Subject: Re: [PATCH net 1/3] net/mlx5e: Add null check for flow namespace in mlx5e_tc_nic_create_miss_table

From: Leon Romanovsky <[email-masked]>
Date: Mon, 30 Mar 2026 19:49:02 +0300

On Thu, Mar 26, 2026 at 09:58:22PM +0100, Oskar Ray-Frayssinet wrote:
> mlx5_get_flow_namespace() can return NULL if the namespace is not
> available. Add a null check to prevent potential null pointer
> dereference when accessing ns->node.

MLX5_FLOW_NAMESPACE_KERNEL and MLX5_FLOW_NAMESPACE_FDB flow namespaces are always available.
The driver and device cannot operate without them.

Thanks

> 
> Signed-off-by: Oskar Ray-Frayssinet <[email-masked]>
> ---
>  drivers/net/ethernet/mellanox/mlx5/core/en_tc.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
> index 1434b65d4746..503c9cc96a02 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
> @@ -5216,6 +5216,10 @@ static int mlx5e_tc_nic_create_miss_table(struct mlx5e_priv *priv)
>  	ft_attr.level = MLX5E_TC_MISS_LEVEL;
>  	ft_attr.prio = 0;
>  	ns = mlx5_get_flow_namespace(priv->mdev, MLX5_FLOW_NAMESPACE_KERNEL);
> +	if (!ns) {
> +		netdev_err(priv->netdev, "failed to get flow namespace\n");
> +		return -EOPNOTSUPP;
> +	}
>  
>  	*ft = mlx5_create_auto_grouped_flow_table(ns, &ft_attr);
>  	if (IS_ERR(*ft)) {
> -- 
> 2.43.0
>