Re: [PATCH] net/mlx5: Fix memory leak in mlx5_sf_dev_add()

[Paolo Abeni <pabeni@redhat.com>]

On Thu, 2022-05-26 at 16:44 +0800, Jianglei Nie wrote:
> The variable id is allocated by mlx5_adev_idx_alloc(). When some error
> happens, the id should be freed by mlx5_adev_idx_free().But when
> auxiliary_device_add() and xa_insert() fail, the id is not freed,which
> will lead to a potential memory leak.
> 
> We can fix it by calling mlx5_sf_dev_add() when auxiliary_device_add()
> and xa_insert() fail.
> 
> Signed-off-by: Jianglei Nie <niejianglei2021@163.com>
> ---
>  drivers/net/ethernet/mellanox/mlx5/core/sf/dev/dev.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/sf/dev/dev.c b/drivers/net/ethernet/mellanox/mlx5/core/sf/dev/dev.c
> index 7da012ff0d41..9f222061a1c0 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/sf/dev/dev.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/sf/dev/dev.c
> @@ -125,13 +125,16 @@ static void mlx5_sf_dev_add(struct mlx5_core_dev *dev, u16 sf_index, u16 fn_id,
>  
>  	err = auxiliary_device_add(&sf_dev->adev);
>  	if (err) {
> +		mlx5_adev_idx_free(id);
>  		put_device(&sf_dev->adev.dev);

This looks not correct. put_device() -> mlx5_sf_dev_release() -> should
already take care of that.

>  		goto add_err;
>  	}
>  
>  	err = xa_insert(&table->devices, sf_index, sf_dev, GFP_KERNEL);
> -	if (err)
> +	if (err) {
> +		mlx5_adev_idx_free(id);
>  		goto xa_err;
> +	}
>  	return;
>  
>  xa_err: