Re: [PATCH ghak90 (was ghak32) V4 03/10] audit: log container info of syscalls

From: Richard Guy Briggs <rgb@redhat.com>
To: Paul Moore <paul@paul-moore.com>
Cc: containers@lists.linux-foundation.org, linux-api@vger.kernel.org,
	linux-audit@redhat.com, linux-fsdevel@vger.kernel.org,
	linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
	netfilter-devel@vger.kernel.org, ebiederm@xmission.com,
	luto@kernel.org, carlos@redhat.com, dhowells@redhat.com,
	viro@zeniv.linux.org.uk, simo@redhat.com,
	Eric Paris <eparis@parisplace.org>,
	Serge Hallyn <serge@hallyn.com>
Subject: Re: [PATCH ghak90 (was ghak32) V4 03/10] audit: log container info of syscalls
Date: Thu, 25 Oct 2018 08:22:52 -0400	[thread overview]
Message-ID: <20181025122252.dsqcmkguuro3krzg@madcap2.tricolour.ca> (raw)
In-Reply-To: <166a9dae538.280e.85c95baa4474aabc7814e68940a78392@paul-moore.com>

On 2018-10-25 07:13, Paul Moore wrote:
> On October 25, 2018 1:43:16 AM Richard Guy Briggs <rgb@redhat.com> wrote:
> > On 2018-10-24 16:55, Paul Moore wrote:
> >> On Wed, Oct 24, 2018 at 11:15 AM Richard Guy Briggs <rgb@redhat.com> wrote:
> >>> On 2018-10-19 19:16, Paul Moore wrote:
> >>>> On Sun, Aug 5, 2018 at 4:32 AM Richard Guy Briggs <rgb@redhat.com> wrote:
> >
> 
> ...
> 
> >
> >>>> However, I do care about the "op" field in this record.  It just
> >>>> doesn't make any sense; the way you are using it it is more of a
> >>>> context field than an operations field, and even then why is the
> >>>> context important from a logging and/or security perspective?  Drop it
> >>>> please.
> >>>
> >>> I'll rename it to whatever you like.  I'd suggest "ref=".  The reason I
> >>> think it is important is there are multiple sources that aren't always
> >>> obvious from the other records to which it is associated.  In the case
> >>> of ptrace and signals, there can be many target tasks listed (OBJ_PID)
> >>> with no other way to distinguish the matching audit container identifier
> >>> records all for one event.  This is in addition to the default syscall
> >>> container identifier record.  I'm not currently happy with the text
> >>> content to link the two, but that should be solvable (most obvious is
> >>> taret PID).  Throwing away this information seems shortsighted.
> >>
> >> It would be helpful if you could generate real audit events
> >> demonstrating the problems you are describing, as well as a more
> >> standard syscall event, so we can discuss some possible solutions.
> >
> > If the auditted process is in a container and it ptraces or signals
> > another process in a container, there will be two AUDIT_CONTAINER
> > records for the same event that won't be identified as to which record
> > belongs to which process or other record (SYSCALL vs 1+ OBJ_PID
> > records).  There could be many signals recorded, each with their own
> > OBJ_PID record.  The first is stored in the audit context and additional
> > ones are stored in a chained struct that can accommodate 16 entries each.
> >
> > (See audit_signal_info(), __audit_ptrace().)
> >
> > (As a side note, on code inspection it appears that a signal target
> > would get overwritten by a ptrace action if they were to happen in that
> > order.)
> 
> As requested above, please respond with real audit events generated by
> this patchset so that we can discuss possible solutions.

Ok, then we should be developping a test to test ptrace and signal
auditting in general since we don't have current experience/evidence
that those even work (or rip them out if not).

> 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