ipv4: arp_notify address list bug

[net-next-2.6.git] / net / ipv4 / devinet.c

diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index e92f1fd28aa5161bc28969ba25b3d9d0bf95418e..5df2f6a0b0f01da83bead89554bb7e7492298646 100644 (file)
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -1077,12 +1077,16 @@ static int inetdev_event(struct notifier_block *this, unsigned long event,
                ip_mc_up(in_dev);
                /* fall through */
        case NETDEV_CHANGEADDR:
-               if (IN_DEV_ARP_NOTIFY(in_dev))
-                       arp_send(ARPOP_REQUEST, ETH_P_ARP,
-                                in_dev->ifa_list->ifa_address,
-                                dev,
-                                in_dev->ifa_list->ifa_address,
-                                NULL, dev->dev_addr, NULL);
+               /* Send gratuitous ARP to notify of link change */
+               if (IN_DEV_ARP_NOTIFY(in_dev)) {
+                       struct in_ifaddr *ifa = in_dev->ifa_list;
+
+                       if (ifa)
+                               arp_send(ARPOP_REQUEST, ETH_P_ARP,
+                                        ifa->ifa_address, dev,
+                                        ifa->ifa_address, NULL,
+                                        dev->dev_addr, NULL);
+               }
                break;
        case NETDEV_DOWN:
                ip_mc_down(in_dev);