Re: [PATCH] firmware: psci: Fix refcount leak in psci_dt_init

[Gavin Shan <gshan@redhat.com>]

Hi Miaoqian,

On 3/19/25 1:17 AM, Miaoqian Lin wrote:
> Fix a reference counter leak in psci_dt_init() where of_node_put(np) was
> missing after of_find_matching_node_and_match() when np is unavailable.
> 
> Fixes: bff60792f994 ("arm64: psci: factor invocation code to drivers")
> Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
> ---
>   drivers/firmware/psci/psci.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
> 

I'm wandering if the fix tag is correct enough because !of_device_is_available(np)
wasn't added by bff60792f994.

> diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c
> index a1ebbe9b73b1..38ca190d4a22 100644
> --- a/drivers/firmware/psci/psci.c
> +++ b/drivers/firmware/psci/psci.c
> @@ -804,8 +804,10 @@ int __init psci_dt_init(void)
>   
>   	np = of_find_matching_node_and_match(NULL, psci_of_match, &matched_np);
>   
> -	if (!np || !of_device_is_available(np))
> +	if (!np || !of_device_is_available(np)) {
> +		of_node_put(np);
>   		return -ENODEV;
> +	}

The fix looks good to me. The duplicated of_node_put() can be avoided with
a 'out' tag added, something like below.

	if (!np || !of_device_is_available(np)) {
		ret = -ENODEV;
		goto out;
	}

	:

out:
	of_node_put(np);
	return ret;

>   
>   	init_fn = (psci_initcall_t)matched_np->data;
>   	ret = init_fn(np);

Thanks,
Gavin