commit 3b82a4db upstream.

The memmap options sent to the udl framebuffer driver were not being
checked for all sets of possible crazy values.  Fix this up by properly
bounding the allowed values.
Reported-by: Eyal Itkin <eyalit@checkpoint.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20180321154553.GA18454@kroah.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>