drm/fb-helper: set x/yres_virtual in drm_fb_helper_check_var

stable inclusion
from stable-v5.10.180
commit dc110b20f4ce752c232ad710a428dd97cf138338
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8DDFN

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=dc110b20f4ce752c232ad710a428dd97cf138338



--------------------------------

commit 1935f0de upstream.

Drivers are supposed to fix this up if needed if they don't outright
reject it. Uncovered by 6c11df58 ("fbmem: Check virtual screen
sizes in fb_set_var()").

Reported-by:  <syzbot+20dcf81733d43ddff661@syzkaller.appspotmail.com>
Link: https://syzkaller.appspot.com/bug?id=c5faf983bfa4a607de530cd3bb008888bf06cefc


Cc: stable@vger.kernel.org # v5.4+
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Javier Martinez Canillas <javierm@redhat.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230404194038.472803-1-daniel.vetter@ffwll.ch


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: sanglipeng <sanglipeng1@jd.com>