[dpdk-dev] [PATCH] net/mlx5: fix segfault when create hash rxq of drop

[Xiaoyu Min <jackmin@mellanox.com>]

When to create hrxq for the drop, it could fail on creating qp and
goto the error handle which will release created ind_table by calling drop
release function, which takes rte_ethdev as the only parameter and uses the
priv->drop_queue.hrxq as input to release.

Unfortunately, at this point, the hrxq is not allocated and
priv->drop_queue.hrxq is still NULL, which leads to a segfault.

This patch fixes the above by allocating the hrxq at first place and when
the error happens, hrxq is released as the last one.

This patch also release other allocated resources by the correct order,
which is missing previously.

Fixes: 78be885295b8 ("net/mlx5: handle drop queues as regular queues")
Cc: stable@dpdk.org

Reported-by: Zengmo Gao <gaozengmo@jd.com>
Signed-off-by: Xiaoyu Min <jackmin@mellanox.com>
---
 drivers/net/mlx5/mlx5_rxq.c | 38 +++++++++++++++++++++++--------------
 1 file changed, 24 insertions(+), 14 deletions(-)

diff --git a/drivers/net/mlx5/mlx5_rxq.c b/drivers/net/mlx5/mlx5_rxq.c
index 0db065a22c..f0ab8438d3 100644
--- a/drivers/net/mlx5/mlx5_rxq.c
+++ b/drivers/net/mlx5/mlx5_rxq.c
@@ -2536,17 +2536,27 @@ struct mlx5_hrxq *
 mlx5_hrxq_drop_new(struct rte_eth_dev *dev)
 {
 	struct mlx5_priv *priv = dev->data->dev_private;
-	struct mlx5_ind_table_obj *ind_tbl;
-	struct ibv_qp *qp;
-	struct mlx5_hrxq *hrxq;
+	struct mlx5_ind_table_obj *ind_tbl = NULL;
+	struct ibv_qp *qp = NULL;
+	struct mlx5_hrxq *hrxq = NULL;
 
 	if (priv->drop_queue.hrxq) {
 		rte_atomic32_inc(&priv->drop_queue.hrxq->refcnt);
 		return priv->drop_queue.hrxq;
 	}
+	hrxq = rte_calloc(__func__, 1, sizeof(*hrxq), 0);
+	if (!hrxq) {
+		DRV_LOG(WARNING,
+			"port %u cannot allocate memory for drop queue",
+			dev->data->port_id);
+		rte_errno = ENOMEM;
+		goto error;
+	}
+	priv->drop_queue.hrxq = hrxq;
 	ind_tbl = mlx5_ind_table_obj_drop_new(dev);
 	if (!ind_tbl)
-		return NULL;
+		goto error;
+	hrxq->ind_table = ind_tbl;
 	qp = mlx5_glue->create_qp_ex(priv->sh->ctx,
 		 &(struct ibv_qp_init_attr_ex){
 			.qp_type = IBV_QPT_RAW_PACKET,
@@ -2570,15 +2580,6 @@ mlx5_hrxq_drop_new(struct rte_eth_dev *dev)
 		rte_errno = errno;
 		goto error;
 	}
-	hrxq = rte_calloc(__func__, 1, sizeof(*hrxq), 0);
-	if (!hrxq) {
-		DRV_LOG(WARNING,
-			"port %u cannot allocate memory for drop queue",
-			dev->data->port_id);
-		rte_errno = ENOMEM;
-		goto error;
-	}
-	hrxq->ind_table = ind_tbl;
 	hrxq->qp = qp;
 #ifdef HAVE_IBV_FLOW_DV_SUPPORT
 	hrxq->action = mlx5_glue->dv_create_flow_action_dest_ibv_qp(hrxq->qp);
@@ -2587,12 +2588,21 @@ mlx5_hrxq_drop_new(struct rte_eth_dev *dev)
 		goto error;
 	}
 #endif
-	priv->drop_queue.hrxq = hrxq;
 	rte_atomic32_set(&hrxq->refcnt, 1);
 	return hrxq;
 error:
+#ifdef HAVE_IBV_FLOW_DV_SUPPORT
+	if (hrxq && hrxq->action)
+		mlx5_glue->destroy_flow_action(hrxq->action);
+#endif
+	if (qp)
+		claim_zero(mlx5_glue->destroy_qp(hrxq->qp));
 	if (ind_tbl)
 		mlx5_ind_table_obj_drop_release(dev);
+	if (hrxq) {
+		priv->drop_queue.hrxq = NULL;
+		rte_free(hrxq);
+	}
 	return NULL;
 }
 
-- 
2.23.0