[PATCH] drm/radeon: implement bounds checking on thermal controller lookup

[alexdeuc...@gmail.com]

From: Alex Deucher <alexander.deuc...@amd.com>

Don't read past the end of the array if we encounter an unknown
thermal controller.

Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
---
 drivers/gpu/drm/radeon/radeon_atombios.c |   11 +++++++++--
 1 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_atombios.c 
b/drivers/gpu/drm/radeon/radeon_atombios.c
index e368b30..01b90b4 100644
--- a/drivers/gpu/drm/radeon/radeon_atombios.c
+++ b/drivers/gpu/drm/radeon/radeon_atombios.c
@@ -2009,7 +2009,8 @@ static int radeon_atombios_parse_power_table_1_3(struct 
radeon_device *rdev)
        power_info = (union power_info *)(mode_info->atom_context->bios + 
data_offset);

        /* add the i2c bus for thermal/fan chip */
-       if (power_info->info.ucOverdriveThermalController > 0) {
+       if ((power_info->info.ucOverdriveThermalController > 0) &&
+           (power_info->info.ucOverdriveThermalController < 
ARRAY_SIZE(thermal_controller_names))) {
                DRM_INFO("Possible %s thermal controller at 0x%02x\n",
                         
thermal_controller_names[power_info->info.ucOverdriveThermalController],
                         power_info->info.ucOverdriveControllerAddress >> 1);
@@ -2213,7 +2214,7 @@ static void 
radeon_atombios_add_pplib_thermal_controller(struct radeon_device *r
                           (controller->ucType ==
                            ATOM_PP_THERMALCONTROLLER_EMC2103_WITH_INTERNAL)) {
                        DRM_INFO("Special thermal controller config\n");
-               } else {
+               } else if (controller->ucType < 
ARRAY_SIZE(pp_lib_thermal_controller_names)) {
                        DRM_INFO("Possible %s thermal controller at 0x%02x %s 
fan control\n",
                                 
pp_lib_thermal_controller_names[controller->ucType],
                                 controller->ucI2cAddress >> 1,
@@ -2228,6 +2229,12 @@ static void 
radeon_atombios_add_pplib_thermal_controller(struct radeon_device *r
                                strlcpy(info.type, name, sizeof(info.type));
                                i2c_new_device(&rdev->pm.i2c_bus->adapter, 
&info);
                        }
+               } else {
+                       DRM_INFO("Unknown thermal controller type %d at 0x%02x 
%s fan control\n",
+                                controller->ucType,
+                                controller->ucI2cAddress >> 1,
+                                (controller->ucFanParameters &
+                                 ATOM_PP_FANPARAMETERS_NOFAN) ? "without" : 
"with");
                }
        }
 }
-- 
1.7.7.5