Re: [PATCH] dmaengine: idxd: Fix error handling in idxd_wq_cdev_dev_setup()

[Dave Jiang <dave.jiang@xxxxxxxxx>]

On 2/5/20 5:32 AM, Dan Carpenter wrote:
> We can't call kfree(dev) after calling device_register(dev).  The "dev"
> pointer has to be freed using put_device().
>
> Fixes: 42d279f9137a ("dmaengine: idxd: add char driver to expose submission portal to userland")
> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

Acked-by: Dave Jiang <dave.jiang@xxxxxxxxx>

> ---
>   drivers/dma/idxd/cdev.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/dma/idxd/cdev.c b/drivers/dma/idxd/cdev.c
> index 1d7347825b95..df47be612ebb 100644
> --- a/drivers/dma/idxd/cdev.c
> +++ b/drivers/dma/idxd/cdev.c
> @@ -204,6 +204,7 @@ static int idxd_wq_cdev_dev_setup(struct idxd_wq *wq)
>   	minor = ida_simple_get(&cdev_ctx->minor_ida, 0, MINORMASK, GFP_KERNEL);
>   	if (minor < 0) {
>   		rc = minor;
> +		kfree(dev);
>   		goto ida_err;
>   	}
>   
> @@ -212,7 +213,6 @@ static int idxd_wq_cdev_dev_setup(struct idxd_wq *wq)
>   	rc = device_register(dev);
>   	if (rc < 0) {
>   		dev_err(&idxd->pdev->dev, "device register failed\n");
> -		put_device(dev);
>   		goto dev_reg_err;
>   	}
>   	idxd_cdev->minor = minor;
> @@ -221,8 +221,8 @@ static int idxd_wq_cdev_dev_setup(struct idxd_wq *wq)
>   
>    dev_reg_err:
>   	ida_simple_remove(&cdev_ctx->minor_ida, MINOR(dev->devt));
> +	put_device(dev);
>    ida_err:
> -	kfree(dev);
>   	idxd_cdev->dev = NULL;
>   	return rc;
>   }