From: Richard Guy Briggs <rgb@redhat.com>
To: Phil Sutter <phil@nwl.cc>, Steve Grubb <sgrubb@redhat.com>,
Linux-Audit Mailing List <linux-audit@redhat.com>,
LKML <linux-kernel@vger.kernel.org>,
netfilter-devel@vger.kernel.org, Paul Moore <paul@paul-moore.com>,
Ondrej Mosnacek <omosnace@redhat.com>,
fw@strlen.de, twoerner@redhat.com,
Eric Paris <eparis@parisplace.org>,
tgraf@infradead.org
Subject: Re: [PATCH ghak124 v3] audit: log nftables configuration change events
Date: Fri, 12 Feb 2021 15:54:40 -0500 [thread overview]
Message-ID: <20210212205440.GM3141668@madcap2.tricolour.ca> (raw)
In-Reply-To: <20210212121112.GA3158@orbyte.nwl.cc>
On 2021-02-12 13:11, Phil Sutter wrote:
> Hi,
>
> On Thu, Feb 11, 2021 at 04:02:55PM -0500, Steve Grubb wrote:
> > On Thursday, February 11, 2021 11:29:34 AM EST Paul Moore wrote:
> > > > If I'm not mistaken, iptables emits a single audit log per table, ipset
> > > > doesn't support audit at all. So I wonder how much audit logging is
> > > > required at all (for certification or whatever reason). How much
> > > > granularity is desired?
> >
> > <snip>
> >
> > > I believe the netfilter auditing was mostly a nice-to-have bit of
> > > functionality to help add to the completeness of the audit logs, but I
> > > could very easily be mistaken. Richard put together those patches, he
> > > can probably provide the background/motivation for the effort.
> >
> > There are certifications which levy requirements on information flow control.
> > The firewall can decide if information should flow or be blocked. Information
> > flow decisions need to be auditable - which we have with the audit target.
>
> In nftables, this is realized via 'log level audit' statement.
> Functionality should by all means be identical to that of xtables' AUDIT
> target.
>
> > That then swings in requirements on the configuration of the information flow
> > policy.
> >
> > The requirements state a need to audit any management activity - meaning the
> > creation, modification, and/or deletion of a "firewall ruleset". Because it
> > talks constantly about a ruleset and then individual rules, I suspect only 1
> > summary event is needed to say something happened, who did it, and the
> > outcome. This would be in line with how selinux is treated: we have 1 summary
> > event for loading/modifying/unloading selinux policy.
>
> So the central element are firewall rules for audit purposes and
> NETFILTER_CFG notifications merely serve asserting changes to those
> rules are noticed by the auditing system. Looking at xtables again, this
> seems coherent: Any change causes the whole table blob to be replaced
> (while others stay in place). So table replace/create is the most common
> place for a change notification. In nftables, the most common one is
> generation dump - all tables are treated as elements of the same
> ruleset, not individually like in xtables.
>
> Richard, assuming the above is correct, are you fine with reducing
> nftables auditing to a single notification per transaction then? I guess
> Florian sufficiently illustrated how this would be implemented.
Yes, that should be possible.
> > Hope this helps...
>
> It does, thanks a lot for the information!
>
> Thanks, Phil
- 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
prev parent reply other threads:[~2021-02-12 20:57 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-04 13:20 [PATCH ghak124 v3] audit: log nftables configuration change events Richard Guy Briggs
2020-06-04 17:03 ` Steve Grubb
2020-06-04 17:57 ` Richard Guy Briggs
2020-06-04 18:51 ` Steve Grubb
2020-06-24 0:34 ` Paul Moore
2020-06-24 10:03 ` Pablo Neira Ayuso
2020-06-24 12:34 ` Richard Guy Briggs
2020-06-24 13:03 ` Pablo Neira Ayuso
2020-06-24 13:26 ` Richard Guy Briggs
2021-02-11 15:16 ` Phil Sutter
2021-02-11 16:29 ` Paul Moore
2021-02-11 20:26 ` Richard Guy Briggs
2021-02-11 22:09 ` Florian Westphal
2021-02-17 23:41 ` Richard Guy Briggs
2021-02-18 8:22 ` Florian Westphal
2021-02-18 12:42 ` Richard Guy Briggs
2021-02-18 12:52 ` Florian Westphal
2021-02-18 13:28 ` Richard Guy Briggs
2021-02-18 13:41 ` Florian Westphal
2021-02-18 21:20 ` Richard Guy Briggs
2021-02-18 22:42 ` Florian Westphal
2021-02-19 6:26 ` Richard Guy Briggs
2021-02-19 19:25 ` Richard Guy Briggs
2021-02-12 20:48 ` Richard Guy Briggs
2021-02-11 21:02 ` Steve Grubb
2021-02-12 12:11 ` Phil Sutter
2021-02-12 20:54 ` Richard Guy Briggs [this message]
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