Re: [PATCH] drivers: base: power: fix memory leak with using debugfs_lookup()

From: Rafael J. Wysocki
Date: Thu Feb 02 2023 - 09:24:08 EST


On Thu, Feb 2, 2023 at 3:15 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: Kevin Hilman <khilman@xxxxxxxxxx>
> Cc: Ulf Hansson <ulf.hansson@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>
> ---
> drivers/base/power/domain.c | 5 +----
> 1 file changed, 1 insertion(+), 4 deletions(-)
>
> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
> index 967bcf9d415e..6097644ebdc5 100644
> --- a/drivers/base/power/domain.c
> +++ b/drivers/base/power/domain.c
> @@ -220,13 +220,10 @@ static void genpd_debug_add(struct generic_pm_domain *genpd);
>
> static void genpd_debug_remove(struct generic_pm_domain *genpd)
> {
> - struct dentry *d;
> -
> if (!genpd_debugfs_dir)
> return;
>
> - d = debugfs_lookup(genpd->name, genpd_debugfs_dir);
> - debugfs_remove(d);
> + debugfs_lookup_and_remove(genpd->name, genpd_debugfs_dir);
> }
>
> static void genpd_update_accounting(struct generic_pm_domain *genpd)
> --

Does this depend on anything in your tree, or can I apply it?