Re: [PATCH v3 0/9] bpf-lsm: Extend interoperability with IMA

KP Singh
2022-03-07T13:18:13Z

On Mon, Mar 7, 2022 at 3:57 AM Mimi Zohar <zohar@linux.ibm.com> wrote:
>
> On Thu, 2022-03-03 at 14:39 -0800, Alexei Starovoitov wrote:
>
> > . There is no such thing as "eBPF modules". There are BPF programs.
> > They cannot be signed the same way as kernel modules.
> > We've been working on providing a way to sign them for more
> > than a year now. That work is still ongoing.
> >
> > . IMA cannot be used for integrity check of BPF programs for the same
> > reasons why kernel module like signing cannot be used.
>
> I assume the issue isn't where the signature is stored (e.g. appended,
> xattr), but of calculating the hash. Where is the discussion taking

This has the relevant background: https://lwn.net/Articles/853489/

We had some more discussions in one of our BSC meeting:

https://github.com/ebpf-io/bsc/blob/master/minutes.md

and we expect the discussions to continue over conferences this year
(e.g. LSF/MM/BPF, Linux Plumbers). As I mentioned on another thread
we don't have to wait for conferences and we can discuss this in the BPF
office hours. Please feel free to add an agenda at:

https://docs.google.com/spreadsheets/d/1LfrDXZ9-fdhvPEp_LHkxAMYyxxpwBXjywWa0AejEveU/edit#gid=0

(best is to give some notice so that interested folks can join).

> place? Are there any summaries of what has been discussed?
>
> FYI, IMA isn't limited to measuring files. Support was added for
> buffer measurements (e.g kexec boot command line, certificates) and
> measuring kernel critical data (e.g. SELinux in memory policy & state,
> device mapper).

Nice. I need to look at how this is implemented.

- KP

>
> thanks,
>
> Mimi
>