net: restore the original spinlock to protect unicast list

There is a path when an assetion in dev_unicast_sync() appears.

igmp6_group_added -> dev_mc_add -> __dev_set_rx_mode ->
-> vlan_dev_set_rx_mode -> dev_unicast_sync

Therefore we cannot protect this list with rtnl. This patch restores the
original protecting this list with spinlock.

Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Tested-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 16 insertions, 9 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 70c27e0c7c32..43e61ba7bd95 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3865,10 +3865,12 @@ int dev_unicast_delete(struct net_device *dev, void *addr)
 
         ASSERT_RTNL();
 
+        netif_addr_lock_bh(dev);
         err = __hw_addr_del(&dev->uc, addr, dev->addr_len,
                             NETDEV_HW_ADDR_T_UNICAST);
         if (!err)
                 __dev_set_rx_mode(dev);
+        netif_addr_unlock_bh(dev);
         return err;
 }
 EXPORT_SYMBOL(dev_unicast_delete);
@@ -3889,10 +3891,12 @@ int dev_unicast_add(struct net_device *dev, void *addr)
 
         ASSERT_RTNL();
 
+        netif_addr_lock_bh(dev);
         err = __hw_addr_add(&dev->uc, addr, dev->addr_len,
                             NETDEV_HW_ADDR_T_UNICAST);
         if (!err)
                 __dev_set_rx_mode(dev);
+        netif_addr_unlock_bh(dev);
         return err;
 }
 EXPORT_SYMBOL(dev_unicast_add);
@@ -3949,7 +3953,8 @@ void __dev_addr_unsync(struct dev_addr_list **to, int *to_count,
  *      @from: source device
  *
  *      Add newly added addresses to the destination device and release
- *      addresses that have no users left.
+ *      addresses that have no users left. The source device must be
+ *      locked by netif_tx_lock_bh.
  *
  *      This function is intended to be called from the dev->set_rx_mode
  *      function of layered software devices.
@@ -3958,14 +3963,14 @@ int dev_unicast_sync(struct net_device *to, struct net_device *from)
 {
         int err = 0;
 
-        ASSERT_RTNL();
-
         if (to->addr_len != from->addr_len)
                 return -EINVAL;
 
+        netif_addr_lock_bh(to);
         err = __hw_addr_sync(&to->uc, &from->uc, to->addr_len);
         if (!err)
                 __dev_set_rx_mode(to);
+        netif_addr_unlock_bh(to);
         return err;
 }
 EXPORT_SYMBOL(dev_unicast_sync);
@@ -3981,28 +3986,30 @@ EXPORT_SYMBOL(dev_unicast_sync);
  */
 void dev_unicast_unsync(struct net_device *to, struct net_device *from)
 {
-        ASSERT_RTNL();
-
         if (to->addr_len != from->addr_len)
                 return;
 
+        netif_addr_lock_bh(from);
+        netif_addr_lock(to);
         __hw_addr_unsync(&to->uc, &from->uc, to->addr_len);
         __dev_set_rx_mode(to);
+        netif_addr_unlock(to);
+        netif_addr_unlock_bh(from);
 }
 EXPORT_SYMBOL(dev_unicast_unsync);
 
 static void dev_unicast_flush(struct net_device *dev)
 {
-        /* rtnl_mutex must be held here */
-
+        netif_addr_lock_bh(dev);
         __hw_addr_flush(&dev->uc);
+        netif_addr_unlock_bh(dev);
 }
 
 static void dev_unicast_init(struct net_device *dev)
 {
-        /* rtnl_mutex must be held here */
-
+        netif_addr_lock_bh(dev);
         __hw_addr_init(&dev->uc);
+        netif_addr_unlock_bh(dev);
 }