i40e: fix mac filter delete when setting mac address

[ Upstream commit 158daed16efb1170694e420ae06ba8ba954d82e5 ]

A previous commit moved the ether_addr_copy() in i40e_set_mac() before
the mac filter del/add to avoid a race. However it wasn't taken into
account that this alters the mac address being handed to
i40e_del_mac_filter().

Also changed i40e_add_mac_filter() to operate on netdev->dev_addr,
hopefully that makes the code easier to read.

Fixes: 458867b2ca0c ("i40e: don't remove netdev->dev_addr when syncing uc list")

Signed-off-by: Stefan Assmann <sassmann@kpanic.de>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Acked-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 176c99b8251d895991770531eec321cca33f5118..904b42becd45d228724d1762dc6374154f6e9a13 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -1554,17 +1554,17 @@ static int i40e_set_mac(struct net_device *netdev, void *p)
                netdev_info(netdev, "set new mac address %pM\n", addr->sa_data);
 
        /* Copy the address first, so that we avoid a possible race with
-        * .set_rx_mode(). If we copy after changing the address in the filter
-        * list, we might open ourselves to a narrow race window where
-        * .set_rx_mode could delete our dev_addr filter and prevent traffic
-        * from passing.
+        * .set_rx_mode().
+        * - Remove old address from MAC filter
+        * - Copy new address
+        * - Add new address to MAC filter
         */
-       ether_addr_copy(netdev->dev_addr, addr->sa_data);
-
        spin_lock_bh(&vsi->mac_filter_hash_lock);
        i40e_del_mac_filter(vsi, netdev->dev_addr);
-       i40e_add_mac_filter(vsi, addr->sa_data);
+       ether_addr_copy(netdev->dev_addr, addr->sa_data);
+       i40e_add_mac_filter(vsi, netdev->dev_addr);
        spin_unlock_bh(&vsi->mac_filter_hash_lock);
+
        if (vsi->type == I40E_VSI_MAIN) {
                i40e_status ret;