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>
Wed, 23 Feb 2022 11:03:09 +0000 (12:03 +0100)
commitd006f2fe7d627b3ff3f637cf2fa90d30e05887c9
tree4a55763ae5d9eb98d147c651e958171490c86ed9
parent960c8a55016bece26140eef7a8077e9dc3709098
drm/i915/opregion: check port number bounds for SWSCI display power state

commit ea958422291de248b9e2eaaeea36004e84b64043 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
(cherry picked from commit 24a644ebbfd3b13cda702f98907f9dd123e34bf9)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/gpu/drm/i915/display/intel_opregion.c