From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753267Ab1BDIkK (ORCPT ); Fri, 4 Feb 2011 03:40:10 -0500 Received: from brother.balabit.com ([195.70.62.219]:44541 "EHLO lists.balabit.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752996Ab1BDIkI (ORCPT ); Fri, 4 Feb 2011 03:40:08 -0500 Subject: Re: CAP_SYSLOG, 2.6.38 and user space From: Gergely Nagy To: Marc Koschewski Cc: david@lang.hm, "Serge E. Hallyn" , Linux Kernel Mailing List , James Morris In-Reply-To: <20110204080302.GA24941@marc.osknowledge.org> References: <1296733177.14846.26.camel@moria> <20110203153252.GA24153@mail.hallyn.com> <1296748401.14846.39.camel@moria> <20110203165132.GA28172@mail.hallyn.com> <20110204080302.GA24941@marc.osknowledge.org> Content-Type: text/plain; charset="UTF-8" Date: Fri, 04 Feb 2011 09:40:04 +0100 Message-ID: <1296808804.24742.6.camel@moria> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2011-02-04 at 09:03 +0100, Marc Koschewski wrote: > Moreover, this change really is 'hell' on _many_ machines. We had discussed a > thousands time to not break existing applications. So a) either make it optional in > the kernel so that userspace still works with CAP_SYS_ADMIN _and_ CAP_SYSLOG > while dropping a note that it should be fixed in userspace _and_ mark it as > deprecated as of mid 2012 or b) revert it. I think the sysctl method would be superior, because it places the migration time in the hands of the distributions/admins, and gives syslogds a way to adjust, and use either CAP_SYS_ADMIN or CAP_SYSLOG, based on the presence of the sysctl setting (as opposed to using either and just postponing the flag-day from 2.6.38 to mid 2012, where we'd have the same issues we have now: unupgraded userspace breaking). Having both CAP_SYS_ADMIN and CAP_SYSLOG at the same time, for the sole purpose of reading kernel log messages would kind of defeat the purpose of CAP_SYSLOG. Therefore, a solution that allows both at the same time doesn't look all that good to me. However, having it toggle-able does, and solves all my worries at least: defaulting to CAP_SYS_ADMIN maintains backwards compatibility, upgraded systems can switch to CAP_SYSLOG if and when the system is ready for that. All's well! -- |8]