[PATCH 1/2] decnet: add RTNL lock when reading address list

[Stephen Hemminger <shemminger@vyatta.com>]

Add missing locking in the case of auto binding to the
default device. The address list might change while this code is looking
at the list. 

Compile tested only, I am not a decnet user.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>

--- a/net/decnet/dn_dev.c	2009-11-11 09:18:02.935313559 -0800
+++ b/net/decnet/dn_dev.c	2009-11-11 09:22:32.157313924 -0800
@@ -828,13 +828,17 @@ static int dn_dev_get_first(struct net_d
 	struct dn_dev *dn_db = (struct dn_dev *)dev->dn_ptr;
 	struct dn_ifaddr *ifa;
 	int rv = -ENODEV;
+
 	if (dn_db == NULL)
 		goto out;
+
+	rtnl_lock();
 	ifa = dn_db->ifa_list;
 	if (ifa != NULL) {
 		*addr = ifa->ifa_local;
 		rv = 0;
 	}
+	rtnl_unlock();
 out:
 	return rv;
 }