From: Paul Moore <paul.moore@hp.com>
To: Eric Paris <eparis@redhat.com>
Cc: James Morris <jmorris@namei.org>,
linux-kernel@vger.kernel.org, selinux@tycho.nsa.gov,
netfilter-devel@vger.kernel.org, sds@tycho.nsa.gov,
jengelh@medozas.de, casey@schaufler-ca.com,
linux-security-module@vger.kernel.org, netfilter@vger.kernel.org,
mr.dash.four@googlemail.com
Subject: Re: [PATCH 3/6] secmark: export binary yes/no rather than kernel internal secid
Date: Mon, 27 Sep 2010 15:45:48 -0400 [thread overview]
Message-ID: <1285616748.4935.43.camel@sifl> (raw)
In-Reply-To: <1285615525.2815.76.camel@localhost.localdomain>
On Mon, 2010-09-27 at 15:25 -0400, Eric Paris wrote:
> On Mon, 2010-09-27 at 14:29 -0400, Paul Moore wrote:
> > On Mon, 2010-09-27 at 13:01 -0400, Eric Paris wrote:
> > > On Mon, 2010-09-27 at 10:50 +1000, James Morris wrote:
> > > > On Fri, 24 Sep 2010, Eric Paris wrote:
> > >
> > > > For the reasons above, I think the secctx string needs to be exported in
> > > > addition to this rather than instead of.
> > >
> > > I won't argue, I don't agree with your reasoning, but I'm not opposed to
> > > this result. We have 3 competing suggestions:
> > >
> > > Jan suggested we:
> > > completely eliminate secmark from procfs+netlink and only export secctx
> > > in netlink.
> > >
> > > Eric suggested we:
> > > completely eliminate secmark from procfs+netlink and then export secctx
> > > in procfs+netlink
> > >
> > > sounds like James suggested we:
> > > continue to export meaningless and confusing secmark from procfs+netlink
> > > and then export secctx in procfs+netlink as well.
> > >
> > > I'm going to implement James' idea and resend the patch series. Any
> > > strong objections?
> >
> > I apologize for not getting a chance to look at these patches sooner.
> > In general they look fine to me and my only real concern was addressed
> > by Pablo already (breaking userspace due to #define changes).
> >
> > As far as exporting the 32bit secid/secmark to userspace, I think that
> > is a mistake. James correctly points out that it does map to a LSM
> > specific value, e.g. SELinux and Smack security labels, but I don't
> > think he makes it clear that in the two LSMs that currently use secids
> > the mapping between the secid and the secctx is not constant; the secids
> > are transient values that will change with each boot in a manner that
> > userspace can not predict. For this reason, I think exporting the
> > secids is only going to cause users/admins grief, whereas exporting the
> > associated secctx should be a much more stable value and is likely what
> > the user/admin is expecting anyway.
>
> So it sounds to me like Paul agrees with me that exporting the SELinux
> sid as 'secmark=' was a bad idea. It's the whole reason this thread
> started, someone wanted to be able to translate and use that field (and
> instantly realized it was useless.)
>
> I see it as having 3 options. lets assume was have a packet with
> selinux sid=121 and selinux context=packet_t. We can
>
> 1) secmark=121 secctx=packet_t
> This continues to send secmark like we do and people might continue to
> be baffled by the 121.
>
> 2) secmark=1 secctx=packet_t
> This sends a secmark field to userspace so if an application which
> reads this exists (I doubt such an application actually exists in in the
> real world) it will still get all of the information it got before but
> noone will be baffled by what the number means. 1/0 is pretty obvious.
>
> 3) secctx=packet_t
> Smallest easiest, what my patches actually do. Could theoretically
> break some script that expected the field to be there, but any such
> script is already broken since that field can be easily compiled
> out......
>
> James, if you are adamant about #1 I'll resend, otherwise I'm sticking
> with #3.....
James, if you do feel strongly about door #1, can you provide a good
example of how someone might use the secid to do something useful in
userspace? I ask because I can't think of anything and it would be nice
to have the example on record for future work.
--
paul moore
linux @ hp
next prev parent reply other threads:[~2010-09-27 19:45 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-24 20:45 [PATCH 1/6] secmark: do not return early if there was no error Eric Paris
2010-09-24 20:45 ` [PATCH 2/6] secmark: make secmark object handling generic Eric Paris
2010-09-25 8:39 ` Pablo Neira Ayuso
2010-09-27 16:47 ` Eric Paris
2010-09-24 20:45 ` [PATCH 3/6] secmark: export binary yes/no rather than kernel internal secid Eric Paris
2010-09-25 8:41 ` Pablo Neira Ayuso
2010-09-27 16:44 ` Eric Paris
2010-09-27 0:50 ` James Morris
2010-09-27 17:01 ` Eric Paris
2010-09-27 18:29 ` Paul Moore
2010-09-27 19:25 ` Eric Paris
2010-09-27 19:45 ` Paul Moore [this message]
2010-09-27 22:48 ` Pablo Neira Ayuso
2010-09-28 0:00 ` Jan Engelhardt
2010-09-28 8:45 ` Mr Dash Four
2010-09-27 23:45 ` James Morris
2010-09-28 12:32 ` Casey Schaufler
2010-09-24 20:45 ` [PATCH 4/6] security: secid_to_secctx returns len when data is NULL Eric Paris
2010-09-27 13:49 ` Casey Schaufler
2010-09-24 20:45 ` [PATCH 5/6] conntrack: export lsm context rather than internal secid via netlink Eric Paris
2010-09-24 21:08 ` Jan Engelhardt
2010-09-27 11:01 ` Pablo Neira Ayuso
2010-09-27 16:51 ` Eric Paris
2010-09-24 20:45 ` [PATCH 6/6] secmark: export secctx, drop secmark in procfs Eric Paris
2010-09-24 21:01 ` [PATCH 1/6] secmark: do not return early if there was no error Jan Engelhardt
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=1285616748.4935.43.camel@sifl \
--to=paul.moore@hp.com \
--cc=casey@schaufler-ca.com \
--cc=eparis@redhat.com \
--cc=jengelh@medozas.de \
--cc=jmorris@namei.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-security-module@vger.kernel.org \
--cc=mr.dash.four@googlemail.com \
--cc=netfilter-devel@vger.kernel.org \
--cc=netfilter@vger.kernel.org \
--cc=sds@tycho.nsa.gov \
--cc=selinux@tycho.nsa.gov \
/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).