Re: [PATCH net V2] net: bridge: br_fdb_external_learn_add(): always set EXT_LEARN

[Ido Schimmel]

On Tue, Sep 03, 2024 at 10:19:57AM +0200, Jonas Gorski wrote:
> When userspace wants to take over a fdb entry by setting it as
> EXTERN_LEARNED, we set both flags BR_FDB_ADDED_BY_EXT_LEARN and
> BR_FDB_ADDED_BY_USER in br_fdb_external_learn_add().
> 
> If the bridge updates the entry later because its port changed, we clear
> the BR_FDB_ADDED_BY_EXT_LEARN flag, but leave the BR_FDB_ADDED_BY_USER
> flag set.
> 
> If userspace then wants to take over the entry again,
> br_fdb_external_learn_add() sees that BR_FDB_ADDED_BY_USER and skips
> setting the BR_FDB_ADDED_BY_EXT_LEARN flags, thus silently ignores the
> update.
> 
> Fix this by always allowing to set BR_FDB_ADDED_BY_EXT_LEARN regardless
> if this was a user fdb entry or not.
> 
> Fixes: 710ae7287737 ("net: bridge: Mark FDB entries that were added by user as such")
> Signed-off-by: Jonas Gorski <jonas.gorski@xxxxxxxx>

Reviewed-by: Ido Schimmel <idosch@xxxxxxxxxx>