1 files changed, 36 insertions, 3 deletions

diff --git a/net/dsa/slave.c b/net/dsa/slave.c
index a78b2bba0332..f7f5d126a704 100644
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -1408,16 +1408,49 @@ static int dsa_slave_changeupper(struct net_device *dev,
         return err;
 }
 
+static int dsa_slave_upper_vlan_check(struct net_device *dev,
+                                      struct netdev_notifier_changeupper_info *
+                                      info)
+{
+        struct netlink_ext_ack *ext_ack;
+        struct net_device *slave;
+        struct dsa_port *dp;
+
+        ext_ack = netdev_notifier_info_to_extack(&info->info);
+
+        if (!is_vlan_dev(dev))
+                return NOTIFY_DONE;
+
+        slave = vlan_dev_real_dev(dev);
+        if (!dsa_slave_dev_check(slave))
+                return NOTIFY_DONE;
+
+        dp = dsa_slave_to_port(slave);
+        if (!dp->bridge_dev)
+                return NOTIFY_DONE;
+
+        /* Deny enslaving a VLAN device into a VLAN-aware bridge */
+        if (br_vlan_enabled(dp->bridge_dev) &&
+            netif_is_bridge_master(info->upper_dev) && info->linking) {
+                NL_SET_ERR_MSG_MOD(ext_ack,
+                                   "Cannot enslave VLAN device into VLAN aware bridge");
+                return notifier_from_errno(-EINVAL);
+        }
+
+        return NOTIFY_DONE;
+}
+
 static int dsa_slave_netdevice_event(struct notifier_block *nb,
                                      unsigned long event, void *ptr)
 {
         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 
-        if (!dsa_slave_dev_check(dev))
-                return NOTIFY_DONE;
+        if (event == NETDEV_CHANGEUPPER) {
+                if (!dsa_slave_dev_check(dev))
+                        return dsa_slave_upper_vlan_check(dev, ptr);
 
-        if (event == NETDEV_CHANGEUPPER)
                 return dsa_slave_changeupper(dev, ptr);
+        }
 
         return NOTIFY_DONE;
 }