]> 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)
commita0cf5a00f1a1166b68c459afc4b25f2e29299a51
treecd8d55ce9c47f9e9eb6a88500d7742a236f11d48
parent17caf3c1e22f8316ac8bcfe55cbfdb52fe849008
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: 7fe5f2c393e8 ("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