Re: [RFC PATCH v2 0/9] Add LSM access controls and auditing to io_uring

Richard Guy Briggs
2021-10-04T12:40:41Z

On 2021-10-03 19:21, Paul Moore wrote:
> On Sat, Oct 2, 2021 at 9:16 AM Steve Grubb <sgrubb@redhat.com> wrote:
> > On Thursday, September 9, 2021 8:58:58 PM EDT Richard Guy Briggs wrote:
> > > > I spent some time this morning/afternoon playing with the io_uring
> > > > audit filtering capability and with your audit userspace
> > > > ghau-iouring-filtering.v1.0 branch it appears to work correctly. Yes,
> > > > the userspace tooling isn't quite 100% yet (e.g. `auditctl -l` doesn't
> > > > map the io_uring ops correctly), but I know you mentioned you have a
> > > > number of fixes/improvements still as a work-in-progress there so I'm
> > > > not too concerned. The important part is that the kernel pieces look
> > > > to be working correctly.
> > >
> > > Ok, I have squashed and pushed the audit userspace support for iouring:
> > >
> > > https://github.com/rgbriggs/audit-userspace/commit/e8bd8d2ea8adcaa758024cb
> > > 9b8fa93895ae35eea
> > > https://github.com/linux-audit/audit-userspace/compare/master...rgbriggs:g
> > > hak-iouring-filtering.v2.1 There are test rpms for f35 here:
> > > http://people.redhat.com/~rbriggs/ghak-iouring/git-e8bd8d2-fc35/
> > >
> > > userspace v2 changelog:
> > > - check for watch before adding perm
> > > - update manpage to include filesystem filter
> > > - update support for the uring filter list: doc, -U op, op names
> > > - add support for the AUDIT_URINGOP record type
> > > - add uringop support to ausearch
> > > - add uringop support to aureport
> > > - lots of bug fixes
> > >
> > > "auditctl -a uring,always -S ..." will now throw an error and require
> > > "-U" instead.
> >
> > OK, now that the bug fix release is out of the way, let's start merging this
> > into user space. I think we should start with the code that let's auditd
> > write the record correctly and then the auditctl piece that inserts the rule
> > into the kernel. Those should be easy to merge.
> >
> > I see one section of code that mirrors all of the operations in ioring.h. I
> > thought that Paul only wanted to audit some of the operations and not all of
> > them. Did that change? Are we really going to allow auditing reads on ioring?
>
> Only certain io_uring operations are audited, you can see the patch
> here in the selinux/next tree (look for the io_op_defs struct changes
> and the "audit_skip" field):
>
> https://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux.git/commit/?h=next&id=5bd2182d58e9d9c6279b7a8a2f9b41add0e7f9cb

I understood that was the default, but that it could be changed by
userspace configuration? Now that I say this, I realize there is no API
to do so, but that could be added without breaking anything.

> 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
Voice: +1.647.777.2635, Internal: (81) 32635