net/mlx4_en: Avoid adding steering rules with invalid ring

commit 89c55768 upstream.

Inserting steering rules with illegal ring is an invalid operation,
block it.

Fixes: 82067281 ('net/mlx4_en: Manage flow steering rules with ethtool')
Signed-off-by: Talat Batheesh <talatb@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/net/ethernet/mellanox/mlx4/en_ethtool.c

@@ -930,6 +930,11 @@ 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) {
+			en_warn(priv, "rxnfc: QP (0x%x) doesn't exist\n", qpn);
+			return -EINVAL;
+		}
 	} else {
 		if (cmd->fs.ring_cookie >= priv->rx_ring_num) {
 			en_warn(priv, "rxnfc: RX ring (%llu) doesn't exist\n",