Hi Tushar, On Mon, 2021-02-08 at 15:22 -0500, Mimi Zohar wrote: > On Fri, 2021-01-29 at 16:45 -0800, Tushar Sugandhi wrote: > > IMA does not measure duplicate buffer data since TPM extend is a very > > expensive operation. However, in some cases for integrity critical > > data, the measurement of duplicate data is necessary to accurately > > determine the current state of the system. Eg, SELinux state changing > > from 'audit', to 'enforcing', and back to 'audit' again. In this > > example, currently, IMA will not measure the last state change to > > 'audit'. This limits the ability of attestation services to accurately > > determine the current state of the integrity critical data on the > > system. > > > > This series addresses this gap by providing the ability to measure > > duplicate entries for integrity critical data, driven by policy. > > The same reason for re-measuring buffer data is equally applicable to > files. In both cases, the file or the buffer isn't re-measured if it > already exists in the htable. Please don't limit this patch set to > just buffer data. Instead of making the change on a per measurement rule basis, disabling "htable" would be the simplest way of forcing re-measurements. All that would be needed is a new Kconfig (e.g. CONFIG_IMA_DISABLE_HTABLE) and the associated test in ima_add_template_entry(). thanks, Mimi
