amt: drop unexpected advertisement message

AMT gateway interface should not receive unexpected advertisement messages.
In order to drop these packets, it should check nonce and amt->status.

Fixes: cbc21dc1cfe9 ("amt: add data plane of amt interface")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/drivers/net/amt.c b/drivers/net/amt.c
index e0743c2..2d007c5 100644 (file)
--- a/drivers/net/amt.c
+++ b/drivers/net/amt.c
@@ -2260,6 +2260,10 @@ static bool amt_advertisement_handler(struct amt_dev *amt, struct sk_buff *skb)
            ipv4_is_zeronet(amta->ip4))
                return true;
 
+       if (amt->status != AMT_STATUS_SENT_DISCOVERY ||
+           amt->nonce != amta->nonce)
+               return true;
+
        amt->remote_ip = amta->ip4;
        netdev_dbg(amt->dev, "advertised remote ip = %pI4\n", &amt->remote_ip);
        mod_delayed_work(amt_wq, &amt->req_wq, 0);
@@ -2975,6 +2979,7 @@ static int amt_dev_open(struct net_device *dev)
 
        amt->req_cnt = 0;
        amt->remote_ip = 0;
+       amt->nonce = 0;
        get_random_bytes(&amt->key, sizeof(siphash_key_t));
 
        amt->status = AMT_STATUS_INIT;