Once cdev_device_add() failed, we should use put_device() to decrement
reference count for cleanup. Or it could cause memory leak. Although
operations in err_free_ida are similar to the operations in callback
function fsi_slave_release(), put_device() is a correct handling
operation as comments require when cdev_device_add() fails.

As comment of device_add() says, 'if device_add() succeeds, you should
call device_del() when you want to get rid of it. If device_add() has
not succeeded, use only put_device() to drop the reference count'.

Found by code review.

Cc: stable@vger.kernel.org
Fixes: 371975b0b075 ("fsi/core: Fix error paths on CFAM init")
Signed-off-by: Ma Ke <make24@iscas.ac.cn>
---
 drivers/fsi/fsi-core.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c
index c6c115993ebc..444878ab9fb1 100644
--- a/drivers/fsi/fsi-core.c
+++ b/drivers/fsi/fsi-core.c
@@ -1084,7 +1084,8 @@ static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
 	rc = cdev_device_add(&slave->cdev, &slave->dev);
 	if (rc) {
 		dev_err(&slave->dev, "Error %d creating slave device\n", rc);
-		goto err_free_ida;
+		put_device(&slave->dev);
+		return rc;
 	}
 
 	/* Now that we have the cdev registered with the core, any fatal
@@ -1110,8 +1111,6 @@ static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
 
 	return 0;
 
-err_free_ida:
-	fsi_free_minor(slave->dev.devt);
 err_free:
 	of_node_put(slave->dev.of_node);
 	kfree(slave);
-- 
2.17.1

On 10/22/25 4:18 AM, Ma Ke wrote:
> Once cdev_device_add() failed, we should use put_device() to decrement
> reference count for cleanup. Or it could cause memory leak. Although
> operations in err_free_ida are similar to the operations in callback
> function fsi_slave_release(), put_device() is a correct handling
> operation as comments require when cdev_device_add() fails.
>
> As comment of device_add() says, 'if device_add() succeeds, you should
> call device_del() when you want to get rid of it. If device_add() has
> not succeeded, use only put_device() to drop the reference count'.
>
> Found by code review.


Thanks,


Reviewed-by: Eddie James <eajames@linux.ibm.com>

Tested-by: Eddie James <eajames@linux.ibm.com>


>
> Cc: stable@vger.kernel.org
> Fixes: 371975b0b075 ("fsi/core: Fix error paths on CFAM init")
> Signed-off-by: Ma Ke <make24@iscas.ac.cn>
> ---
>   drivers/fsi/fsi-core.c | 5 ++---
>   1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c
> index c6c115993ebc..444878ab9fb1 100644
> --- a/drivers/fsi/fsi-core.c
> +++ b/drivers/fsi/fsi-core.c
> @@ -1084,7 +1084,8 @@ static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
>   	rc = cdev_device_add(&slave->cdev, &slave->dev);
>   	if (rc) {
>   		dev_err(&slave->dev, "Error %d creating slave device\n", rc);
> -		goto err_free_ida;
> +		put_device(&slave->dev);
> +		return rc;
>   	}
>   
>   	/* Now that we have the cdev registered with the core, any fatal
> @@ -1110,8 +1111,6 @@ static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
>   
>   	return 0;
>   
> -err_free_ida:
> -	fsi_free_minor(slave->dev.devt);
>   err_free:
>   	of_node_put(slave->dev.of_node);
>   	kfree(slave);