net: macsec: revert the MAC address if mdo_upd_secy fails

Revert the MAC address if mdo_upd_secy fails. Offloaded MACsec device
might be left in an inconsistent state.

Signed-off-by: Radu Pirea (NXP OSS) <radu-nicolae.pirea@oss.nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Author: Radu Pirea (NXP OSS)

drivers/net/macsec.c

@@ -3589,21 +3589,19 @@ static int macsec_set_mac_address(struct net_device *dev, void *p)
 	struct macsec_dev *macsec = macsec_priv(dev);
 	struct net_device *real_dev = macsec->real_dev;
 	struct sockaddr *addr = p;
+	u8  old_addr[ETH_ALEN];
 	int err;
 
 	if (!is_valid_ether_addr(addr->sa_data))
 		return -EADDRNOTAVAIL;
 
-	if (!(dev->flags & IFF_UP))
-		goto out;
-
-	err = dev_uc_add(real_dev, addr->sa_data);
-	if (err < 0)
-		return err;
-
-	dev_uc_del(real_dev, dev->dev_addr);
+	if (dev->flags & IFF_UP) {
+		err = dev_uc_add(real_dev, addr->sa_data);
+		if (err < 0)
+			return err;
+	}
 
-out:
+	ether_addr_copy(old_addr, dev->dev_addr);
 	eth_hw_addr_set(dev, addr->sa_data);
 
 	/* If h/w offloading is available, propagate to the device */
@@ -3612,13 +3610,29 @@ static int macsec_set_mac_address(struct net_device *dev, void *p)
 		struct macsec_context ctx;
 
 		ops = macsec_get_ops(macsec, &ctx);
-		if (ops) {
-			ctx.secy = &macsec->secy;
-			macsec_offload(ops->mdo_upd_secy, &ctx);
+		if (!ops) {
+			err = -EOPNOTSUPP;
+			goto restore_old_addr;
 		}
+
+		ctx.secy = &macsec->secy;
+		err = macsec_offload(ops->mdo_upd_secy, &ctx);
+		if (err)
+			goto restore_old_addr;
 	}
 
+	if (dev->flags & IFF_UP)
+		dev_uc_del(real_dev, old_addr);
+
 	return 0;
+
+restore_old_addr:
+	if (dev->flags & IFF_UP)
+		dev_uc_del(real_dev, addr->sa_data);
+
+	eth_hw_addr_set(dev, old_addr);
+
+	return err;
 }
 
 static int macsec_change_mtu(struct net_device *dev, int new_mtu)