Re: [RFC PATCH 4/9] audit: add filtering for io_uring records

Richard Guy Briggs
2021-06-02T15:38:19Z

On 2021-06-01 21:40, Paul Moore wrote:
> On Mon, May 31, 2021 at 9:44 AM Richard Guy Briggs <rgb@redhat.com> wrote:
> > On 2021-05-30 11:26, Paul Moore wrote:
> > > On Fri, May 28, 2021 at 6:36 PM Richard Guy Briggs <rgb@redhat.com> wrote:
> > > > On 2021-05-21 17:50, Paul Moore wrote:
> > > > If we abuse the syscall infrastructure at first, we'd need a transition
> > > > plan to coordinate user and kernel switchover to seperate mechanisms for
> > > > the two to work together if the need should arise to have both syscall
> > > > and uring filters in the same rule.
> > >
> > > See my comments above, I don't currently see why we would ever want
> > > syscall and io_uring filtering to happen in the same rule. Please
> > > speak up if you can think of a reason why this would either be needed,
> > > or desirable for some reason.
> >
> > I think they can be seperate rules for now. Either a syscall rule
> > catching all io_uring ops can be added, or an io_uring rule can be added
> > to catch specific ops. The scenario I was thinking of was catching
> > syscalls of specific io_uring ops.
>
> Perhaps I'm misunderstand you, but that scenario really shouldn't
> exist. The io_uring ops function independently of syscalls; you can
> *submit* io_uring ops via io_uring_enter(), but they are not
> guaranteed to be dispatched synchronously (obviously), and given the
> cred shenanigans that can happen with io_uring there is no guarantee
> the filters would even be applicable.

That wasn't my understanding. There are a number of io_uring calls
starting with at least open that are currently synchronous (but may
become async in future) that we may want to single out which would be a
specific io_uring syscall with a specific io_uring opcode. I guess
that particular situation would be caught by the io_uring opcode
triggering an event that includes SYSCALL and URINGOP records.

> It isn't an issue of "can" the filters be separate, they *have* to be separate.

> paul moore

- RGB

--
Richard Guy Briggs <rgb@redhat.com>
Sr. S/W Engineer, Kernel Security, Base Operating Systems
Remote, Ottawa, Red Hat Canada
IRC: rgb, SunRaycer
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