On Mon, Apr 04, 2022 at 09:44:02PM +0200, Thomas Zimmermann wrote:
> OF framebuffers do not have an underlying device in the Linux
> device hierarchy. Do a regular unregister call instead of hot
> unplugging such a non-existing device. Fixes a NULL dereference.
> An example error message on ppc64le is shown below.
>
<snip>
>
> Tested with 5.17 on qemu ppc64le emulation.
>
> Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
> Fixes: 27599aacbaef ("fbdev: Hot-unplug firmware fb devices on forced removal")
> Reported-by: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx>
> Cc: Zack Rusin <zackr@xxxxxxxxxx>
> Cc: Javier Martinez Canillas <javierm@xxxxxxxxxx>
> Cc: Hans de Goede <hdegoede@xxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx # v5.11+
> Cc: Helge Deller <deller@xxxxxx>
> Cc: Daniel Vetter <daniel.vetter@xxxxxxxx>
> Cc: Sam Ravnborg <sam@xxxxxxxxxxxx>
> Cc: Zheyu Ma <zheyuma97@xxxxxxxxx>
> Cc: Xiyu Yang <xiyuyang19@xxxxxxxxxxxx>
> Cc: Zhen Lei <thunder.leizhen@xxxxxxxxxx>
> Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
> Cc: Alex Deucher <alexander.deucher@xxxxxxx>
> Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
> Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
> Cc: linux-fbdev@xxxxxxxxxxxxxxx
> Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
> Link: https://lore.kernel.org/all/YkHXO6LGHAN0p1pq@debian/ # [1]
> Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
> ---
Tested-by: Sudip Mukherjee <sudip.mukherjee@xxxxxxxxxxxxxxx>
--
Regards
Sudip
