[LLC]: use rcu_dereference on receive handler

The receive hander pointer might be modified during network changes
of protocol. So use rcu_dereference (only matters on alpha).

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/llc/llc_input.c b/net/llc/llc_input.c
index d62e0f9..cb9f7f0 100644 (file)
--- a/net/llc/llc_input.c
+++ b/net/llc/llc_input.c
@@ -142,6 +142,8 @@ int llc_rcv(struct sk_buff *skb, struct net_device *dev,
        struct llc_sap *sap;
        struct llc_pdu_sn *pdu;
        int dest;
+       int (*rcv)(struct sk_buff *, struct net_device *,
+                  struct packet_type *, struct net_device *);
 
        /*
         * When the interface is in promisc. mode, drop all the crap that it
@@ -169,8 +171,9 @@ int llc_rcv(struct sk_buff *skb, struct net_device *dev,
         * First the upper layer protocols that don't need the full
         * LLC functionality
         */
-       if (sap->rcv_func) {
-               sap->rcv_func(skb, dev, pt, orig_dev);
+       rcv = rcu_dereference(sap->rcv_func);
+       if (rcv) {
+               rcv(skb, dev, pt, orig_dev);
                goto out_put;
        }
        dest = llc_pdu_type(skb);