[PATCH 5.10.y 3/3] mlxsw: fix refcount leak in mlxsw_sp_port_lag_join()

[Sasha Levin <sashal@kernel.org>]

From: Wentao Liang <vulab@iscas.ac.cn>

[ Upstream commit 41c8c1d65b32beacd8d916a22457b4f6e47f45af ]

When mlxsw_sp_port_lag_index_get() fails, mlxsw_sp_port_lag_join()
returns an error without releasing the lag reference obtained by
the earlier mlxsw_sp_lag_get().  All other error paths in the
function jump to the cleanup label that ends with
mlxsw_sp_lag_put(), so this is a single missed release.

Fix the leak by replacing the bare 'return err' with a goto to the
existing error cleanup label, which will drop the reference safely.

Cc: stable@vger.kernel.org
Fixes: 0d65fc13042f ("mlxsw: spectrum: Implement LAG port join/leave")
Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260609083709.209743-1-vulab@iscas.ac.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
index a7d2c59690ad90..86b7642f1668e4 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
@@ -3654,7 +3654,7 @@ static int mlxsw_sp_port_lag_join(struct mlxsw_sp_port *mlxsw_sp_port,
 
 	err = mlxsw_sp_port_lag_index_get(mlxsw_sp, lag_id, &port_index);
 	if (err)
-		return err;
+		goto err_lag_uppers_bridge_join;
 
 	err = mlxsw_sp_lag_uppers_bridge_join(mlxsw_sp_port, lag_dev,
 					      extack);
-- 
2.53.0