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From:   Kees Cook <keescook@chromium.org>
Date:   Mon, 17 Sep 2018 16:28:24 -0700
Message-ID: <CAGXu5j+haqMgKxkH12M3O358oBR-jU0uWTZSrCrm462mtgf26A@mail.gmail.com>
Subject: Re: [PATCH 16/18] LSM: Allow arbitrary LSM ordering
To:     John Johansen <john.johansen@canonical.com>
Cc:     =?UTF-8?B?TWlja2HDq2wgU2FsYcO8bg==?= <mic@digikod.net>,
        Casey Schaufler <casey@schaufler-ca.com>,
        James Morris <jmorris@namei.org>,
        Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>,
        Paul Moore <paul@paul-moore.com>,
        Stephen Smalley <sds@tycho.nsa.gov>,
        "Schaufler, Casey" <casey.schaufler@intel.com>,
        LSM <linux-security-module@vger.kernel.org>,
        LKLM <linux-kernel@vger.kernel.org>
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On Mon, Sep 17, 2018 at 4:26 PM, John Johansen
<john.johansen@canonical.com> wrote:
> On 09/17/2018 04:20 PM, Kees Cook wrote:
>> On Mon, Sep 17, 2018 at 4:10 PM, Micka=C3=ABl Sala=C3=BCn <mic@digikod.n=
et> wrote:
>>> Landlock, because it target unprivileged users, should only be called
>>> after all other major (access-control) LSMs. The admin or distro must
>>> not be able to change that order in any way. This constraint doesn't
>>> apply to current LSMs, though.
>>
>> Good point! It will be easy to add LSM_ORDER_LAST, though, given the
>> machinery introduced in this series.
>>
>
> And when we have two LSMs that want to use that?

We'll cross that bridge when we come to it, but perhaps "last
exclusive"? (lsm.enable/disable to choose)

-Kees

--=20
Kees Cook
Pixel Security