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Date:   Thu, 24 Feb 2022 18:42:29 +0100
From:   Petr Vorel <pvorel@suse.cz>
To:     Casey Schaufler <casey@schaufler-ca.com>
Cc:     zohar@linux.ibm.com, dvyukov@google.com, ebiggers@kernel.org,
        jmorris@namei.org, keescook@chromium.org,
        linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-security-module@vger.kernel.org, serge@hallyn.com
Subject: Re: [PATCH 2/2] integrity: double check iint_cache was initialized
Message-ID: <YhfDhYQYZTU0clAf@pevik>
Reply-To: Petr Vorel <pvorel@suse.cz>
References: <20210322154207.6802-2-zohar@linux.ibm.com>
 <20220224142025.2587-1-pvorel@suse.cz>
 <418628ea-f524-05a1-8bfc-a688fa2d625d@schaufler-ca.com>
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Hi Casey,

> On 2/24/2022 6:20 AM, Petr Vorel wrote:
> > Hi Mimi, Tetsuo, Kees, all,

> > FYI this commit merged as 92063f3ca73a ("integrity: double check iint_cache was initialized")
> > is the reason for openSUSE distro installer going back from lsm= to deprecated
> > security= when filling default grub parameters because security=apparmor or
> > security=selinux does not break boot when used with ima_policy=tcb, unlike
> > using lsm.

> OK, color me confused. Integrity isn't an LSM. It doesn't
> call security_add_hooks().
Really: "Initially I also questioned making "integrity" an LSM.  Perhaps it's
time to reconsider." [1]

> > @Kees, @Mimi sure, people who use ima_policy=tcb will just remove lsm parameter
> > or add "integrity" to it but I wonder whether there could be "integrity"
> > automatic inclusion when using ima_policy=tcb. Although the point of lsm= (and
> > CONFIG_LSM) is to have *ordered* list of enabled LSMs and it wouldn't be clear
> > on which place.

> Why would adding integrity to the lsm= make sense? It's not an LSM.

> Sorry, but something is wrong here.
np. I explained that: try to boot with "ima_policy=tcb lsm=" or "ima_policy=tcb
lsm=whatever" (whatever != integrity).

Also have look at commit 92063f3ca73a ("integrity: double check iint_cache was
initialized") which explain why it's needed.

Kind regards,
Petr

[1] https://lore.kernel.org/linux-integrity/3ed2004413e0ac07c7bd6f10294d6b6fac6fdbf3.camel@linux.ibm.com/