Re: [PATCH v1 4/5] dmaengine: idxd: fix memory leak in error handling path of idxd_alloc

[Dave Jiang <dave.jiang@intel.com>]

On 1/10/25 1:22 AM, Shuai Xue wrote:
> Memory allocated for idxd is not freed if an error occurs during
> idxd_alloc(). To fix it, free the allocated memory in the reverse order
> of allocation before exiting the function in case of an error.
> 
> Signed-off-by: Shuai Xue <xueshuai@linux.alibaba.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>

> ---
>  drivers/dma/idxd/init.c | 24 +++++++++++++++---------
>  1 file changed, 15 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
> index 04a7d7706e53..f0e3244d630d 100644
> --- a/drivers/dma/idxd/init.c
> +++ b/drivers/dma/idxd/init.c
> @@ -565,28 +565,34 @@ static struct idxd_device *idxd_alloc(struct pci_dev *pdev, struct idxd_driver_d
>  	idxd_dev_set_type(&idxd->idxd_dev, idxd->data->type);
>  	idxd->id = ida_alloc(&idxd_ida, GFP_KERNEL);
>  	if (idxd->id < 0)
> -		return NULL;
> +		goto err_ida;
>  
>  	idxd->opcap_bmap = bitmap_zalloc_node(IDXD_MAX_OPCAP_BITS, GFP_KERNEL, dev_to_node(dev));
> -	if (!idxd->opcap_bmap) {
> -		ida_free(&idxd_ida, idxd->id);
> -		return NULL;
> -	}
> +	if (!idxd->opcap_bmap)
> +		goto err_opcap;
>  
>  	device_initialize(conf_dev);
>  	conf_dev->parent = dev;
>  	conf_dev->bus = &dsa_bus_type;
>  	conf_dev->type = idxd->data->dev_type;
>  	rc = dev_set_name(conf_dev, "%s%d", idxd->data->name_prefix, idxd->id);
> -	if (rc < 0) {
> -		put_device(conf_dev);
> -		return NULL;
> -	}
> +	if (rc < 0)
> +		goto err_name;
>  
>  	spin_lock_init(&idxd->dev_lock);
>  	spin_lock_init(&idxd->cmd_lock);
>  
>  	return idxd;
> +
> +err_name:
> +	put_device(conf_dev);
> +	bitmap_free(idxd->opcap_bmap);
> +err_opcap:
> +	ida_free(&idxd_ida, idxd->id);
> +err_ida:
> +	kfree(idxd);
> +
> +	return NULL;
>  }
>  
>  static int idxd_enable_system_pasid(struct idxd_device *idxd)