rtnetlink: call validate_linkmsg in rtnl_create_link

validate_linkmsg() was introduced by commit 1840bb13 ("[RTNL]:
Validate hardware and broadcast address attribute for RTM_NEWLINK")
to validate tb[IFLA_ADDRESS/BROADCAST] for existing links. The same
check should also be done for newly created links.

This patch adds validate_linkmsg() call in rtnl_create_link(), to
avoid the invalid address set when creating some devices like:

  # ip link add dummy0 type dummy
  # ip link add link dummy0 name mac0 address 01:02 type macsec

Fixes: 0e06877c ("[RTNETLINK]: rtnl_link: allow specifying initial device address")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/core/rtnetlink.c

@@ -3285,6 +3285,7 @@ struct net_device *rtnl_create_link(struct net *net, const char *ifname,
 	struct net_device *dev;
 	unsigned int num_tx_queues = 1;
 	unsigned int num_rx_queues = 1;
+	int err;
 
 	if (tb[IFLA_NUM_TX_QUEUES])
 		num_tx_queues = nla_get_u32(tb[IFLA_NUM_TX_QUEUES]);
@@ -3320,13 +3321,18 @@ struct net_device *rtnl_create_link(struct net *net, const char *ifname,
 	if (!dev)
 		return ERR_PTR(-ENOMEM);
 
+	err = validate_linkmsg(dev, tb, extack);
+	if (err < 0) {
+		free_netdev(dev);
+		return ERR_PTR(err);
+	}
+
 	dev_net_set(dev, net);
 	dev->rtnl_link_ops = ops;
 	dev->rtnl_link_state = RTNL_LINK_INITIALIZING;
 
 	if (tb[IFLA_MTU]) {
 		u32 mtu = nla_get_u32(tb[IFLA_MTU]);
-		int err;
 
 		err = dev_validate_mtu(dev, mtu, extack);
 		if (err) {