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

[Greg Kroah-Hartman]

On Thu, Feb 02, 2023 at 03:23:46PM +0100, Rafael J. Wysocki wrote:
> 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?

It does not depend on anything in any of my trees, it's made against
Linus's tree right now so please take it through yours.

thanks!

greg k-h