netdev - Re: [PATCH 3/3] selinux: Add SELinux GTP support

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20200930110153.GT3871@nataraja>
Date:   Wed, 30 Sep 2020 13:01:53 +0200
From:   Harald Welte <laforge@...monks.org>
To:     Richard Haines <richard_c_haines@...nternet.com>
Cc:     selinux@...r.kernel.org, linux-security-module@...r.kernel.org,
        osmocom-net-gprs@...ts.osmocom.org, netdev@...r.kernel.org,
        stephen.smalley.work@...il.com, paul@...l-moore.com,
        pablo@...filter.org, jmorris@...ei.org
Subject: Re: [PATCH 3/3] selinux: Add SELinux GTP support

Hi Richard,

I don't fully understand in which context you need / use those SELinux GTP hooks,
however one comment from the point of view of somebody who is working on GGSN/P-GW
software using the GTP kernel module:

On Wed, Sep 30, 2020 at 10:49:34AM +0100, Richard Haines wrote:
> +selinux_gtp_dev_cmd()
> +~~~~~~~~~~~~~~~~~~~~~
> +Validate if the caller (current SID) and the GTP device SID have the required
> +permission to perform the operation. The GTP/SELinux permission map is
> +as follow::
> +
> +    GTP_CMD_NEWPDP = gtp { add }
> +    GTP_CMD_DELPDP = gtp { del }
> +    GTP_CMD_GETPDP = gtp { get }

Wouldn't it make sense to differentiate between:

a) add/del/get on the GTP netdev
b) add/del/get on the indivudual PDP wihin the GTP netdev

'a' is typically only created once at startup of a GGSN/P-GW software, or is
done even at system stat-up time.

'b' is performed frequently during runtime as the GGSN/P-GW function runs, as
subscribers attach to / detach from the cellular network.

By differentiating between those two, one could further constrain the permissions
required at runtime.

-- 
- Harald Welte <laforge@...monks.org>           http://laforge.gnumonks.org/
============================================================================
"Privacy in residential applications is a desirable marketing option."
                                                  (ETSI EN 300 175-7 Ch. A6)