netdev - Re: macvlan/macvtap patch in patchwork

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: <4E825804.2010603@ll.mit.edu>
Date:	Tue, 27 Sep 2011 19:11:00 -0400
From:	"Ward, David - 0663 - MITLL" <david.ward@...mit.edu>
To:	David Miller <davem@...emloft.net>
CC:	"kaber@...sh.net" <kaber@...sh.net>,
	"netdev@...r.kernel.org" <netdev@...r.kernel.org>,
	"herbert@...dor.hengli.com.au" <herbert@...dor.hengli.com.au>,
	"krkumar2@...ibm.com" <krkumar2@...ibm.com>
Subject: Re: macvlan/macvtap patch in patchwork

On 27/09/11 15:14, David Miller wrote:
> Could you guys please review:
>
> 	http://patchwork.ozlabs.org/patch/115273/
>
> My gut instinct is that the current behavior is intentional, but since
> the patch submitter didn't describe exactly what the undesirable
> behavior is it's hard to tell what the patch is actually fixing.
>
> Thanks.

Sorry if my commit message was not descriptive enough -- I can revise it 
if you would like.

The macvlan and macvtap drivers both call macvlan_queue_xmit when 
sending outgoing frames.  In the case of unicast frames between 
macvlan/macvtap devices, we first forward the frame to the lowerdev, so 
that its network taps can see it.

The problem is that I was forwarding the frame to the lowerdev the wrong 
way, by calling vlan->forward which serves a different purpose.  
vlan->forward points to dev_forward_skb for macvlan (so the forwarding 
works fine), but it points to macvtap_forward for macvtap (which causes 
an oops when called here).  We need to always use dev_forward_skb to 
forward to a lowerdev.

David

Download attachment "smime.p7s" of type "application/pkcs7-signature" (5650 bytes)