1 files changed, 22 insertions, 11 deletions

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 279467b74eb7..85bb38cb56fd 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -2567,9 +2567,12 @@ static int packet_release(struct socket *sock)
  *      Attach a packet hook.
  */
 
-static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 protocol)
+static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 proto)
 {
         struct packet_sock *po = pkt_sk(sk);
+        const struct net_device *dev_curr;
+        __be16 proto_curr;
+        bool need_rehook;
 
         if (po->fanout) {
                 if (dev)
@@ -2579,21 +2582,29 @@ static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 protoc
         }
 
         lock_sock(sk);
-
         spin_lock(&po->bind_lock);
-        unregister_prot_hook(sk, true);
 
-        po->num = protocol;
-        po->prot_hook.type = protocol;
-        if (po->prot_hook.dev)
-                dev_put(po->prot_hook.dev);
+        proto_curr = po->prot_hook.type;
+        dev_curr = po->prot_hook.dev;
+
+        need_rehook = proto_curr != proto || dev_curr != dev;
+
+        if (need_rehook) {
+                unregister_prot_hook(sk, true);
 
-        po->prot_hook.dev = dev;
-        po->ifindex = dev ? dev->ifindex : 0;
+                po->num = proto;
+                po->prot_hook.type = proto;
+
+                if (po->prot_hook.dev)
+                        dev_put(po->prot_hook.dev);
 
-        packet_cached_dev_assign(po, dev);
+                po->prot_hook.dev = dev;
+
+                po->ifindex = dev ? dev->ifindex : 0;
+                packet_cached_dev_assign(po, dev);
+        }
 
-        if (protocol == 0)
+        if (proto == 0 || !need_rehook)
                 goto out_unlock;
 
         if (!dev || (dev->flags & IFF_UP)) {