rtnl: fix msg size calculation in if_nlmsg_size()

[ Upstream commit c57c7a95 ]

Size of the attribute IFLA_PHYS_PORT_NAME was missing.

Fixes: db24a904 ("net: add support for phys_port_name")
CC: David Ahern <dsahern@gmail.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

net/core/rtnetlink.c

@@ -896,7 +896,8 @@ static noinline size_t if_nlmsg_size(const struct net_device *dev,
 	       + rtnl_link_get_size(dev) /* IFLA_LINKINFO */
 	       + rtnl_link_get_af_size(dev) /* IFLA_AF_SPEC */
 	       + nla_total_size(MAX_PHYS_ITEM_ID_LEN) /* IFLA_PHYS_PORT_ID */
-	       + nla_total_size(MAX_PHYS_ITEM_ID_LEN); /* IFLA_PHYS_SWITCH_ID */
+	       + nla_total_size(MAX_PHYS_ITEM_ID_LEN) /* IFLA_PHYS_SWITCH_ID */
+	       + nla_total_size(IFNAMSIZ); /* IFLA_PHYS_PORT_NAME */
 }
 
 static int rtnl_vf_ports_fill(struct sk_buff *skb, struct net_device *dev)