]> git.baikalelectronics.ru Git - kernel.git/commit
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)
committerJani Nikula <jani.nikula@intel.com>
Fri, 11 Feb 2022 07:54:11 +0000 (09:54 +0200)
commit173f1e73d81b544839f4a0662b5b652ac6a34ad2
treecd8d55ce9c47f9e9eb6a88500d7742a236f11d48
parente588bd7a476ebd6f675d033147846ef5836d3ead
drm/i915/opregion: check port number bounds for SWSCI display power state

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: 8be77bdfd167 ("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
drivers/gpu/drm/i915/display/intel_opregion.c