Commit af602c7aa5fe for kernel
commit af602c7aa5fedc9be3043244017aef4f26c96b70
Author: Eric Dumazet <edumazet@google.com>
Date: Mon Aug 31 20:30:42 2026 +0000
bonding: do not clear curr_active_slave prematurely when releasing all slaves
When releasing all slaves during bond destruction (all == true),
__bond_release_one() unconditionally clears bond->curr_active_slave to
NULL in every iteration.
If a backup slave is released before the active slave,
bond_alb_deinit_slave() triggers rlb_teach_disabled_mac_on_primary(),
which increments the active slave dev promiscuity counter and sets
bond_info->primary_is_promisc = 1.
Because bond->curr_active_slave was prematurely cleared to NULL when
releasing the backup slave, the subsequent iteration releasing the active
slave evaluates oldcurrent as NULL, so bond_change_active_slave(bond, NULL)
is skipped. Consequently, bond_alb_handle_active_change() is never called
to decrement the promiscuity counter, permanently leaking promiscuous
mode on the physical device after bond teardown.
When oldcurrent == slave, bond_change_active_slave(bond, NULL) already sets
bond->curr_active_slave to NULL. We only need to avoid selecting a new
active slave when all == true. Replace the if (all) branch with
if (!all && oldcurrent == slave).
Fixes: 0896341a44bf ("bonding: fix bond_release_all inconsistencies")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Jay Vosburgh <jv@jvosburgh.net>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20260831203042.164466-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 947d92a669b6..a9bff7663eec 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -2517,9 +2517,7 @@ static int __bond_release_one(struct net_device *bond_dev,
bond_alb_deinit_slave(bond, slave);
}
- if (all) {
- RCU_INIT_POINTER(bond->curr_active_slave, NULL);
- } else if (oldcurrent == slave) {
+ if (!all && oldcurrent == slave) {
/* Note that we hold RTNL over this sequence, so there
* is no concern that another slave add/remove event
* will interfere.