On Wed, 2018-04-18 at 15:12 -0500, Eric W. Biederman wrote: > Mimi Zohar <zohar@xxxxxxxxxxxxxxxxxx> writes: > > > On Wed, 2018-04-18 at 09:09 -0700, John Johansen wrote: > >> On 04/13/2018 09:25 AM, Mimi Zohar wrote: > >> > [Cc'ing John Johansen] > >> > > >> > On Tue, 2018-03-27 at 18:01 -0500, Eric W. Biederman wrote: > >> > [...] > >> >> As such I expect the best way to create the ima namespace is by simply > >> >> writing to securityfs/imafs. Possibly before the user namespace is > >> >> even unshared. That would allow IMA to keep track of things from > >> >> before a container is created. > >> > > >> > >> I do think this is generally the right approach for LSMs when looking > >> forward to LSM stacking and more LSMs. > >> > >> > >> > My initial thought was to stage IMA namespacing with just IMA-audit > >> > first, followed by either IMA-measurement or IMA-appraisal. This > >> > would allow us to get the basic IMA namespacing framework working and > >> > defer dealing with the securityfs related namespacing of the IMA > >> > policy and measurement list issues to later. > >> > > >> > By tying IMA namespacing to a securityfs ima/unshare file, we would > >> > need to address the securityfs issues first. > >> > > >> > >> well it depends on what you want to do. It would be possible to have > >> a simple file (not a jump link) within securityfs that IMA could use > >> without having to deal with all the securityfs issues first. However it > >> does require that securityfs (not necessarily imafs) be visible within > >> the mount namespace of the task doing the setup. > > > > Eric, would you be OK with that? > > Roughly. My understanding is that you have to have a write to some > filesystem to set the ima policy. > > I was expecting having to write an "create ima namespace" value > to the filesystem would not be any special effort. > > Now it sounds like providing the "create an ima namespace" is going to > be a special case, and that does not sound correct. This is not any different than any of the other security/ima/ files (eg. policy, ascii_runtime_measurements, ...). The next IMA namespacing stage would add support for these files. Mimi
