From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mummy.ncsc.mil (mummy.ncsc.mil [144.51.88.129]) by tarius.tycho.ncsc.mil (8.13.1/8.13.1) with ESMTP id n2BHjRsO014545 for ; Wed, 11 Mar 2009 13:45:27 -0400 Received: from house.lunarmania.com (jazzhorn.ncsc.mil [144.51.5.9]) by mummy.ncsc.mil (8.12.10/8.12.10) with ESMTP id n2BHjQFt003427 for ; Wed, 11 Mar 2009 17:45:26 GMT Received: from 78-3-249-56.adsl.net.t-com.hr ([78.3.249.56] helo=[192.168.1.2]) by house.lunarmania.com with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.69) (envelope-from ) id 1LhSUV-0004xE-Fg for selinux@tycho.nsa.gov; Wed, 11 Mar 2009 10:45:16 -0700 Message-ID: <49B7F893.9040706@rubix.com> Date: Wed, 11 Mar 2009 18:44:51 +0100 From: Andy Warner MIME-Version: 1.0 To: SELinux List Subject: Significance of the level on a port configuration Content-Type: multipart/alternative; boundary="------------060104000407010500050202" Sender: owner-selinux@tycho.nsa.gov List-Id: selinux@tycho.nsa.gov This is a multi-part message in MIME format. --------------060104000407010500050202 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Can someone give me a quick overview of the significance (i.e., the MLS behavior) of the port level for SELinux. I am attempting to have two connection from untrusted hosts that are statically labeled (with netlabelctl) one at high (s0) and one at low (s1). Both connections will be made over the same port number. The service accepting the connections runs at SystemHigh on Fedora 9 with MLS policy. What difference does the level of the port make ? Assume all TE rules are satisfied for the context of my question. Thanks, Andy --------------060104000407010500050202 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Can someone give me a quick overview of the significance (i.e., the MLS behavior) of the port level for SELinux.

I am attempting to have two connection from untrusted hosts that are statically labeled (with netlabelctl) one at high (s0) and one at low (s1). Both connections will be made over the same port number. The service accepting the connections runs at SystemHigh on Fedora 9 with MLS policy. What difference does the level of the port make ? Assume all TE rules are satisfied for the context of my question.

Thanks,

Andy

--------------060104000407010500050202-- -- This message was distributed to subscribers of the selinux mailing list. If you no longer wish to subscribe, send mail to majordomo@tycho.nsa.gov with the words "unsubscribe selinux" without quotes as the message. From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: Significance of the level on a port configuration From: Stephen Smalley To: Andy Warner Cc: SELinux List In-Reply-To: <49B7F893.9040706@rubix.com> References: <49B7F893.9040706@rubix.com> Content-Type: text/plain Date: Wed, 11 Mar 2009 13:47:19 -0400 Message-Id: <1236793639.14649.67.camel@localhost.localdomain> Mime-Version: 1.0 Sender: owner-selinux@tycho.nsa.gov List-Id: selinux@tycho.nsa.gov On Wed, 2009-03-11 at 18:44 +0100, Andy Warner wrote: > Can someone give me a quick overview of the significance (i.e., the > MLS behavior) of the port level for SELinux. > > I am attempting to have two connection from untrusted hosts that are > statically labeled (with netlabelctl) one at high (s0) and one at low > (s1). Both connections will be made over the same port number. The > service accepting the connections runs at SystemHigh on Fedora 9 with > MLS policy. What difference does the level of the port make ? Assume > all TE rules are satisfied for the context of my question. > I don't think the port level should make any difference. Are there any MLS constraints defined on any of the permission checks that are based on port contexts? > -- Stephen Smalley National Security Agency -- This message was distributed to subscribers of the selinux mailing list. If you no longer wish to subscribe, send mail to majordomo@tycho.nsa.gov with the words "unsubscribe selinux" without quotes as the message. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Moore To: Andy Warner Subject: Re: Significance of the level on a port configuration Date: Thu, 12 Mar 2009 11:07:27 -0400 Cc: Stephen Smalley , SELinux List References: <49B7F893.9040706@rubix.com> <1236793639.14649.67.camel@localhost.localdomain> In-Reply-To: <1236793639.14649.67.camel@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-15" Message-Id: <200903121107.27468.paul.moore@hp.com> Sender: owner-selinux@tycho.nsa.gov List-Id: selinux@tycho.nsa.gov On Wednesday 11 March 2009 01:47:19 pm Stephen Smalley wrote: > On Wed, 2009-03-11 at 18:44 +0100, Andy Warner wrote: > > Can someone give me a quick overview of the significance (i.e., the > > MLS behavior) of the port level for SELinux. > > > > I am attempting to have two connection from untrusted hosts that are > > statically labeled (with netlabelctl) one at high (s0) and one at low > > (s1). Both connections will be made over the same port number. The > > service accepting the connections runs at SystemHigh on Fedora 9 with > > MLS policy. What difference does the level of the port make ? Assume > > all TE rules are satisfied for the context of my question. > > I don't think the port level should make any difference. Are there any > MLS constraints defined on any of the permission checks that are based > on port contexts? Using the new network access controls there is no specific check against the port label, only the network interface and node (both of which just recently had the MLS constraints added). -- paul moore linux @ hp -- This message was distributed to subscribers of the selinux mailing list. If you no longer wish to subscribe, send mail to majordomo@tycho.nsa.gov with the words "unsubscribe selinux" without quotes as the message. From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: Significance of the level on a port configuration From: Stephen Smalley To: Paul Moore Cc: Andy Warner , SELinux List In-Reply-To: <200903121107.27468.paul.moore@hp.com> References: <49B7F893.9040706@rubix.com> <1236793639.14649.67.camel@localhost.localdomain> <200903121107.27468.paul.moore@hp.com> Content-Type: text/plain Date: Thu, 12 Mar 2009 11:09:26 -0400 Message-Id: <1236870566.22058.117.camel@localhost.localdomain> Mime-Version: 1.0 Sender: owner-selinux@tycho.nsa.gov List-Id: selinux@tycho.nsa.gov On Thu, 2009-03-12 at 11:07 -0400, Paul Moore wrote: > On Wednesday 11 March 2009 01:47:19 pm Stephen Smalley wrote: > > On Wed, 2009-03-11 at 18:44 +0100, Andy Warner wrote: > > > Can someone give me a quick overview of the significance (i.e., the > > > MLS behavior) of the port level for SELinux. > > > > > > I am attempting to have two connection from untrusted hosts that are > > > statically labeled (with netlabelctl) one at high (s0) and one at low > > > (s1). Both connections will be made over the same port number. The > > > service accepting the connections runs at SystemHigh on Fedora 9 with > > > MLS policy. What difference does the level of the port make ? Assume > > > all TE rules are satisfied for the context of my question. > > > > I don't think the port level should make any difference. Are there any > > MLS constraints defined on any of the permission checks that are based > > on port contexts? > > Using the new network access controls there is no specific check against the > port label, only the network interface and node (both of which just recently > had the MLS constraints added). name_bind/name_connect are still port-based, but there are no MLS constraints on them. The older per-packet send_msg/recv_msg checks are only applied if compat_net=1. send_msg has no MLS constraint. recv_msg is included in the socket "read" ops MLS constraint for reasons unclear to me; that seems like a mistake. -- Stephen Smalley National Security Agency -- This message was distributed to subscribers of the selinux mailing list. If you no longer wish to subscribe, send mail to majordomo@tycho.nsa.gov with the words "unsubscribe selinux" without quotes as the message. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Moore To: Stephen Smalley Subject: Re: Significance of the level on a port configuration Date: Thu, 12 Mar 2009 11:24:27 -0400 Cc: Andy Warner , SELinux List References: <49B7F893.9040706@rubix.com> <200903121107.27468.paul.moore@hp.com> <1236870566.22058.117.camel@localhost.localdomain> In-Reply-To: <1236870566.22058.117.camel@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-15" Message-Id: <200903121124.27596.paul.moore@hp.com> Sender: owner-selinux@tycho.nsa.gov List-Id: selinux@tycho.nsa.gov On Thursday 12 March 2009 11:09:26 am Stephen Smalley wrote: > On Thu, 2009-03-12 at 11:07 -0400, Paul Moore wrote: > > On Wednesday 11 March 2009 01:47:19 pm Stephen Smalley wrote: > > > On Wed, 2009-03-11 at 18:44 +0100, Andy Warner wrote: > > > > Can someone give me a quick overview of the significance (i.e., the > > > > MLS behavior) of the port level for SELinux. > > > > > > > > I am attempting to have two connection from untrusted hosts that are > > > > statically labeled (with netlabelctl) one at high (s0) and one at low > > > > (s1). Both connections will be made over the same port number. The > > > > service accepting the connections runs at SystemHigh on Fedora 9 with > > > > MLS policy. What difference does the level of the port make ? Assume > > > > all TE rules are satisfied for the context of my question. > > > > > > I don't think the port level should make any difference. Are there any > > > MLS constraints defined on any of the permission checks that are based > > > on port contexts? > > > > Using the new network access controls there is no specific check against > > the port label, only the network interface and node (both of which just > > recently had the MLS constraints added). > > name_bind/name_connect are still port-based, but there are no MLS > constraints on them. I got the impression that Andy was interested in port based MLS constraints in the context of per-packet access control. > The older per-packet send_msg/recv_msg checks are only applied if > compat_net=1. send_msg has no MLS constraint. recv_msg is included in > the socket "read" ops MLS constraint for reasons unclear to me; that > seems like a mistake. I don't know of the reasoning behind that decision either, but this will be less of an issue in the future as the compat_net code will be going away soon. -- paul moore linux @ hp -- This message was distributed to subscribers of the selinux mailing list. If you no longer wish to subscribe, send mail to majordomo@tycho.nsa.gov with the words "unsubscribe selinux" without quotes as the message.