Re: [PATCH] drivers: video: backlight: Fix NULL Pointer Dereference in backlight_device_register()

Daniel Thompson
2025-02-13T21:07:37Z

On Mon, Feb 03, 2025 at 03:21:23PM +0200, Jani Nikula wrote:
> On Thu, 30 Jan 2025, Haoyu Li <lihaoyu499@gmail.com> wrote:
> > In the function "wled_probe", the "wled->name" is dynamically allocated
> > (wled_probe -> wled_configure -> devm_kasprintf), which is possible
> > to be null.
> >
> > In the call trace: wled_probe -> devm_backlight_device_register
> > -> backlight_device_register, this "name" variable is directly
> > dereferenced without checking. We add a null-check statement.
> >
> > Fixes: f86b77583d88 ("backlight: pm8941: Convert to using %pOFn instead of device_node.name")
> > Signed-off-by: Haoyu Li <lihaoyu499@gmail.com>
> > Cc: stable@vger.kernel.org
>
> IMO whoever allocates should be responsible for checking NULL instead of
> passing NULL around and expecting everyone check their input for NULL.

Agreed. This should be fixed in at callsites.

Daniel.