Re: [PATCH RFC bpf-next 0/4] audit: Expose audit subsystem to BPF LSM programs via BPF kfuncs

Alexei Starovoitov
2026-03-18T20:55:24Z

On Wed, Mar 18, 2026 at 10:49 AM Frederick Lawler <fred@cloudflare.com> wrote:
>
> Hi Alexei,
>
> On Tue, Mar 17, 2026 at 06:15:59PM -0700, Alexei Starovoitov wrote:
> > On Mon, Mar 16, 2026 at 7:44 PM Kumar Kartikeya Dwivedi
> > <memxor@gmail.com> wrote:
> > >
> > > On Wed, 11 Mar 2026 at 22:31, Frederick Lawler <fred@cloudflare.com> wrote:
> > > >
> > > > The motivation behind the change is to give BPF LSM developers the
> > > > ability to report accesses via the audit subsystem much like how LSMs
> > > > operate today.
> >
> > Sure, but bpf lsm-s don't need to follow such conventions.
> > audit is nothing but a message passing from kernel to user space
> > and done in a very inefficient way by wrapping strings into skb/netlink.
> > bpf progs can do this message passing already via various ways:
> > perfbuf, ringbuf, streams.
> > Teach your user space to consume one of them.
>
> Audit provides additional functionality by keeping messages close to the
> syscall, and in-line with other messages for that syscall. Aside from
> that, BPF is arguably too flexible. I'm sure it's already understood,
> but the idea here is to reduce bespoke logging implementations and reduce
> attack surface for violation reporting. Audit is already provided by the
> kernel and a well leveraged pipeline.

Sorry, I don't buy any of these arguments.
Nack.