decnet: add RTNL lock when reading address list

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>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/decnet/dn_dev.c b/net/decnet/dn_dev.c
index b5ef237c8a74334c55692f5b535411aa1b580e84..5790d660bc7d8de4997f21beba90344beacfef43 100644 (file)
--- a/net/decnet/dn_dev.c
+++ b/net/decnet/dn_dev.c
@@ -828,13 +828,17 @@ static int dn_dev_get_first(struct net_device *dev, __le16 *addr)
        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;
 }