Re: [PATCH V2] net/mlx5e: fix potential null dereference in mlx5e_tc_nic_create_miss_table

[Tariq Toukan <ttoukan.linux@gmail.com>]

On 07/04/2025 10:20, Charles Han wrote:
> mlx5_get_flow_namespace() may return a NULL pointer, dereferencing it
> without NULL check may lead to NULL dereference.
> Add a NULL check for ns.
> 
> Fixes: 66cb64e292d2 ("net/mlx5e: TC NIC mode, fix tc chains miss table")
> Signed-off-by: Charles Han <hanchunchao@inspur.com>
> ---
>   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 9ba99609999f..c2f23ac95c3d 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->mdev, "Failed to get flow namespace\n");
> +		return -EOPNOTSUPP;
> +	}
>   
>   	*ft = mlx5_create_auto_grouped_flow_table(ns, &ft_attr);
>   	if (IS_ERR(*ft)) {

Same question here, did it fail for you, or just saw it while reading 
the code?