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Date:   Fri, 14 Oct 2022 10:59:35 -0700
From:   Kees Cook <keescook@chromium.org>
To:     =?iso-8859-1?Q?Micka=EBl_Sala=FCn?= <mic@digikod.net>
Cc:     Mimi Zohar <zohar@linux.ibm.com>, Paul Moore <paul@paul-moore.com>,
        James Morris <jmorris@namei.org>,
        "Serge E. Hallyn" <serge@hallyn.com>,
        Dmitry Kasatkin <dmitry.kasatkin@gmail.com>,
        linux-security-module@vger.kernel.org,
        linux-integrity@vger.kernel.org, KP Singh <kpsingh@kernel.org>,
        Casey Schaufler <casey@schaufler-ca.com>,
        John Johansen <john.johansen@canonical.com>,
        linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: Re: [PATCH 1/9] integrity: Prepare for having "ima" and "evm"
 available in "integrity" LSM
Message-ID: <202210141050.A8DF7D10@keescook>
References: <20221013222702.never.990-kees@kernel.org>
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 <08a8b202-69b4-e154-28f5-337a898acf61@digikod.net>
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On Fri, Oct 14, 2022 at 04:40:01PM +0200, Micka?l Sala?n wrote:
> This is not backward compatible

Why? Nothing will be running LSM hooks until init finishes, at which
point the integrity inode cache will be allocated. And ima and evm don't
start up until lateinit.

>, but can easily be fixed thanks to
> DEFINE_LSM().order

That forces the LSM to be enabled, which may not be desired?

> Side node: I proposed an alternative to that but it was Nacked:
> https://lore.kernel.org/all/20210222150608.808146-1-mic@digikod.net/

Yeah, for the reasons pointed out -- that can't work. The point is to
not have The Default LSM. I do think Casey's NAK was rather prickly,
though. ;)

-- 
Kees Cook