On Mon, Jan 06, 2025 at 03:47:43PM +0800, Ma Ke wrote:
Once device_register() failed, we should call put_device() to decrement reference count for cleanup. Or it could cause memory leak.
device_register() includes device_add(). 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: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Ma Ke make24@iscas.ac.cn
Changes in v2:
- modified the patch as suggestions.
arch/arm/common/locomo.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/arch/arm/common/locomo.c b/arch/arm/common/locomo.c index 309b74783468..9e48cbb2568e 100644 --- a/arch/arm/common/locomo.c +++ b/arch/arm/common/locomo.c @@ -253,6 +253,8 @@ locomo_init_one_child(struct locomo *lchip, struct locomo_dev_info *info) ret = device_register(&dev->dev); if (ret) {
put_device(&dev->dev);return ret;
This makes the code layout quite horrible.
Instead, I suggest:
dev = kzalloc(sizeof(...)... - if (!dev) { - ret = -ENOMEM; - goto out; - } + if (!dev) + return -ENOMEM;
...
ret = device_register(&dev->dev); - if (ret) { - out: - kfree(dev); - } + if (ret) + put_device(&dev->dev);
Thanks.