Re: [PATCH 5/5] LSM: Define workqueue for measuring security module state

Stephen Smalley
2020-06-15T13:33:55Z

On Fri, Jun 12, 2020 at 10:42 PM Lakshmi Ramasubramanian
<nramas@linux.microsoft.com> wrote:
>
> The data maintained by the security modules could be tampered with by
> malware. The LSM needs to periodically query the state of
> the security modules and measure the data when the state is changed.
>
> Define a workqueue for handling this periodic query and measurement.

Won't this make it difficult/impossible to predict the IMA PCR value?
Unless I missed it, you are going to end up measuring every N minutes
even if there was no change and therefore constantly be extending the
PCR. That will break attestation or sealing against the IMA PCR.