macvlan: Check return of dev_set_allmulti

allmulti might overflow.
Commit: "netdevice: Fix promiscuity and allmulti overflow" in net-next makes
dev_set_promiscuity/allmulti return error number if overflow happened.

Here, we check the positive increment for allmulti to get error return.

Signed-off-by: Wang Chen <wangchen@cn.fujitsu.com>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index c02ceaa4a2164eedae00c666cda6de9d49f0692d..980001c2cf966f0f312d65be4de1fa88897f4f30 100644 (file)
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -189,12 +189,20 @@ static int macvlan_open(struct net_device *dev)
 
        err = dev_unicast_add(lowerdev, dev->dev_addr, ETH_ALEN);
        if (err < 0)
-               return err;
-       if (dev->flags & IFF_ALLMULTI)
-               dev_set_allmulti(lowerdev, 1);
+               goto out;
+       if (dev->flags & IFF_ALLMULTI) {
+               err = dev_set_allmulti(lowerdev, 1);
+               if (err < 0)
+                       goto del_unicast;
+       }
 
        hlist_add_head_rcu(&vlan->hlist, &port->vlan_hash[dev->dev_addr[5]]);
        return 0;
+
+del_unicast:
+       dev_unicast_delete(lowerdev, dev->dev_addr, ETH_ALEN);
+out:
+       return err;
 }
 
 static int macvlan_stop(struct net_device *dev)