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authorToshiaki Makita <makita.toshiaki@lab.ntt.co.jp>2014-05-26 10:15:53 +0400
committerDavid S. Miller <davem@davemloft.net>2014-06-03 00:38:23 +0400
commite0d7968ab6c8bce2437b36fa7f04117e333f196d (patch)
tree8b066b3ba7134569ba12b5dd21b31be2621adf3c /net/bridge/br_input.c
parentbfc5184b69cf9eeb286137640351c650c27f118a (diff)
downloadlinux-e0d7968ab6c8bce2437b36fa7f04117e333f196d.tar.xz
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.c4
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 */
}