Re: [PATCH] kernel/power/energy_model.c: fix memory leak with using debugfs_lookup()

From: Rafael J. Wysocki
Date: Thu Feb 09 2023 - 14:37:27 EST


On Thu, Feb 2, 2023 at 4:15 PM Greg Kroah-Hartman
<gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> When calling debugfs_lookup() the result must have dput() called on it,
> otherwise the memory will leak over time. To make things simpler, just
> call debugfs_lookup_and_remove() instead which handles all of the logic
> at once.
>
> Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
> Cc: Pavel Machek <pavel@xxxxxx>
> Cc: Len Brown <len.brown@xxxxxxxxx>
> Cc: linux-pm@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> ---
> kernel/power/energy_model.c | 5 +----
> 1 file changed, 1 insertion(+), 4 deletions(-)
>
> diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c
> index f82111837b8d..7b44f5b89fa1 100644
> --- a/kernel/power/energy_model.c
> +++ b/kernel/power/energy_model.c
> @@ -87,10 +87,7 @@ static void em_debug_create_pd(struct device *dev)
>
> static void em_debug_remove_pd(struct device *dev)
> {
> - struct dentry *debug_dir;
> -
> - debug_dir = debugfs_lookup(dev_name(dev), rootdir);
> - debugfs_remove_recursive(debug_dir);
> + debugfs_lookup_and_remove(dev_name(dev), rootdir);
> }
>
> static int __init em_debug_init(void)
> --

Applied as 6.3 material, thanks!