net: bridge: br_fdb_external_learn_add(): always set EXT_LEARN

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: 710ae72877 ("net: bridge: Mark FDB entries that were added by user as such")
Signed-off-by: Jonas Gorski <jonas.gorski@bisdn.de>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20240903081958.29951-1-jonas.gorski@bisdn.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Jonas Gorski 2024-09-03 10:19:57 +02:00 committed by Jakub Kicinski
parent 8487b4af59
commit bee2ef946d

View File

@ -1469,12 +1469,10 @@ int br_fdb_external_learn_add(struct net_bridge *br, struct net_bridge_port *p,
modified = true;
}
if (test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags)) {
if (test_and_set_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags)) {
/* Refresh entry */
fdb->used = jiffies;
} else if (!test_bit(BR_FDB_ADDED_BY_USER, &fdb->flags)) {
/* Take over SW learned entry */
set_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags);
} else {
modified = true;
}