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

From: Roberto Sassu <[email-masked]>
Date: Thu, 3 Mar 2022 10:07:59 +0000

> From: Alexei Starovoitov [mailto:[email-masked]]
> Sent: Wednesday, March 2, 2022 11:21 PM
> On Wed, Mar 02, 2022 at 12:13:55PM +0100, Roberto Sassu wrote:
> > Extend the interoperability with IMA, to give wider flexibility for the
> > implementation of integrity-focused LSMs based on eBPF.
> >
> > Patch 1 fixes some style issues.
> >
> > Patches 2-6 give the ability to eBPF-based LSMs to take advantage of the
> > measurement capability of IMA without needing to setup a policy in IMA
> > (those LSMs might implement the policy capability themselves).
> >
> > Patches 7-9 allow eBPF-based LSMs to evaluate files read by the kernel.
> >
> > Changelog
> >
> > v2:
> > - Add better description to patch 1 (suggested by Shuah)
> > - Recalculate digest if it is not fresh (when IMA_COLLECTED flag not set)
> > - Move declaration of bpf_ima_file_hash() at the end (suggested by
> >   Yonghong)
> > - Add tests to check if the digest has been recalculated
> > - Add deny test for bpf_kernel_read_file()
> > - Add description to tests
> >
> > v1:
> > - Modify ima_file_hash() only and allow the usage of the function with the
> >   modified behavior by eBPF-based LSMs through the new function
> >   bpf_ima_file_hash() (suggested by Mimi)
> > - Make bpf_lsm_kernel_read_file() sleepable so that bpf_ima_inode_hash()
> >   and bpf_ima_file_hash() can be called inside the implementation of
> >   eBPF-based LSMs for this hook
> >
> > Roberto Sassu (9):
> >   ima: Fix documentation-related warnings in ima_main.c
> >   ima: Always return a file measurement in ima_file_hash()
> >   bpf-lsm: Introduce new helper bpf_ima_file_hash()
> >   selftests/bpf: Move sample generation code to ima_test_common()
> >   selftests/bpf: Add test for bpf_ima_file_hash()
> >   selftests/bpf: Check if the digest is refreshed after a file write
> >   bpf-lsm: Make bpf_lsm_kernel_read_file() as sleepable
> >   selftests/bpf: Add test for bpf_lsm_kernel_read_file()
> >   selftests/bpf: Check that bpf_kernel_read_file() denies reading IMA
> >     policy
> 
> We have to land this set through bpf-next.
> Please get the Acks for patches 1 and 2, so we can proceed.

Ok. Mimi, do you have time to have a look at those patches?

Thanks

Roberto

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