a LSM for custom jails. Trying to make > ptrace secure is trying to make a sieve wather tight by plugging the individual > holes one by one. It's simply not suitable for this. As long as the set of syscalls which are permitted is trivial, it should be secure and much easier than writing a custom LSM. Regardless, having working strace would be nice. Have a nice fortnight -- Martin `MJ' Mares http://mj.ucw.cz/ Faculty of Math and Physics, Charles University, Prague, Czech Rep., Earth "Never send to know for whom the bell tolls: it tolls for thee." -- John Donne