From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jiri Olsa <jolsa@redhat.com>
Subject: Re: [RFC] bpf: Emit audit messages upon successful prog load and
 unload
Date: Wed, 4 Dec 2019 15:02:51 +0100
Message-ID: <20191204140251.GA11548@krava>
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To: Paul Moore <paul@paul-moore.com>
Cc: Jiri Olsa <jolsa@kernel.org>, Alexei Starovoitov <ast@kernel.org>, Daniel Borkmann <daniel@iogearbox.net>, netdev@vger.kernel.org, bpf@vger.kernel.org, linux-audit@redhat.com, Andrii Nakryiko <andriin@fb.com>, Yonghong Song <yhs@fb.com>, Martin KaFai Lau <kafai@fb.com>, Jakub Kicinski <jakub.kicinski@netronome.com>, Steve Grubb <sgrubb@redhat.com>, David Miller <davem@redhat.com>, Eric Paris <eparis@redhat.com>, Jiri Benc <jbenc@redhat.com>
List-Id: linux-audit@redhat.com

On Mon, Dec 02, 2019 at 06:00:14PM -0500, Paul Moore wrote:

SNIP

> > +
> > +static void bpf_audit_prog(const struct bpf_prog *prog, enum bpf_audit=
 op)
> > +{
> > +       struct audit_buffer *ab;
> > +
> > +       if (audit_enabled =3D=3D AUDIT_OFF)
> > +               return;
>=20
> I think you would probably also want to check the results of
> audit_dummy_context() here as well, see all the various audit_XXX()
> functions in include/linux/audit.h as an example.  You'll see a
> pattern similar to the following:
>=20
> static inline void audit_foo(...)
> {
>   if (unlikely(!audit_dummy_context()))
>     __audit_foo(...)
> }
>=20
> > +       ab =3D audit_log_start(audit_context(), GFP_ATOMIC, AUDIT_BPF);
> > +       if (unlikely(!ab))
> > +               return;
> > +       audit_log_format(ab, "prog-id=3D%u op=3D%s",
> > +                        prog->aux->id, bpf_audit_str[op]);
>=20
> Is it worth putting some checks in here to make sure that you don't
> blow past the end of the bpf_audit_str array?

forgot answer this one..  there are only 2 callers:

  bpf_audit_prog(prog, BPF_AUDIT_UNLOAD);
  bpf_audit_prog(prog, BPF_AUDIT_LOAD);

that's not going to change any time soon,
so I dont think we don't need such check

jirka