netdev - Re: [PATCH net] sit: Set skb->protocol properly in ipip6_tunnel

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: <20161128.150030.370640725503436541.davem@davemloft.net>
Date:   Mon, 28 Nov 2016 15:00:30 -0500 (EST)
From:   David Miller <davem@...emloft.net>
To:     eric.dumazet@...il.com
Cc:     alexander.duyck@...il.com, sfr@...b.auug.org.au, elicooper@....com,
        netdev@...r.kernel.org
Subject: Re: [PATCH net] sit: Set skb->protocol properly in
 ipip6_tunnel_xmit()

From: Eric Dumazet <eric.dumazet@...il.com>
Date: Mon, 28 Nov 2016 10:32:15 -0800

> On Mon, 2016-11-28 at 10:17 -0800, Eric Dumazet wrote:
> 
>> I was referring to Stephen bug report.
>> 
>> It appears that Eli changelog was not very precise, because his bug was
>> because of XFRM being involved.
>> 
>> xfrm_output() -> xfrm_output_gso() -> skb_gso_segment()
>> 
>> So XFRM calls skb_gso_segment() before ip_output() or
>> ip6_finish_output2() had a chance to change skb->protocol
> 
> So maybe the real fix would be to set skb->protocol at the right place,
> before xfrm can be called, instead of chasing all skb producers ;)

And the key for this would be dst_output() invocations.