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 12:39:58 +0000 (14:39 +0200)
commitb84857c06ef9e72d09fadafdbb3ce9af64af954f
treebf17546bddbfd2108f8ed91483766187ce484188
parent88975951d4e04826c3fd077d9b7eadb21ca37bdb
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