From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754082Ab2ALPnl (ORCPT ); Thu, 12 Jan 2012 10:43:41 -0500 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.125]:45369 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753706Ab2ALPnk (ORCPT ); Thu, 12 Jan 2012 10:43:40 -0500 X-Authority-Analysis: v=2.0 cv=SqgSGYy0 c=1 sm=0 a=ZycB6UtQUfgMyuk2+PxD7w==:17 a=CN4PQ-MNGcoA:10 a=5SG0PmZfjMsA:10 a=Q9fys5e9bTEA:10 a=6-N4bbpydDtNlQQiLSgA:9 a=PUjeQqilurYA:10 a=ZycB6UtQUfgMyuk2+PxD7w==:117 X-Cloudmark-Score: 0 X-Originating-IP: 74.67.80.29 Message-ID: <1326383015.7642.77.camel@gandalf.stny.rr.com> Subject: Re: [RFC,PATCH 1/2] seccomp_filters: system call filtering using BPF From: Steven Rostedt To: Will Drewry Cc: 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, torvalds@linux-foundation.org, segoon@openwall.com, jmorris@namei.org, scarybeasts@gmail.com, avi@redhat.com, penberg@cs.helsinki.fi, viro@zeniv.linux.org.uk, luto@mit.edu, mingo@elte.hu, akpm@linux-foundation.org, khilman@ti.com, borislav.petkov@amd.com, amwang@redhat.com, oleg@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 Date: Thu, 12 Jan 2012 10:43:35 -0500 In-Reply-To: <1326302710-9427-2-git-send-email-wad@chromium.org> References: <1326302710-9427-1-git-send-email-wad@chromium.org> <1326302710-9427-2-git-send-email-wad@chromium.org> Content-Type: text/plain; charset="ISO-8859-15" X-Mailer: Evolution 3.2.2-1 Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2012-01-11 at 11:25 -0600, Will Drewry wrote: > Filter programs may _only_ cross the execve(2) barrier if last filter > program was attached by a task with CAP_SYS_ADMIN capabilities in its > user namespace. Once a task-local filter program is attached from a > process without privileges, execve will fail. This ensures that only > privileged parent task can affect its privileged children (e.g., setuid > binary). This means that a non privileged user can not run another program with limited features? How would a process exec another program and filter it? I would assume that the filter would need to be attached first and then the execv() would be performed. But after the filter is attached, the execv is prevented? Maybe I don't understand this correctly. -- Steve