[PATCH 5.14 151/151] ionic: dont remove netdev->dev_addr when syncing uc list

Greg Kroah-Hartman
2021-10-18T14:04:07Z

From: Shannon Nelson <snelson@pensando.io>

commit 5c976a56570f29aaf4a2f9a1bf99789c252183c9 upstream.

Bridging, and possibly other upper stack gizmos, adds the
lower device's netdev->dev_addr to its own uc list, and
then requests it be deleted when the upper bridge device is
removed. This delete request also happens with the bridging
vlan_filtering is enabled and then disabled.

Bonding has a similar behavior with the uc list, but since it
also uses set_mac to manage netdev->dev_addr, it doesn't have
the same the failure case.

Because we store our netdev->dev_addr in our uc list, we need
to ignore the delete request from dev_uc_sync so as to not
lose the address and all hope of communicating. Note that
ndo_set_mac_address is expressly changing netdev->dev_addr,
so no limitation is set there.

Fixes: 2a654540be10 ("ionic: Add Rx filter and rx_mode ndo support")
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/ethernet/pensando/ionic/ionic_lif.c | 4 ++++
1 file changed, 4 insertions(+)

--- a/drivers/net/ethernet/pensando/ionic/ionic_lif.c
+++ b/drivers/net/ethernet/pensando/ionic/ionic_lif.c
@@ -1357,6 +1357,10 @@ static int ionic_addr_add(struct net_dev

static int ionic_addr_del(struct net_device *netdev, const u8 *addr)
{
+ /* Don't delete our own address from the uc list */
+ if (ether_addr_equal(addr, netdev->dev_addr))
+ return 0;
+
return ionic_lif_addr(netdev_priv(netdev), addr, DEL_ADDR);
}