net/mlx5: Fix null-ptr-deref in mlx5_create_{inner_,}ttc_table()

Add NULL check for mlx5_get_flow_namespace() returns in
mlx5_create_inner_ttc_table() and mlx5_create_ttc_table() to prevent
NULL pointer dereference.

Fixes: 137f3d5 ("net/mlx5: Support matching on l4_type for ttc_table")
Signed-off-by: Henry Martin <bsdhenrymartin@gmail.com>
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Link: https://patch.msgid.link/20250418023814.71789-2-bsdhenrymartin@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: Henry Martin

drivers/net/ethernet/mellanox/mlx5/core/lib/fs_ttc.c

@@ -655,6 +655,11 @@ struct mlx5_ttc_table *mlx5_create_inner_ttc_table(struct mlx5_core_dev *dev,
 	}
 
 	ns = mlx5_get_flow_namespace(dev, params->ns_type);
+	if (!ns) {
+		kvfree(ttc);
+		return ERR_PTR(-EOPNOTSUPP);
+	}
+
 	groups = use_l4_type ? &inner_ttc_groups[TTC_GROUPS_USE_L4_TYPE] :
 			       &inner_ttc_groups[TTC_GROUPS_DEFAULT];
 
@@ -728,6 +733,11 @@ struct mlx5_ttc_table *mlx5_create_ttc_table(struct mlx5_core_dev *dev,
 	}
 
 	ns = mlx5_get_flow_namespace(dev, params->ns_type);
+	if (!ns) {
+		kvfree(ttc);
+		return ERR_PTR(-EOPNOTSUPP);
+	}
+
 	groups = use_l4_type ? &ttc_groups[TTC_GROUPS_USE_L4_TYPE] :
 			       &ttc_groups[TTC_GROUPS_DEFAULT];