[PATCH net V2] net/mlx4: Fix the check in attaching steering rules

[Tariq Toukan <tariqt@mellanox.com>]

From: Talat Batheesh <talatb@mellanox.com>

Our previous patch (cited below) introduced a regression
for RAW Eth QPs.

Fix it by checking if the QP number provided by user-space
exists, hence allowing steering rules to be added for valid
QPs only.

Fixes: 89c557687a32 ("net/mlx4_en: Avoid adding steering rules with ...")
Reported-by: Or Gerlitz <gerlitz.or@gmail.com>
Signed-off-by: Talat Batheesh <talatb@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Acked-by: Or Gerlitz <ogerlitz@mellanox.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
---
v2:
* Removed unnecessary EXPORT_SYMBOL_GPL.

 drivers/net/ethernet/mellanox/mlx4/en_ethtool.c |  3 +--
 drivers/net/ethernet/mellanox/mlx4/qp.c         | 13 +++++++++++++
 include/linux/mlx4/qp.h                         |  1 +
 3 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c b/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c
index ae5fdc2df654..00a7cd3dcc2e 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c
@@ -1562,8 +1562,7 @@ static int mlx4_en_flow_replace(struct net_device *dev,
 		qpn = priv->drop_qp.qpn;
 	else if (cmd->fs.ring_cookie & EN_ETHTOOL_QP_ATTACH) {
 		qpn = cmd->fs.ring_cookie & (EN_ETHTOOL_QP_ATTACH - 1);
-		if (qpn < priv->rss_map.base_qpn ||
-		    qpn >= priv->rss_map.base_qpn + priv->rx_ring_num) {
+		if (!mlx4_qp_lookup(priv->mdev->dev, qpn)) {
 			en_warn(priv, "rxnfc: QP (0x%x) doesn't exist\n", qpn);
 			return -EINVAL;
 		}
diff --git a/drivers/net/ethernet/mellanox/mlx4/qp.c b/drivers/net/ethernet/mellanox/mlx4/qp.c
index 2d6abd4662b1..ad92d2311478 100644
--- a/drivers/net/ethernet/mellanox/mlx4/qp.c
+++ b/drivers/net/ethernet/mellanox/mlx4/qp.c
@@ -384,6 +384,19 @@ static void mlx4_qp_free_icm(struct mlx4_dev *dev, int qpn)
 		__mlx4_qp_free_icm(dev, qpn);
 }
 
+struct mlx4_qp *mlx4_qp_lookup(struct mlx4_dev *dev, u32 qpn)
+{
+	struct mlx4_qp_table *qp_table = &mlx4_priv(dev)->qp_table;
+	struct mlx4_qp *qp;
+
+	spin_lock(&qp_table->lock);
+
+	qp = __mlx4_qp_lookup(dev, qpn);
+
+	spin_unlock(&qp_table->lock);
+	return qp;
+}
+
 int mlx4_qp_alloc(struct mlx4_dev *dev, int qpn, struct mlx4_qp *qp, gfp_t gfp)
 {
 	struct mlx4_priv *priv = mlx4_priv(dev);
diff --git a/include/linux/mlx4/qp.h b/include/linux/mlx4/qp.h
index b4ee8f62ce8d..8e2828d48d7f 100644
--- a/include/linux/mlx4/qp.h
+++ b/include/linux/mlx4/qp.h
@@ -470,6 +470,7 @@ struct mlx4_update_qp_params {
 	u16	rate_val;
 };
 
+struct mlx4_qp *mlx4_qp_lookup(struct mlx4_dev *dev, u32 qpn);
 int mlx4_update_qp(struct mlx4_dev *dev, u32 qpn,
 		   enum mlx4_update_qp_attr attr,
 		   struct mlx4_update_qp_params *params);
-- 
1.8.3.1