3.13.11.6 -stable review patch. If anyone has any objections, please let me know.
------------------ From: Toshiaki Makita <[email protected]> [ Upstream commit e0d7968ab6c8bce2437b36fa7f04117e333f196d ] 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 <[email protected]> Acked-by: Vlad Yasevich <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Kamal Mostafa <[email protected]> --- net/bridge/br_input.c | 4 ++-- net/bridge/br_private.h | 7 +++++++ net/bridge/br_vlan.c | 28 ++++++++++++++++++++++++++++ 3 files changed, 37 insertions(+), 2 deletions(-) diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c index fa29179..2bc64f8 100644 --- a/net/bridge/br_input.c +++ b/net/bridge/br_input.c @@ -146,8 +146,8 @@ 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); return 0; /* process further */ } diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h index 045d56e..280f601 100644 --- a/net/bridge/br_private.h +++ b/net/bridge/br_private.h @@ -587,6 +587,7 @@ bool br_allowed_ingress(struct net_bridge *br, struct net_port_vlans *v, struct sk_buff *skb, u16 *vid); bool br_allowed_egress(struct net_bridge *br, const struct net_port_vlans *v, const struct sk_buff *skb); +bool br_should_learn(struct net_bridge_port *p, struct sk_buff *skb, u16 *vid); struct sk_buff *br_handle_vlan(struct net_bridge *br, const struct net_port_vlans *v, struct sk_buff *skb); @@ -653,6 +654,12 @@ static inline bool br_allowed_egress(struct net_bridge *br, return true; } +static inline bool br_should_learn(struct net_bridge_port *p, + struct sk_buff *skb, u16 *vid) +{ + return true; +} + static inline struct sk_buff *br_handle_vlan(struct net_bridge *br, const struct net_port_vlans *v, struct sk_buff *skb) diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c index 9bddc9b..4f5341a 100644 --- a/net/bridge/br_vlan.c +++ b/net/bridge/br_vlan.c @@ -252,6 +252,34 @@ bool br_allowed_egress(struct net_bridge *br, return false; } +/* Called under RCU */ +bool br_should_learn(struct net_bridge_port *p, struct sk_buff *skb, u16 *vid) +{ + struct net_bridge *br = p->br; + struct net_port_vlans *v; + + if (!br->vlan_enabled) + return true; + + v = rcu_dereference(p->vlan_info); + if (!v) + return false; + + br_vlan_get_tag(skb, vid); + if (!*vid) { + *vid = br_get_pvid(v); + if (*vid == VLAN_N_VID) + return false; + + return true; + } + + if (test_bit(*vid, v->vlan_bitmap)) + return true; + + return false; +} + /* Must be protected by RTNL. * Must be called with vid in range from 1 to 4094 inclusive. */ -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
