Re: [PATCH ghak90 V7 20/21] audit: add capcontid to set contid outside init_user_ns

From: Paul Moore
Date: Mon Oct 21 2019 - 15:53:35 EST


On Fri, Oct 18, 2019 at 9:39 PM Richard Guy Briggs <rgb@xxxxxxxxxx> wrote:
> On 2019-09-18 21:22, Richard Guy Briggs wrote:
> > Provide a mechanism similar to CAP_AUDIT_CONTROL to explicitly give a
> > process in a non-init user namespace the capability to set audit
> > container identifiers.
> >
> > Use audit netlink message types AUDIT_GET_CAPCONTID 1027 and
> > AUDIT_SET_CAPCONTID 1028. The message format includes the data
> > structure:
> > struct audit_capcontid_status {
> > pid_t pid;
> > u32 enable;
> > };
>
> Paul, can I get a review of the general idea here to see if you're ok
> with this way of effectively extending CAP_AUDIT_CONTROL for the sake of
> setting contid from beyond the init user namespace where capable() can't
> reach and ns_capable() is meaningless for these purposes?

I think my previous comment about having both the procfs and netlink
interfaces apply here. I don't see why we need two different APIs at
the start; explain to me why procfs isn't sufficient. If the argument
is simply the desire to avoid mounting procfs in the container, how
many container orchestrators can function today without a valid /proc?

--
paul moore
www.paul-moore.com