On Sun, May 17, 2020 at 10:15 AM Richard Guy Briggs <rgb(a)redhat.com> wrote:
On 2020-04-28 18:25, Paul Moore wrote:
> On Wed, Apr 22, 2020 at 5:40 PM Richard Guy Briggs <rgb(a)redhat.com> wrote:
> > Some table unregister actions seem to be initiated by the kernel to
> > garbage collect unused tables that are not initiated by any userspace
> > actions. It was found to be necessary to add the subject credentials to
> > cover this case to reveal the source of these actions. A sample record:
> >
> > type=NETFILTER_CFG msg=audit(2020-03-11 21:25:21.491:269) : table=nat
family=bridge entries=0 op=unregister pid=153 uid=root auid=unset tty=(none) ses=unset
subj=system_u:system_r:kernel_t:s0 comm=kworker/u4:2 exe=(null)
>
> [I'm going to comment up here instead of in the code because it is a
> bit easier for everyone to see what the actual impact might be on the
> records.]
>
> Steve wants subject info in this case, okay, but let's try to trim out
> some of the fields which simply don't make sense in this record; I'm
> thinking of fields that are unset/empty in the kernel case and are
> duplicates of other records in the userspace/syscall case. I think
> that means we can drop "tty", "ses", "comm", and
"exe" ... yes?
>
> While "auid" is a potential target for removal based on the
> dup-or-unset criteria, I think it falls under Steve's request for
> subject info here, even if it is garbage in this case.
Can you explain why auid falls under this criteria but ses does not if
both are unset?
"While "auid" is a potential target for removal based on the
dup-or-unset criteria, I think it falls under Steve's request for
subject info here, even if it is garbage in this case."
It's a concession to Steve. As I mentioned previously, I think the
subject info is bogus in this case; either it is valid and we get it
from the SYSCALL record or it simply isn't present in any meaningful
way.
--
paul moore
www.paul-moore.com