Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755902Ab1BIVeZ (ORCPT ); Wed, 9 Feb 2011 16:34:25 -0500 Received: from mail.lang.hm ([64.81.33.126]:59853 "EHLO bifrost.lang.hm" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755802Ab1BIVeY (ORCPT ); Wed, 9 Feb 2011 16:34:24 -0500 Date: Wed, 9 Feb 2011 13:34:18 -0800 (PST) From: david@lang.hm X-X-Sender: dlang@asgard.lang.hm To: Gergely Nagy cc: "Serge E. Hallyn" , James Morris , Linux Kernel Mailing List Subject: Re: CAP_SYSLOG, 2.6.38 and user space In-Reply-To: <1297286934.13055.57.camel@luthien.mhp> Message-ID: 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> <20110206011831.GB15805@mail.hallyn.com> <20110209212329.GA24777@mail.hallyn.com> <1297286934.13055.57.camel@luthien.mhp> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1957 Lines: 45 On Wed, 9 Feb 2011, Gergely Nagy wrote: > On Wed, 2011-02-09 at 21:23 +0000, Serge E. Hallyn wrote: >> So if that's how we're leaning, then the following patch is much more >> concise. I'll send this to Linus and any appropriate -stable tomorrow >> if noone objects. >> >> From 5166e114d6a7c508addbadd763322089eb0b02f5 Mon Sep 17 00:00:00 2001 >> From: Serge Hallyn >> Date: Thu, 3 Feb 2011 09:26:15 -0600 >> Subject: [PATCH 1/1] cap_syslog: don't refuse cap_sys_admin for now (v2) >> >> It'd be nice to do that later, but it's not strictly necessary, >> and it'll be hard to do without breaking somebody's userspace. >> >> Signed-off-by: Serge Hallyn >> --- >> kernel/printk.c | 14 ++++---------- >> 1 files changed, 4 insertions(+), 10 deletions(-) > > Personally, I'd prefer the sysctl idea in the long run, because > userspace can easily and automatically adapt to the running kernel then. > Ie, this patch is fine for 2.6.38, but later on, a sysctl could be > introduced, that when set (but defaulting to unset, as to not break > userspace), would make CAP_SYS_ADMIN return -EPERM. That way, syslogds > could look at the setting, and act accordingly. This would mean that old > userspace wouldn't break, and upgraded userspace could work on both old > and new kernels, depending on the setting. Distros or admins could then > enable the sysctl once they made sure that all neccessary applications > have been upgraded. what is your justification for ever having CAP_SYS_ADMIN return -EPERM? what's the value in blocking this. David Lang > But this works too, for now. My immediate concern is making sure 2.6.38 > doesn't break capability-using syslogds. > > -- 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/