Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: Linux 5.1-rc2
To:     Kees Cook <keescook@chromium.org>
Cc:     James Morris <jmorris@namei.org>,
        Randy Dunlap <rdunlap@infradead.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Linux List Kernel Mailing <linux-kernel@vger.kernel.org>,
        linux-security-module <linux-security-module@vger.kernel.org>,
        Jakub Kicinski <jakub.kicinski@netronome.com>
References: <CAHk-=wgg_PRWs3a6u2gnFLQjhxOJcrFkqqWVnLw60eQAwD-DNw@mail.gmail.com>
 <2d4f3bfa-22c7-a18c-3902-fe1b6ac401f7@infradead.org>
 <alpine.LRH.2.21.1903260607500.13529@namei.org>
 <8811b2e4-28e1-2f01-024b-fb7d0196483f@i-love.sakura.ne.jp>
 <CAGXu5jJZ1H1RFMFBxPsoBW+T17ya+50-d7-31Gr9ciRgpCOaDA@mail.gmail.com>
 <98289cd2-095a-f0cd-e405-887ecbba0030@i-love.sakura.ne.jp>
 <CAGXu5jKWECKxksJWPpCkBKG+wB26DhYK=nYBpuuoS+Pv9AsNwQ@mail.gmail.com>
From:   Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Message-ID: <e1f6f5a6-9fce-2e95-4593-79f1e836bac5@i-love.sakura.ne.jp>
Date:   Thu, 28 Mar 2019 06:05:42 +0900
User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:60.0) Gecko/20100101
 Thunderbird/60.6.0
MIME-Version: 1.0
In-Reply-To: <CAGXu5jKWECKxksJWPpCkBKG+wB26DhYK=nYBpuuoS+Pv9AsNwQ@mail.gmail.com>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On 2019/03/28 5:45, Kees Cook wrote:
> On Wed, Mar 27, 2019 at 1:30 PM Tetsuo Handa
> <penguin-kernel@i-love.sakura.ne.jp> wrote:
>>
>> On 2019/03/28 4:16, Kees Cook wrote:
>>> The part I don't understand is what you've said about TOMOYO being
>>> primary and not wanting the others stackable? That kind of goes
>>> against the point, but I'm happy to do that if you want it that way.
>>
>> Automatically enabling multiple legacy major LSMs might result in a confusion like
>> Jakub encountered.
> 
> The confusion wasn't multiple enabled: it was a change of what was
> enabled (due to ignoring the old config). (My very first suggested
> patch fixed this...)

Someone else might get confused when TOMOYO is automatically enabled
despite they did not specify TOMOYO in lsm= or security= or CONFIG_LSM.

> 
>> For a few releases from 5.1 (about one year or so?), since
>> CONFIG_DEFAULT_SECURITY_* will be ignored after CONFIG_LSM is once defined in
>> their kernel configs, I guess that it is better not to enable TOMOYO automatically
>> until most people complete migrating from CONFIG_DEFAULT_SECURITY_* to CONFIG_LSM
>> and get used to use lsm= kernel command line option rather than security= kernel
>> command line option.
> 
> It sounds like you want TOMOYO to stay an exclusive LSM? Should we
> revert a5e2fe7ede12 ("TOMOYO: Update LSM flags to no longer be
> exclusive") instead? (I'm against this idea, but defer to you. I think
> it should stay stackable since the goal is to entirely remove the
> concept of exclusive LSMs.)

I never want to revert a5e2fe7ede12. For transition period, I just don't
want to automatically enable TOMOYO when people did not specify TOMOYO.

> 
> I don't see problems for an exclusive LSM user (AA, SELinux, Smack)
> also initializing TOMOYO, though. It should be a no-op. Is there some
> situation where this is not true?

There should be no problem except some TOMOYO messages are printed.