drm/i915/opregion: check port number bounds for SWSCI display power state
authorJani Nikula <jani.nikula@intel.com>
Thu, 10 Feb 2022 10:36:42 +0000 (12:36 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 8 Apr 2022 12:23:04 +0000 (14:23 +0200)
commitd8b8bd1d03ee7db8e7cb79748a70c2eef4dd706f
tree7072d046ab05d31621d8c894e536817391b47603
parent2b08e0189b027d5d54f2b9bc8224391ca624e0cb
drm/i915/opregion: check port number bounds for SWSCI display power state

commit 24a644ebbfd3b13cda702f98907f9dd123e34bf9 upstream.

The mapping from enum port to whatever port numbering scheme is used by
the SWSCI Display Power State Notification is odd, and the memory of it
has faded. In any case, the parameter only has space for ports numbered
[0..4], and UBSAN reports bit shift beyond it when the platform has port
F or more.

Since the SWSCI functionality is supposed to be obsolete for new
platforms (i.e. ones that might have port F or more), just bail out
early if the mapped and mangled port number is beyond what the Display
Power State Notification can support.

Fixes: 9c4b0a683193 ("drm/i915: add opregion function to notify bios of encoder enable/disable")
Cc: <stable@vger.kernel.org> # v3.13+
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/4800
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/cc363f42d6b5a5932b6d218fefcc8bdfb15dbbe5.1644489329.git.jani.nikula@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/gpu/drm/i915/display/intel_opregion.c