The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From a019abd8022061b917da767cd1a66ed823724eab Mon Sep 17 00:00:00 2001

From: Wolfgang Bumiller w.bumiller@proxmox.com Date: Fri, 2 Jul 2021 14:07:36 +0200 Subject: [PATCH] net: bridge: sync fdb to new unicast-filtering ports

Since commit 2796d0c648c9 ("bridge: Automatically manage port promiscuous mode.") bridges with `vlan_filtering 1` and only 1 auto-port don't set IFF_PROMISC for unicast-filtering-capable ports.

Normally on port changes `br_manage_promisc` is called to update the promisc flags and unicast filters if necessary, but it cannot distinguish between *new* ports and ones losing their promisc flag, and new ports end up not receiving the MAC address list.

Fix this by calling `br_fdb_sync_static` in `br_add_if` after the port promisc flags are updated and the unicast filter was supposed to have been filled.

Fixes: 2796d0c648c9 ("bridge: Automatically manage port promiscuous mode.") Signed-off-by: Wolfgang Bumiller w.bumiller@proxmox.com Acked-by: Nikolay Aleksandrov nikolay@nvidia.com Signed-off-by: David S. Miller davem@davemloft.net

diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c index f7d2f472ae24..6e4a32354a13 100644 --- a/net/bridge/br_if.c +++ b/net/bridge/br_if.c @@ -562,7 +562,7 @@ int br_add_if(struct net_bridge *br, struct net_device *dev, struct net_bridge_port *p; int err = 0; unsigned br_hr, dev_hr; - bool changed_addr; + bool changed_addr, fdb_synced = false;

/* Don't allow bridging non-ethernet like devices. */ if ((dev->flags & IFF_LOOPBACK) || @@ -652,6 +652,19 @@ int br_add_if(struct net_bridge *br, struct net_device *dev, list_add_rcu(&p->list, &br->port_list);

nbp_update_port_count(br); + if (!br_promisc_port(p) && (p->dev->priv_flags & IFF_UNICAST_FLT)) { + /* When updating the port count we also update all ports' + * promiscuous mode. + * A port leaving promiscuous mode normally gets the bridge's + * fdb synced to the unicast filter (if supported), however, + * `br_port_clear_promisc` does not distinguish between + * non-promiscuous ports and *new* ports, so we need to + * sync explicitly here. + */ + fdb_synced = br_fdb_sync_static(br, p) == 0; + if (!fdb_synced) + netdev_err(dev, "failed to sync bridge static fdb addresses to this port\n"); + }

netdev_update_features(br->dev);

@@ -701,6 +714,8 @@ int br_add_if(struct net_bridge *br, struct net_device *dev, return 0;

err7: + if (fdb_synced) + br_fdb_unsync_static(br, p); list_del_rcu(&p->list); br_fdb_delete_by_port(br, p, 0, 1); nbp_update_port_count(br);