From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yw1-f67.google.com ([209.85.161.67]:46364 "EHLO mail-yw1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727252AbeIUIsr (ORCPT ); Fri, 21 Sep 2018 04:48:47 -0400 Received: by mail-yw1-f67.google.com with SMTP id j131-v6so4630279ywc.13 for ; Thu, 20 Sep 2018 20:02:05 -0700 (PDT) Received: from mail-yb1-f169.google.com (mail-yb1-f169.google.com. [209.85.219.169]) by smtp.gmail.com with ESMTPSA id t10-v6sm3899906ywg.74.2018.09.20.20.02.02 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 20 Sep 2018 20:02:02 -0700 (PDT) Received: by mail-yb1-f169.google.com with SMTP id y9-v6so4864640ybh.0 for ; Thu, 20 Sep 2018 20:02:02 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <74ecd4ec-491b-93d7-4e3f-46f92121130b@canonical.com> References: <20180920162338.21060-1-keescook@chromium.org> <20180920162338.21060-27-keescook@chromium.org> <7d2cc28b-aee5-ee91-9362-f92f8ca30adc@schaufler-ca.com> <6c899d9e-45aa-8159-c402-b3c4d1936112@canonical.com> <74ecd4ec-491b-93d7-4e3f-46f92121130b@canonical.com> From: Kees Cook Date: Thu, 20 Sep 2018 20:02:01 -0700 Message-ID: Subject: Re: [PATCH security-next v2 26/26] LSM: Add all exclusive LSMs to ordered initialization Content-Type: text/plain; charset="UTF-8" Sender: linux-arch-owner@vger.kernel.org List-ID: To: John Johansen Cc: Casey Schaufler , James Morris , Tetsuo Handa , Paul Moore , Stephen Smalley , "Schaufler, Casey" , LSM , Jonathan Corbet , "open list:DOCUMENTATION" , linux-arch , LKML Message-ID: <20180921030201.q2odkskWx6XovqTdNSyFXgLgo8zLhym3e3i5AvPoBbA@z> On Thu, Sep 20, 2018 at 7:14 PM, John Johansen wrote: > On 09/20/2018 07:05 PM, Kees Cook wrote: >> On Thu, Sep 20, 2018 at 6:39 PM, John Johansen >> wrote: >>> On 09/20/2018 06:10 PM, Casey Schaufler wrote: >>>> On 9/20/2018 5:45 PM, Kees Cook wrote: >>>>> On Thu, Sep 20, 2018 at 5:25 PM, Casey Schaufler wrote: >>>>>> On 9/20/2018 9:23 AM, Kees Cook wrote: >>>>>>> config LSM_ORDER >>>>>>> string "Default initialization order of builtin LSMs" >>>>>>> - default "yama,loadpin,integrity" >>>>>>> + default "yama,loadpin,integrity,selinux,smack,tomoyo,apparmor" >>>>>> If I want to compile all the major modules into my kernel and use >>>>>> AppArmor by default would I use >>>>>> >>>>>> default "yama,loadpin,integrity,apparmor,selinux,smack,tomoyo" >>>>>> >>>>>> or >>>>>> >>>>>> default "yama,loadpin,integrity,apparmor" >>>>> I was expecting the former, but the latter will have the same result. >>> >>> t find having the two be equivalent violates expectations. At least >>> when considering the end goal of full/extreme stacking, its trivially >>> the same with current major lsms being exclusive >> >> This mixes "enablement" with "ordering", though, and I think the past >> threads have shown this to be largely problematic. >> >> However, with CONFIG_LSM_ENABLED, we get the effect you're looking for, IIUC. > > no, I was just stating in a world where we have full stacking those two > are not equivalent, as I would assume the order of any lsm not listed > may end up being different. Right, the ordering would be defined first by runtime (lsm.order=) followed any missing LSMs then ordered by their order in CONFIG_LSM_ORDER=, followed by any still missing LSMs then ordered by their order at link-time (which *may* be Makefile order, but could change with LTO, etc). >>>>>> When we have "blob-sharing" how could I compile in tomoyo, >>>>>> but exclude it without a boot line option? >>>>> Ooh, yes, this series has no way to do that. Perhaps >>>>> CONFIG_LSM_DISABLE in the same form as CONFIG_LSM_ORDER? I would >>>>> totally remove LoadPin's CONFIG for this in favor it. >>>> >>>> I would generally prefer an optional CONFIG_LSM_ENABLE to >>>> CONFIG_LSM_DISABLE, but I understand the logic behind your >>>> approach. I would be looking for something like >>>> >>> +1 on the CONFIG_LSM_ENABLE ove DISABLE >>> >>>> CONFIG LSM_ENABLE >>>> string "Default set of enabled LSMs" >>>> default "" >>>> >>>> as opposed to >>>> >>>> CONFIG LSM_DISABLE >>>> string "Default set of disabled LSMs" >>>> default "" >>>> >>>> where an empty string is interpreted as "use 'em all" >>>> in either case. >> >> Yes, I like CONFIG_LSM_ENABLE if "empty" means "enable all". Should >> CONFIG_LSM_ENABLE replace all the other CONFIG-based LSM >> enabling/disabling? > > I don't particularly like "empty" being "enable all". With that > how would I disable all builtin lsms so that I just boot with > capability. > > An option of all or even * is more explicit and leaves the empty > set to mean disable everything Okay, that works. I prefer "all" FWIW. -Kees -- Kees Cook Pixel Security