[Bridge] [PATCH net v2] net: bridge: Fix ethernet header pointer before check skb forwardable

Sergei Shtylyov sergei.shtylyov at cogentembedded.com
Tue Jan 15 09:21:56 UTC 2019

On 15.01.2019 6:12, wangyunjian wrote:

> From: Yunjian Wang <wangyunjian at huawei.com>
> The skb header should be set to ethernet header before using
> is_skb_forwardable. Because the ethernet header length has been
> considered in is_skb_forwardable(including dev->hard_header_len
> length).
> To reproduce the issue:
> 1, add 2 ports on linux bridge br using following commands:
> $ brctl addbr br
> $ brctl addif br eth0
> $ brctl addif br eth1
> 2, the mtu of eth0 and eth1 is 1500
> 3, send a 1504 packet from eth0 to eth1
> So the expect result is packet larger than 1500 cannot pass through
> eth0 and eth1. But currently, the packet passes through success, it
> means eth1's mtu limit donen't take effect.

    Doesn't. And MTU.

> Fixes: f6367b4660dd ("bridge: use is_skb_forwardable in forward path")
> Cc: bridge at lists.linux-foundation.org
> Cc: Nkolay Aleksandrov <nikolay at cumulusnetworks.com>
> Cc: Roopa Prabhu <roopa at cumulusnetworks.com>
> Signed-off-by: Yunjian Wang <wangyunjian at huawei.com>

MBR, Sergei

More information about the Bridge mailing list