[Bridge] [PATCH net] bridge: Prevent insertion of FDB entry with disallowed vlan

David Miller davem at davemloft.net
Mon Jun 2 20:38:51 UTC 2014


From: Vlad Yasevich <vyasevic at redhat.com>
Date: Mon, 02 Jun 2014 10:22:10 -0400

> On 05/30/2014 06:48 PM, David Miller wrote:
>> From: Toshiaki Makita <makita.toshiaki at lab.ntt.co.jp>
>> Date: Mon, 26 May 2014 15:15:53 +0900
>> 
>>> br_handle_local_finish() is allowing us to insert an FDB entry with
>>> disallowed vlan. For example, when port 1 and 2 are communicating in
>>> vlan 10, and even if vlan 10 is disallowed on port 3, port 3 can
>>> interfere with their communication by spoofed src mac address with
>>> vlan id 10.
>>>
>>> Note: Even if it is judged that a frame should not be learned, it should
>>> not be dropped because it is destined for not forwarding layer but higher
>>> layer. See IEEE 802.1Q-2011 8.13.10.
>>>
>>> Signed-off-by: Toshiaki Makita <makita.toshiaki at lab.ntt.co.jp>
>> 
>> In reference to Vlad's suggestion to try to reuse the logic of the
>> existing br_allowed_ingress() function, I don't think that's so
>> easy.
>> 
>> As stated already, it drops packets whilst we don't want that here.
>> 
>> Another difference is that it does vlan_untag(), which we also do
>> not want here.
>> 
>> Let's just stay with this version of the fix, Vlad if you're OK with
>> that can you please give your ACK?  Thanks.
>> 
> 
> 
> Acked-by: Vlad Yasevich <vyasevic at redhat.com>

Applied, thanks everyone.

> I need to spend a little time and figure out how to make it more re-usable.

Ok.


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