netdev - Re: [PATCH] bridge: make bridge-nf-call-*tables default configurable

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: <20090701041034.GA29980@gondor.apana.org.au>
Date:	Wed, 1 Jul 2009 12:10:35 +0800
From:	Herbert Xu <herbert@...dor.apana.org.au>
To:	Jan Engelhardt <jengelh@...ozas.de>
Cc:	David Miller <davem@...emloft.net>, markmc@...hat.com,
	netdev@...r.kernel.org, kaber@...sh.net,
	netfilter-devel@...r.kernel.org
Subject: Re: [PATCH] bridge: make bridge-nf-call-*tables default
	configurable

On Wed, Jul 01, 2009 at 05:50:18AM +0200, Jan Engelhardt wrote:
> 
> On secondary thought, one could also argue that because conntrack 
> ignores the interface, two unrelated connections happening to be routed 
> through the same machine(*) are tracked as one, too.

Good point.  We really should make these risks much more explicit.

However, I still think the risk with bridging is higher, especially
in the presence of virtualisation.  Consider the scenario where you
have to VMs on the one host, each with a dedicated bridge with the
intention that neither should know anything about the other's
traffic.

With conntrack running as part of bridging, the traffic can now
cross over which is a serious security hole.

Cheers,
-- 
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <herbert@...dor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
--
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