Re: [PATCH bpf v3 2/2] selftests/bpf: fix and consolidate d_path LSM regression test

[Song Liu]

On Wed, Dec 3, 2025 at 8:34 PM Shuran Liu <electronlsr@xxxxxxxxx> wrote:
>
> Hi Song,
>
> Thanks for the review.
>
> > I don't get why we add this selftest here. It doesn't appear to be related to
> > patch 1/2.
>
> The regression that patch 1/2 fixes was originally hit by an LSM program
> calling bpf_d_path() from the bprm_check_security hook. The new subtest is a
> minimal reproducer for that scenario: without patch 1/2 the string comparison
> never matches due to verifier's faulty optimization, and with patch 1/2 it
> behaves correctly.

I somehow didn't reproduce this in my local tests. Thanks for the explanation.

Song