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Subject: Re: [PATCH 16/18] LSM: Allow arbitrary LSM ordering
To:     Kees Cook <keescook@chromium.org>,
        =?UTF-8?Q?Micka=c3=abl_Sala=c3=bcn?= <mic@digikod.net>
Cc:     John Johansen <john.johansen@canonical.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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From:   Casey Schaufler <casey@schaufler-ca.com>
Message-ID: <3a90fe88-d74a-2c2c-c949-cabcaad2e1da@schaufler-ca.com>
Date:   Mon, 17 Sep 2018 16:30:54 -0700
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On 9/17/2018 4:20 PM, Kees Cook wrote:
> On Mon, Sep 17, 2018 at 4:10 PM, Mickaël Salaün <mic@digikod.net> 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.

What harm would it cause for Landlock to get called before SELinux?
I certainly see why it seems like it ought to get called after, but
would it really make a difference?

> Good point! It will be easy to add LSM_ORDER_LAST, though, given the
> machinery introduced in this series.
>
> -Kees
>