From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752157Ab1BFBRt (ORCPT ); Sat, 5 Feb 2011 20:17:49 -0500 Received: from 184-106-158-135.static.cloud-ips.com ([184.106.158.135]:51280 "EHLO mail" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751747Ab1BFBRs (ORCPT ); Sat, 5 Feb 2011 20:17:48 -0500 Date: Sun, 6 Feb 2011 01:18:31 +0000 From: "Serge E. Hallyn" To: david@lang.hm Cc: "Serge E. Hallyn" , Gergely Nagy , James Morris , Linux Kernel Mailing List Subject: Re: CAP_SYSLOG, 2.6.38 and user space Message-ID: <20110206011831.GB15805@mail.hallyn.com> References: <1296733177.14846.26.camel@moria> <20110203153252.GA24153@mail.hallyn.com> <20110204160513.GB17396@mail.hallyn.com> <1296837186.24742.15.camel@moria> <20110204171502.GA24226@mail.hallyn.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Quoting david@lang.hm (david@lang.hm): > On Fri, 4 Feb 2011, Serge E. Hallyn wrote: > > >Quoting Gergely Nagy (algernon@balabit.hu): > >>On Fri, 2011-02-04 at 16:05 +0000, Serge E. Hallyn wrote: > >>>Quoting Serge E. Hallyn (serge@hallyn.com): > >>>>>From 2d7408541dd3a6e19a4265b028233789be6a40f4 Mon Sep 17 00:00:00 2001 > >>>>From: Serge Hallyn > >>>> > >>>>At 2.6.39 or 2.6.40, let's add a sysctl which defaults to 0. When > >>>>0, refuse if cap_sys_admin, if 1, then allow. This will allow > >>>>users to acknowledge (permanently, if they must, using /etc/sysctl.conf) > >>>>that they've seen the syslog message about cap_sys_admin being > >>>>deprecated for syslog. > >>>> > >>>>Signed-off-by: Serge Hallyn > >- goto warn; /* switch to return -EPERM after 2.6.39 */ > >+ !capable(CAP_SYSLOG)) { > >+ /* remove after 2.6.39 */ > >+ if (capable(CAP_SYS_ADMIN)) > >+ WARN_ONCE(1, "Attempt to access syslog with CAP_SYS_ADMIN " > >+ "but no CAP_SYSLOG (deprecated).\n"); > >+ else > >+ return -EPERM; > >+ } > > } > > why does this need to be removed after 2.6.39? > > whenever you go to remove it you will break userspace, what's the > benifit of breaking userspace? > > I can understand that it's better to have a syslog daemon with > CAP_SYSLOG instead of CAP_SYS_ADMIN, but does "it would be better to > have userspace changed" really translate into "it's so important to > have userspace changed that we need to break any userspace that > hasn't changed"? > > I really don't think so. I think I agree with you. If someone wants to grant one of the other CAP_SYS_ADMIN powers without CAP_SYSLOG, then they can break that into yet another, i.e. CAP_IPCSET. Makes sense. thanks, -serge