ipv4: arp_notify address list bug
This fixes a bug with arp_notify.
If arp_notify is enabled, kernel will crash if address is changed
and no IP address is assigned.
http://bugzilla.kernel.org/show_bug.cgi?id=14330
Reported-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index e92f1fd..5df2f6a 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -1077,12 +1077,16 @@
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);