[dpdk-stable] [PATCH 18.11] net/mlx5: fix crash on hash Rx queue handling for drop

[Xiaoyu Min]

[ upstream commit 8e2f25cf3c14a9d4c4ee7cf5c6971e9fd5ad64c4 ]

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")

Reported-by: Zengmo Gao <gaozengmo at jd.com>
Signed-off-by: Xiaoyu Min <jackmin at mellanox.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo at mellanox.com>
---
 drivers/net/mlx5/mlx5_rxq.c | 34 ++++++++++++++++++++--------------
 1 file changed, 20 insertions(+), 14 deletions(-)

diff --git a/drivers/net/mlx5/mlx5_rxq.c b/drivers/net/mlx5/mlx5_rxq.c
index f6edb10fed..566fb64fad 100644
--- a/drivers/net/mlx5/mlx5_rxq.c
+++ b/drivers/net/mlx5/mlx5_rxq.c
@@ -2140,17 +2140,27 @@ struct mlx5_hrxq *
 mlx5_hrxq_drop_new(struct rte_eth_dev *dev)
 {
 	struct mlx5_priv *priv = dev->data->dev_private;
-	struct mlx5_ind_table_ibv *ind_tbl;
-	struct ibv_qp *qp;
-	struct mlx5_hrxq *hrxq;
+	struct mlx5_ind_table_ibv *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_ibv_drop_new(dev);
 	if (!ind_tbl)
-		return NULL;
+		goto error;
+	hrxq->ind_table = ind_tbl;
 	qp = mlx5_glue->create_qp_ex(priv->ctx,
 		 &(struct ibv_qp_init_attr_ex){
 			.qp_type = IBV_QPT_RAW_PACKET,
@@ -2174,22 +2184,18 @@ 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;
-	priv->drop_queue.hrxq = hrxq;
 	rte_atomic32_set(&hrxq->refcnt, 1);
 	return hrxq;
 error:
+	if (qp)
+		claim_zero(mlx5_glue->destroy_qp(hrxq->qp));
 	if (ind_tbl)
 		mlx5_ind_table_ibv_drop_release(dev);
+	if (hrxq) {
+		priv->drop_queue.hrxq = NULL;
+		rte_free(hrxq);
+	}
 	return NULL;
 }
 
-- 
2.24.0