# \[PATCH\] dmaengine: idxd: Fix error handling in idxd\_wq\_cdev\_dev\_setup()

- Subsystems: DMA GENERIC OFFLOAD ENGINE SUBSYSTEM, INTEL IDXD DRIVER, THE REST
- Maintainers: Vinod Koul, Vinicius Costa Gomes, Linus Torvalds
- Status: LANDED (2227ab4216cd · 2020-02-13 15:07)
- Landed in mainline as 2227ab4216cd on 2020-02-13.
- List: dmaengine
- 3 messages, 3 authors
- Page: https://ratatoskr.run/dmaengine/2020/02/11791109/t

## \[PATCH\] dmaengine: idxd: Fix error handling in idxd\_wq\_cdev\_dev\_setup()

- From: Dan Carpenter \<hidden\>
- Date: 2020-02-05 12:33:03 
- Message: https://ratatoskr.run/dmaengine/2020/02/11791109.md

```text
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 <redacted>
---
 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;
 }
-- 
2.11.0

```

## Re: \[PATCH\] dmaengine: idxd: Fix error handling in idxd\_wq\_cdev\_dev\_setup()

- From: Dave Jiang \<dave.jiang@intel.com\>
- Date: 2020-02-05 16:32:08 
- Message: https://ratatoskr.run/dmaengine/2020/02/11791110.md

```text


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 <redacted>

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

> ---
>   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;
>   }
>
```

## Re: \[PATCH\] dmaengine: idxd: Fix error handling in idxd\_wq\_cdev\_dev\_setup()

- From: Vinod Koul \<vkoul@kernel.org\>
- Date: 2020-02-13 15:07:45 
- Message: https://ratatoskr.run/dmaengine/2020/02/11791118.md

```text
On 05-02-20, 15:32, Dan Carpenter wrote:
> We can't call kfree(dev) after calling device_register(dev).  The "dev"
> pointer has to be freed using put_device().

Applied, thanks

-- 
~Vinod
```