Re: [RFC PATCH 2/9] audit,io_uring,io-wq: add some basic audit support to io_uring

On Thu, Jun 3, 2021 at 11:54 AM Jens Axboe [off-list ref] wrote:

On 5/28/21 10:02 AM, Paul Moore wrote:

quoted

On Wed, May 26, 2021 at 4:19 PM Paul Moore [off-list ref] wrote:

quoted

... If we moved the _entry
and _exit calls into the individual operation case blocks (quick
openat example below) so that only certain operations were able to be
audited would that be acceptable assuming the high frequency ops were
untouched?  My initial gut feeling was that this would involve >50% of
the ops, but Steve Grubb seems to think it would be less; it may be
time to look at that a bit more seriously, but if it gets a NACK
regardless it isn't worth the time - thoughts?

  case IORING_OP_OPENAT:
    audit_uring_entry(req->opcode);
    ret = io_openat(req, issue_flags);
    audit_uring_exit(!ret, ret);
    break;

I wanted to pose this question again in case it was lost in the
thread, I suspect this may be the last option before we have to "fix"
things at the Kconfig level.  I definitely don't want to have to go
that route, and I suspect most everyone on this thread feels the same,
so I'm hopeful we can find a solution that is begrudgingly acceptable
to both groups.

Sorry for the lack of response here, but to sum up my order of
preference:

1) It's probably better to just make the audit an opt-out in io_op_defs
   for each opcode, and avoid needing boiler plate code for each op
   handler. The opt-out would ensure that new opcodes get it by default
   it someone doesn't know what it is, and the io_op_defs addition would
   mean that it's in generic code rather then in the handlers. Yes it's
   a bit slower, but it's saner imho.

2) With the above, I'm fine with adding this to io_uring. I don't think
   going the route of mutual exclusion in kconfig helps anyone, it'd
   be counter productive to both sides.

Hope that works and helps move this forward. I'll be mostly out of touch
the next week and a half, but wanted to ensure that I sent out my
(brief) thoughts before going away.

Thanks Jens.  I'll revise the patchset based on this (basically doing
an opt-out version of what you did on May 26th) and do a v2 post with
the other accumulated fixes/changes.  If there is anything else that
needs discussion/review I'm sure Pavel can help us out, he's been
helpful thus far.

--
paul moore
www.paul-moore.com