[PATCH v4] char: xillybus: Fix error handling in xillybus_init_chrdev()

[Ma Ke]

Use cdev_del() instead of direct kobject_put() when cdev_add() fails.
This aligns with standard kernel practice and maintains consistency
within the driver's own error paths.

Found by code review.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: 8cb5d216ab33 ("char: xillybus: Move class-related functions to new xillybus_class.c")
Signed-off-by: Ma Ke <make24@xxxxxxxxxxx>
---
Changes in v4:
- Apologize, due to the long time that has passed since the last v2 version, I was negligent when submitting v3. I have now corrected it;
Changes in v3:
- modified the patch description, centralized cdev cleanup through standard API and maintained symmetry with driver's existing error handling;
Changes in v2:
- modified the patch as suggestions to avoid UAF.
---
 drivers/char/xillybus/xillybus_class.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/char/xillybus/xillybus_class.c b/drivers/char/xillybus/xillybus_class.c
index c92a628e389e..493bbed918c2 100644
--- a/drivers/char/xillybus/xillybus_class.c
+++ b/drivers/char/xillybus/xillybus_class.c
@@ -103,8 +103,7 @@ int xillybus_init_chrdev(struct device *dev,
 		      unit->num_nodes);
 	if (rc) {
 		dev_err(dev, "Failed to add cdev.\n");
-		/* kobject_put() is normally done by cdev_del() */
-		kobject_put(&unit->cdev->kobj);
+		cdev_del(unit->cdev);
 		goto unregister_chrdev;
 	}
 
-- 
2.25.1