netdev - Re: [PATCH 0/4] Prevent UDP tunnels from operating on garbage socket

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: <20150406.131700.185460014498109286.davem@davemloft.net>
Date:	Mon, 06 Apr 2015 13:17:00 -0400 (EDT)
From:	David Miller <davem@...emloft.net>
To:	tom@...bertland.com
Cc:	netdev@...r.kernel.org, netfilter-devel@...r.kernel.org,
	pablo@...filter.org, hannes@...essinduktion.org, jiri@...nulli.us
Subject: Re: [PATCH 0/4] Prevent UDP tunnels from operating on garbage
 socket

From: David Miller <davem@...emloft.net>
Date: Mon, 06 Apr 2015 12:41:14 -0400 (EDT)

> Tom if you are saying that skb->sk should be reset to the tunnel
> socket, that doesn't work and is completely broken.

Thinking some more, I think what you are missing is that deeper in the
ipv4/ipv6 transmit call chain we do things like sk_mc_loop() etc. on
the socket and we cannot just do it on skb->sk.

To make that work correctly we must pass the tunnel socket down
through the ipv4/ipv6 packet output paths, via netfilter hooks
if necessary.

I am also really disappointed with the call signature of the udp
tunnel send paths.  You have to be honest with yourself and agree
that something with 11 arguments is not a well designed interface.

Now that hopefully you can see that the socket is actually required,
can possibly use that to trim the function signature down for
udp_tunnel{,6}_xmit_skb()?

Worst case, make a "struct udp_tunnel_state" just like I made a "struct
nf_hook_state" for the netfilter hooks.

Thanks.
--
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