diff options
| author | Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> | 2014-05-26 15:15:53 +0900 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-06-02 13:38:23 -0700 |
| commit | e0d7968ab6c8bce2437b36fa7f04117e333f196d (patch) | |
| tree | 8b066b3ba7134569ba12b5dd21b31be2621adf3c /net/bridge/br_input.c | |
| parent | bfc5184b69cf9eeb286137640351c650c27f118a (diff) | |
| download | linux-e0d7968ab6c8bce2437b36fa7f04117e333f196d.tar.bz2 | |
bridge: Prevent insertion of FDB entry with disallowed vlan
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@lab.ntt.co.jp>
Acked-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/bridge/br_input.c')
| -rw-r--r-- | net/bridge/br_input.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c index 7985deaff52f..04d6348fd530 100644 --- a/net/bridge/br_input.c +++ b/net/bridge/br_input.c @@ -147,8 +147,8 @@ static int br_handle_local_finish(struct sk_buff *skb) struct net_bridge_port *p = br_port_get_rcu(skb->dev); u16 vid = 0; - br_vlan_get_tag(skb, &vid); - if (p->flags & BR_LEARNING) + /* check if vlan is allowed, to avoid spoofing */ + if (p->flags & BR_LEARNING && br_should_learn(p, skb, &vid)) br_fdb_update(p->br, p, eth_hdr(skb)->h_source, vid, false); return 0; /* process further */ } |