Re: [PATCH v3 1/9] dmaengine: idxd: fix memory leak in error handling path of idxd_setup_wqs

[Fenghua Yu <fenghuay@nvidia.com>]

On 3/8/25 22:20, Shuai Xue wrote:
> Memory allocated for wqs is not freed if an error occurs during
> idxd_setup_wqs(). To fix it, free the allocated memory in the reverse
> order of allocation before exiting the function in case of an error.
>
> Fixes: 7c5dd23e57c1 ("dmaengine: idxd: fix wq conf_dev 'struct device' lifetime")
> Fixes: 700af3a0a26c ("dmaengine: idxd: add 'struct idxd_dev' as wrapper for conf_dev")
> Fixes: de5819b99489 ("dmaengine: idxd: track enabled workqueues in bitmap")
> Fixes: b0325aefd398 ("dmaengine: idxd: add WQ operation cap restriction support")
> Cc: stable@vger.kernel.org
> Signed-off-by: Shuai Xue <xueshuai@linux.alibaba.com>
> Reviewed-by: Dave Jiang <dave.jiang@intel.com>

Reviewed-by: Fenghua Yu <fenghuay@nvidia.com>

Thanks.

-Fenghua

> ---
>   drivers/dma/idxd/init.c | 30 +++++++++++++++++++++---------
>   1 file changed, 21 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
> index b946f78f85e1..8b775c4a43fc 100644
> --- a/drivers/dma/idxd/init.c
> +++ b/drivers/dma/idxd/init.c
> @@ -169,8 +169,8 @@ static int idxd_setup_wqs(struct idxd_device *idxd)
>   
>   	idxd->wq_enable_map = bitmap_zalloc_node(idxd->max_wqs, GFP_KERNEL, dev_to_node(dev));
>   	if (!idxd->wq_enable_map) {
> -		kfree(idxd->wqs);
> -		return -ENOMEM;
> +		rc = -ENOMEM;
> +		goto err_bitmap;
>   	}
>   
>   	for (i = 0; i < idxd->max_wqs; i++) {
> @@ -189,10 +189,8 @@ static int idxd_setup_wqs(struct idxd_device *idxd)
>   		conf_dev->bus = &dsa_bus_type;
>   		conf_dev->type = &idxd_wq_device_type;
>   		rc = dev_set_name(conf_dev, "wq%d.%d", idxd->id, wq->id);
> -		if (rc < 0) {
> -			put_device(conf_dev);
> +		if (rc < 0)
>   			goto err;
> -		}
>   
>   		mutex_init(&wq->wq_lock);
>   		init_waitqueue_head(&wq->err_queue);
> @@ -203,7 +201,6 @@ static int idxd_setup_wqs(struct idxd_device *idxd)
>   		wq->enqcmds_retries = IDXD_ENQCMDS_RETRIES;
>   		wq->wqcfg = kzalloc_node(idxd->wqcfg_size, GFP_KERNEL, dev_to_node(dev));
>   		if (!wq->wqcfg) {
> -			put_device(conf_dev);
>   			rc = -ENOMEM;
>   			goto err;
>   		}
> @@ -211,9 +208,8 @@ static int idxd_setup_wqs(struct idxd_device *idxd)
>   		if (idxd->hw.wq_cap.op_config) {
>   			wq->opcap_bmap = bitmap_zalloc(IDXD_MAX_OPCAP_BITS, GFP_KERNEL);
>   			if (!wq->opcap_bmap) {
> -				put_device(conf_dev);
>   				rc = -ENOMEM;
> -				goto err;
> +				goto err_opcap_bmap;
>   			}
>   			bitmap_copy(wq->opcap_bmap, idxd->opcap_bmap, IDXD_MAX_OPCAP_BITS);
>   		}
> @@ -224,12 +220,28 @@ static int idxd_setup_wqs(struct idxd_device *idxd)
>   
>   	return 0;
>   
> - err:
> +err_opcap_bmap:
> +	kfree(wq->wqcfg);
> +
> +err:
> +	put_device(conf_dev);
> +	kfree(wq);
> +
>   	while (--i >= 0) {
>   		wq = idxd->wqs[i];
> +		if (idxd->hw.wq_cap.op_config)
> +			bitmap_free(wq->opcap_bmap);
> +		kfree(wq->wqcfg);
>   		conf_dev = wq_confdev(wq);
>   		put_device(conf_dev);
> +		kfree(wq);
> +
>   	}
> +	bitmap_free(idxd->wq_enable_map);
> +
> +err_bitmap:
> +	kfree(idxd->wqs);
> +
>   	return rc;
>   }
>