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@suse.de Fixes: 27599aacbaef ("fbdev: Hot-unplug firmware fb devices on forced removal") Reported-by: Sudip Mukherjee sudipm.mukherjee@gmail.com Cc: Zack Rusin zackr@vmware.com Cc: Javier Martinez Canillas javierm@redhat.com Cc: Hans de Goede hdegoede@redhat.com Cc: stable@vger.kernel.org # v5.11+ Cc: Helge Deller deller@gmx.de Cc: Daniel Vetter daniel.vetter@ffwll.ch Cc: Sam Ravnborg sam@ravnborg.org Cc: Zheyu Ma zheyuma97@gmail.com Cc: Xiyu Yang xiyuyang19@fudan.edu.cn Cc: Zhen Lei thunder.leizhen@huawei.com Cc: Matthew Wilcox willy@infradead.org Cc: Alex Deucher alexander.deucher@amd.com Cc: Tetsuo Handa penguin-kernel@i-love.sakura.ne.jp Cc: Guenter Roeck linux@roeck-us.net Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Link: https://lore.kernel.org/all/YkHXO6LGHAN0p1pq@debian/ # [1] Reviewed-by: Daniel Vetter daniel.vetter@ffwll.ch
Tested-by: Sudip Mukherjee sudip.mukherjee@codethink.co.uk
-- Regards Sudip