Re: [PATCH V5 0/5] audit by executable name

Richard Guy Briggs
2014-10-29T21:54:42Z

On 14/10/29, Steve Grubb wrote:
> On Wednesday, October 29, 2014 03:48:40 PM Richard Guy Briggs wrote:
> > On 14/10/21, Paul Moore wrote:
> > > > > Can anyone think of anything else that might be affected by this?
> > > >
> > > > No one uses this stuff, just change it.
> > >
> > > Yes, but I feel like I need to at least ask the question; how much
> > > attention I pay to the answers is something else ...
> >
> > I'm still skeptical this won't blow up... Like the capabilities bitmap
> > did. I suspect there isn't agreement on what constitutes a feature.
>
> Anything major that user space would have to know about to determine if its
> supported. If you don't know, just ask if we need to add a bit to the bitmap.
> Some examples, adding the object comparison engine, adding the loginuid-
> immutable feature, if we added filtering on TTY that would also qualify (not
> asking for that). Otherwise, user space get EINVAL on the netlink operation
> which is not useful in explaining why the command was rejected.

Well, I guess this falls under Linus' "thou shalt not break userspace",
but it would certainly be tempting to change some of those to
EOPNOTSUPP.

> > We just added a set/get features bitmap a year ago for things to be turned
> > on/off and locked... How does this features bitmap fit in with that
> > features config?
>
> I think of that as commanding the features, not determining if they exist.

Which partly addresses another thing that occured to me which was that
there could be overlap between the two. status.version will have more
capacity due to only one bit needed per feature.

> > I don't disagree that a bitmap would be more useful for various
> > distributions to pick and choose that which they choose to support over
> > a version number that won't tell the whole story.
>
> I also can be used to allow deprecation in a controlled way such that helpful
> messages are given to the system admin.

That would work only for new things added, enabled explicitly with that
bit set in the bitfield.

> -Steve

- RGB

--
Richard Guy Briggs <rbriggs@redhat.com>
Senior Software Engineer, Kernel Security, AMER ENG Base Operating Systems, Red Hat
Remote, Ottawa, Canada
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