netdev - Re: [PATCH] cipso: handle CIPSO options correctly when NetLabel is disabled

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: <20120531.190705.3612500429295140.davem@davemloft.net>
Date:	Thu, 31 May 2012 19:07:05 -0400 (EDT)
From:	David Miller <davem@...emloft.net>
To:	pmoore@...hat.com
Cc:	netdev@...r.kernel.org, linux-security-module@...r.kernel.org,
	stable@...nel.org
Subject: Re: [PATCH] cipso: handle CIPSO options correctly when NetLabel is
 disabled

From: Paul Moore <pmoore@...hat.com>
Date: Thu, 31 May 2012 16:09:23 -0400

> When NetLabel is not enabled, e.g. CONFIG_NETLABEL=n, and the system
> receives a CIPSO tagged packet it is dropped (cipso_v4_validate()
> returns non-zero).  In most cases this is the correct and desired
> behavior, however, in the case where we are simply forwarding the
> traffic, e.g. acting as a network bridge, this becomes a problem.
> 
> This patch fixes the forwarding problem by providing the basic CIPSO
> validation code directly in ip_options_compile() without the need for
> the NetLabel or CIPSO code.  The new validation code can not perform
> any of the CIPSO option label/value verification that
> cipso_v4_validate() does, but it can verify the basic CIPSO option
> format.
> 
> The behavior when NetLabel is enabled is unchanged.
> 
> Signed-off-by: Paul Moore <pmoore@...hat.com>

I don't like this at all.

The only conclusion I can come to is that cipso_v4_validate() is doing
the wrong thing when NETLABEL is disabled.

There is never a good reason to crap all over a function with ifdefs.
This is especially true when it's being done to paper over a function
with poor semantics.

The whole idea is to abstract and put all of this kind of logic into
cipso_v4_validate().

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html