• Yunjian Wang's avatar
    net: bridge: Fix ethernet header pointer before check skb forwardable · 28c1382f
    Yunjian Wang authored
    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
    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 packet(Data 1480, UDP 8, IP 20, Ethernet 14, VLAN 4)
    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 doesn't take effect.
    Fixes: f6367b46
     ("bridge: use is_skb_forwardable in forward path")
    Cc: bridge@lists.linux-foundation.org
    Cc: Nkolay Aleksandrov <nikolay@cumulusnetworks.com>
    Cc: Roopa Prabhu <roopa@cumulusnetworks.com>
    Cc: Stephen Hemminger <stephen@networkplumber.org>
    Signed-off-by: default avatarYunjian Wang <wangyunjian@huawei.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>