fib_frontend: fix possible NULL pointer dereference

The two commits 0115e8e (net: remove delay at device dismantle) and 748e2d9 (net: reinstate rtnl in call_netdevice_notifiers()) silently removed a NULL pointer check for in_dev since Linux 3.7. This patch re-introduces this check as it causes crashing the kernel when setting small mtu values on non-ip capable netdevices. Signed-off-by: Oliver Hartkopp <[email protected]> Acked-by: Eric Dumazet <[email protected]> Signed-off-by: David S. Miller <[email protected]>
Freescale · Jan 24, 2014 · a0065f2 · a0065f2
1 parent 322b1f7
commit a0065f2
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
@@ -1047,6 +1047,8 @@ static int fib_netdev_event(struct notifier_block *this, unsigned long event, vo
 	}
 
 	in_dev = __in_dev_get_rtnl(dev);
+	if (!in_dev)
+		return NOTIFY_DONE;
 
 	switch (event) {
 	case NETDEV_UP: