netdev - Re: GTSM and TCP accept problem

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: <20100814.221258.35029372.davem@davemloft.net>
Date:	Sat, 14 Aug 2010 22:12:58 -0700 (PDT)
From:	David Miller <davem@...emloft.net>
To:	shemminger@...tta.com
Cc:	dada1@...mosbay.com, herbert@...dor.apana.org.au,
	netdev@...r.kernel.org
Subject: Re: GTSM and TCP accept problem

From: Stephen Hemminger <shemminger@...tta.com>
Date: Sat, 14 Aug 2010 21:46:34 -0400

> The implementation of Generalized TTL Security has a problem
> on the TCP accept side. Since there can be different number of
> hops for each peer, the listener ends up doing
> 
>    socket
>    bind
>    set TTL to 255
>    listen
>    while (nfd = accept(peer)) {
>      info = lookup(peer)
>      set MINTTL to 255 - info->ttl_hops

Surely when creating the initial listening socket we should use the
minimum TTL over the set of peers right?

That surely takes most of the fun out of this problem for the
attacker.
--
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