In of_unittest_pci_node_verify(), when the add parameter is false,
device_find_any_child() obtains a reference to a child device. This
function implicitly calls get_device() to increment the device's
reference count before returning the pointer. However, the caller
fails to properly release this reference by calling put_device(),
leading to a device reference count leak. Add put_device() in the else
branch immediately after child_dev is no longer needed.

As the comment of device_find_any_child states: "NOTE: you will need
to drop the reference with put_device() after use".

Found by code review.

Cc: stable@vger.kernel.org
Fixes: 26409dd04589 ("of: unittest: Add pci_dt_testdrv pci driver")
Signed-off-by: Ma Ke <make24@iscas.ac.cn>
---
Changes in v2:
- modified the put_device() location as suggestions.
---
 drivers/of/unittest.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c
index e3503ec20f6c..388e9ec2cccf 100644
--- a/drivers/of/unittest.c
+++ b/drivers/of/unittest.c
@@ -4300,6 +4300,7 @@ static int of_unittest_pci_node_verify(struct pci_dev *pdev, bool add)
 		unittest(!np, "Child device tree node is not removed\n");
 		child_dev = device_find_any_child(&pdev->dev);
 		unittest(!child_dev, "Child device is not removed\n");
+		put_device(child_dev);
 	}
 
 failed:
-- 
2.17.1

On Tue, 30 Sep 2025 16:16:18 +0800, Ma Ke wrote:
> In of_unittest_pci_node_verify(), when the add parameter is false,
> device_find_any_child() obtains a reference to a child device. This
> function implicitly calls get_device() to increment the device's
> reference count before returning the pointer. However, the caller
> fails to properly release this reference by calling put_device(),
> leading to a device reference count leak. Add put_device() in the else
> branch immediately after child_dev is no longer needed.
> 
> As the comment of device_find_any_child states: "NOTE: you will need
> to drop the reference with put_device() after use".
> 
> Found by code review.
> 
> Cc: stable@vger.kernel.org
> Fixes: 26409dd04589 ("of: unittest: Add pci_dt_testdrv pci driver")
> Signed-off-by: Ma Ke <make24@iscas.ac.cn>
> ---
> Changes in v2:
> - modified the put_device() location as suggestions.
> ---
>  drivers/of/unittest.c | 1 +
>  1 file changed, 1 insertion(+)
> 

Applied, thanks!