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Subject: Re: [RFC PATCH 00/30] ima: Introduce IMA namespace
From:   James Bottomley <James.Bottomley@HansenPartnership.com>
To:     krzysztof.struczynski@huawei.com, linux-integrity@vger.kernel.org,
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Date:   Tue, 18 Aug 2020 09:19:31 -0700
In-Reply-To: <20200818152037.11869-1-krzysztof.struczynski@huawei.com>
References: <N> <20200818152037.11869-1-krzysztof.struczynski@huawei.com>
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On Tue, 2020-08-18 at 17:20 +0200, krzysztof.struczynski@huawei.com
wrote:
> The measurement list remains global, with the assumption that there
> is only one TPM in the system. Each IMA namespace has a unique ID,
> that allows to track measurements per IMA namespace. Processes in one
> namespace, have access only to the measurements from that namespace.
> The exception is made for the initial IMA namespace, whose processes
> have access to all entries.

So I think this can work in the use case where the system owner is
responsible for doing the logging and attestation and the tenants just
trust the owner without requiring an attestation.  However, in a multi-
tenant system you need a way for the attestation to be per-container
(because the combined list of who executed what would be a security
leak between tenants).  Since we can't virtualise the PCRs without
introducing a vtpm this is going to require a vtpm infrastructure like
that used for virtual machines and then we can do IMA logging per
container.

I don't think the above has to be in your first patch set, we just have
to have an idea of how it could be done to show that nothing in this
patch set precludes a follow on from doing this.

James