From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH] af_netlink: force credentials passing [CVE-2012-3520]
Date: Tue, 21 Aug 2012 14:53:38 -0700 (PDT)
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From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Tue, 21 Aug 2012 18:21:17 +0200

> From: Eric Dumazet <edumazet@google.com>
> 
> Pablo Neira Ayuso discovered that avahi and 
> potentially NetworkManager accept spoofed Netlink messages because of a 
> kernel bug.  The kernel passes all-zero SCM_CREDENTIALS ancillary data 
> to the receiver if the sender did not provide such data, instead of not 
> including any such data at all or including the correct data from the 
> peer (as it is the case with AF_UNIX).
> 
> This bug was introduced in commit 16e572626961
> (af_unix: dont send SCM_CREDENTIALS by default)
> 
> This patch forces passing credentials for netlink, as
> before the regression.
> 
> Another fix would be to not add SCM_CREDENTIALS in
> netlink messages if not provided by the sender, but it
> might break some programs.
> 
> With help from Florian Weimer & Petr Matousek
> 
> This issue is designated as CVE-2012-3520
> 
> Signed-off-by: Eric Dumazet <edumazet@google.com>

Applied and queued up for -stable, thanks Eric.