Re: [PATCH 1/3] driver core: generalize driver_override in struct device

[Gui-Dong Han]

On Mon, Mar 2, 2026 at 6:05 PM Danilo Krummrich <dakr@xxxxxxxxxx> wrote:
>
> On Mon Mar 2, 2026 at 9:36 AM CET, Gui-Dong Han wrote:
> > Applying the following diff fixes the KASAN issue. It was just a minor bug.
> >
> > diff --git a/drivers/base/core.c b/drivers/base/core.c
> > index a8cb90577d10..09b98f02f559 100644
> > --- a/drivers/base/core.c
> > +++ b/drivers/base/core.c
> > @@ -2556,6 +2556,7 @@ static void device_release(struct kobject *kobj)
> >         devres_release_all(dev);
> >
> >         kfree(dev->dma_range_map);
> > +       kfree(dev->driver_override.name);
> >
> >         if (dev->release)
> >                 dev->release(dev);
> > @@ -2566,7 +2567,6 @@ static void device_release(struct kobject *kobj)
> >         else
> >                 WARN(1, KERN_ERR "Device '%s' does not have a
> > release() function, it is broken and must be fixed. See
> > Documentation/core-api/kobject.rst.\n",
> >                         dev_name(dev));
> > -       kfree(dev->driver_override.name);
> >         kfree(p);
> >  }
>
> Yes, we must not access dev after the release callbacks has been called; no idea
> how this kfree() ended up below. Thanks for catching!
>
> > With this applied, along with the PCI driver diff from the WIP patch,
> > the issue is resolved. I tested this on PCI and both PoCs no longer
> > trigger KASAN. I also ran with other debug options enabled (lockdep,
> > sleep inside atomic, etc.) and hit no warnings.
> >
> > I was working on a similar patch recently, but your version is better.
> > Not returning the string directly provides better encapsulation and
> > makes the API much harder to misuse.
>
> Ah, right, I remember you mentioned that! If you want I can add your
> Co-developed-by: to this patch to account for your work.

That would be great, yes please. Thank you!

And thanks for all your hard work on this patch series, it's a really
solid improvement.