[PATCH v3 1/4] uacce: fix for cdev memory leak

[Chenghai Huang <huangchenghai2@huawei.com>]

From: Wenkai Lin <linwenkai6@hisilicon.com>

In uacce_register(), if cdev_device_add() fails, we should properly
decrease the reference count of the cdev kobject and set uacce->cdev
to NULL to avoid potential use-after-free or double free issues.

This change adds proper error handling after cdev_device_add() fails,
ensuring that kobject_put() is called and uacce->cdev is cleared.

Fixes: 015d239ac014 ("uacce: add uacce driver")
Cc: stable@vger.kernel.org
Signed-off-by: Wenkai Lin <linwenkai6@hisilicon.com>
Signed-off-by: Chenghai Huang <huangchenghai2@huawei.com>
---
 drivers/misc/uacce/uacce.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/misc/uacce/uacce.c b/drivers/misc/uacce/uacce.c
index 42e7d2a2a90c..9b82a6731832 100644
--- a/drivers/misc/uacce/uacce.c
+++ b/drivers/misc/uacce/uacce.c
@@ -519,6 +519,8 @@ EXPORT_SYMBOL_GPL(uacce_alloc);
  */
 int uacce_register(struct uacce_device *uacce)
 {
+	int ret;
+
 	if (!uacce)
 		return -ENODEV;
 
@@ -529,7 +531,14 @@ int uacce_register(struct uacce_device *uacce)
 	uacce->cdev->ops = &uacce_fops;
 	uacce->cdev->owner = THIS_MODULE;
 
-	return cdev_device_add(uacce->cdev, &uacce->dev);
+	ret = cdev_device_add(uacce->cdev, &uacce->dev);
+	if (ret) {
+		kobject_put(&uacce->cdev->kobj);
+		uacce->cdev = NULL;
+		return ret;
+	}
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(uacce_register);
 
-- 
2.33.0