[PATCH v5 1/4] uacce: fix cdev handling in register and remove paths

[Chenghai Huang]

From: Wenkai Lin <linwenkai6@xxxxxxxxxxxxx>

This patch addresses a potential issue in the uacce driver where the
cdev was not properly managed during error handling and cleanup paths.

Changes made:
1. In uacce_register(), store the return value of cdev_device_add()
   and clear the cdev owner as a flag if registration fails.
2. In uacce_remove(), add additional check for cdev owner before
   calling cdev_device_del() to prevent potential issues.

Fixes: 015d239ac014 ("uacce: add uacce driver")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Wenkai Lin <linwenkai6@xxxxxxxxxxxxx>
Signed-off-by: Chenghai Huang <huangchenghai2@xxxxxxxxxx>
---
 drivers/misc/uacce/uacce.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/misc/uacce/uacce.c b/drivers/misc/uacce/uacce.c
index 42e7d2a2a90c..688050c35d88 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 +531,11 @@ 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)
+		uacce->cdev->owner = NULL;
+
+	return ret;
 }
 EXPORT_SYMBOL_GPL(uacce_register);
 
@@ -568,7 +574,7 @@ void uacce_remove(struct uacce_device *uacce)
 		unmap_mapping_range(q->mapping, 0, 0, 1);
 	}
 
-	if (uacce->cdev)
+	if (uacce->cdev && uacce->cdev->owner)
 		cdev_device_del(uacce->cdev, &uacce->dev);
 	xa_erase(&uacce_xa, uacce->dev_id);
 	/*
-- 
2.33.0