From: Phil Sutter <phil@nwl.cc>
To: Steve Grubb <sgrubb@redhat.com>
Cc: Richard Guy Briggs <rgb@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 13:11:12 +0100 [thread overview]
Message-ID: <20210212121112.GA3158@orbyte.nwl.cc> (raw)
In-Reply-To: <4087569.ejJDZkT8p0@x2>
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.
> Hope this helps...
It does, thanks a lot for the information!
Thanks, Phil
next prev parent reply other threads:[~2021-02-12 12:12 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 [this message]
2021-02-12 20:54 ` Richard Guy Briggs
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210212121112.GA3158@orbyte.nwl.cc \
--to=phil@nwl.cc \
--cc=eparis@parisplace.org \
--cc=fw@strlen.de \
--cc=linux-audit@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=netfilter-devel@vger.kernel.org \
--cc=omosnace@redhat.com \
--cc=paul@paul-moore.com \
--cc=rgb@redhat.com \
--cc=sgrubb@redhat.com \
--cc=tgraf@infradead.org \
--cc=twoerner@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).