[CRIU] [PATCH v2] lsm: adds process attribute getter for Landlock

[Paul Moore]

On Thu, May 18, 2023 at 5:26 PM Casey Schaufler <casey at schaufler-ca.com> wrote:
> On 5/18/2023 1:45 PM, Shervin Oloumi wrote:
> > Adds a new getprocattr hook function to the Landlock LSM, which tracks
> > the landlocked state of the process. This is invoked when user-space
> > reads /proc/[pid]/attr/domain
>
> Please don't add a Landlock specific entry directly in the attr/
> directory. Add it only to attr/landlock.
>
> Also be aware that the LSM maintainer (Paul Moore) wants to move
> away from the /proc/.../attr interfaces in favor of a new system call,
> which is in review.

What Casey said above.

There is still some uncertainty around timing, and if we're perfectly
honest, acceptance of the new syscalls at the Linus level, but yes, I
would very much like to see the LSM infrastructure move away from
procfs and towards a syscall API.  Part of the reasoning is that the
current procfs API is ill-suited to handle the multiple, stacked LSMs
and the other part being the complexity of procfs in a namespaced
system.  If the syscall API is ultimately rejected, we will need to
revisit the idea of a procfs API, but even then I think we'll need to
make some changes to the current approach.

As I believe we are in the latter stages of review for the syscall
API, perhaps you could take a look and ensure that the current
proposed API works for what you are envisioning with Landlock?

-- 
paul-moore.com