On Jan 15, 2024 Roberto Sassu [off-list ref] wrote:

IMA and EVM are not effectively LSMs, especially due to the fact that in
the past they could not provide a security blob while there is another LSM
active.

That changed in the recent years, the LSM stacking feature now makes it
possible to stack together multiple LSMs, and allows them to provide a
security blob for most kernel objects. While the LSM stacking feature has
some limitations being worked out, it is already suitable to make IMA and
EVM as LSMs.

The main purpose of this patch set is to remove IMA and EVM function calls,
hardcoded in the LSM infrastructure and other places in the kernel, and to
register them as LSM hook implementations, so that those functions are
called by the LSM infrastructure like other regular LSMs.

Thanks Roberto, this is looking good.  I appreciate all the work you've
put into making this happen; when I first mentioned this idea I figured
it would be something that would happen much farther into the future, I
wasn't expecting to see you pick this up and put in the work to make it
happen - thank you.

I had some pretty minor comments but I think the only thing I saw that
I think needs a change/addition is a comment in the Makefile regarding
the IMA/EVM ordering; take a look and let me know what you think.

There are also a few patches in the patchset that don't have an
ACK/review tag from Mimi, although now that you are co-maininting IMA/EVM
with Mimi I don't know if that matters.  If the two of you can let me
know how you want me to handle LSM patches that are IMA/EVM related I
would appreciate it (two ACKs, one or other, something else?).

Once you add a Makefile commane and we sort out the IMA/EVM approval
process I think we're good to get this into linux-next.  A while back
Mimi and I had a chat offline and if I recall everything correctly she
preferred that I take this patchset via the LSM tree.  I don't have a
problem with that, and to be honest I would probably prefer
that too, but I wanted to check with everyone that is still the case.
Just in case, I've added my ACKs/reviews to this patchset in case this
needs to be merged via the integrity tree.

--
paul-moore.com