Re: [PATCH net] net: bridge: flush FDB again after unregistering the RX handler

[Ido Schimmel]

On Thu, Oct 22, 2026 at 08:26:49AM -0700, Cheng Yongkang wrote:
> del_nbp() flushes the port's FDB entries before it unregisters the RX
> handler.  For a normal port, br_stp_disable_port() has already moved
> the port to BR_STATE_DISABLED, so no frame is learned in between.
> 
> That does not hold for an MRP ring port.  br_set_state() ignores state
> changes while BR_MRP_AWARE_BIT is set, so br_stp_disable_port() leaves
> the port state alone, and br_mrp_port_del() then sets the port to
> BR_STATE_FORWARDING (when the bridge is up) before clearing the bit.

Same root cause as [1] where I suggested moving br_mrp_port_del() before
br_stp_disable_port() so that the port is actually disabled. That would
also fix this issue as the port would be disabled before the
synchronize_net() in nbp_vlan_group_unpublish() and the FDB flush that
follows it. Can you test it with your reproducer?

[1] https://lore.kernel.org/netdev/20261012123051.GA714215@shredder/