[PATCH] net/mlx5e: TC, release meter if rule offload fails

[Wentao Liang <vulab@iscas.ac.cn>]

mlx5e_tc_rule_offload() adds the flow meter to the attribute and then
adds the offloaded rule. If mlx5_eswitch_add_offloaded_rule() fails, the
meter reference taken by mlx5e_tc_add_flow_meter() is not dropped.

The error propagates to mlx5e_tc_add_fdb_flow() and the flow is freed
without the OFFLOADED flag, so mlx5e_tc_rule_unoffload() and
mlx5e_tc_del_flow_meter() are never called. Release the meter and the
post meter state in the failure path of mlx5e_tc_rule_offload() itself.

Fixes: a8d52b024d6d ("net/mlx5e: TC, Support offloading police action")
Cc: stable@vger.kernel.org
Assisted-by: DeepSeek-V4.1-Flash and OpenAI Codex
Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
---
 drivers/net/ethernet/mellanox/mlx5/core/en_tc.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
index 708b7987ea4c..17bd92529a44 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
@@ -491,6 +491,8 @@ mlx5e_tc_rule_offload(struct mlx5e_priv *priv,
 		      struct mlx5_flow_attr *attr)
 {
 	struct mlx5_eswitch *esw = priv->mdev->priv.eswitch;
+	struct mlx5_flow_handle *rule;
+	bool meter_added = false;
 	int err;
 
 	if (!is_mdev_switchdev_mode(priv->mdev))
@@ -503,9 +505,14 @@ mlx5e_tc_rule_offload(struct mlx5e_priv *priv,
 		err = mlx5e_tc_add_flow_meter(priv, attr);
 		if (err)
 			return ERR_PTR(err);
+		meter_added = true;
 	}
 
-	return mlx5_eswitch_add_offloaded_rule(esw, spec, attr);
+	rule = mlx5_eswitch_add_offloaded_rule(esw, spec, attr);
+	if (IS_ERR(rule) && meter_added)
+		mlx5e_tc_del_flow_meter(esw, attr);
+
+	return rule;
 }
 
 void
-- 
2.34.1