drm/radeon: fix handling of v6 power tables

The code was mis-handling variable sized arrays.

Reported-by: Sylvain BERTRAND <sylware@legeek.net>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

1 files changed, 5 insertions, 6 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_atombios.c b/drivers/gpu/drm/radeon/radeon_atombios.c
index 250db7021198..dea6f63c9724 100644
--- a/drivers/gpu/drm/radeon/radeon_atombios.c
+++ b/drivers/gpu/drm/radeon/radeon_atombios.c
@@ -2518,6 +2518,7 @@ static int radeon_atombios_parse_power_table_6(struct radeon_device *rdev)
         int index = GetIndexIntoMasterTable(DATA, PowerPlayInfo);
         u16 data_offset;
         u8 frev, crev;
+        u8 *power_state_offset;
 
         if (!atom_parse_data_header(mode_info->atom_context, index, NULL,
                                    &frev, &crev, &data_offset))
@@ -2540,11 +2541,11 @@ static int radeon_atombios_parse_power_table_6(struct radeon_device *rdev)
                                        state_array->ucNumEntries, GFP_KERNEL);
         if (!rdev->pm.power_state)
                 return state_index;
+        power_state_offset = (u8 *)state_array->states;
         for (i = 0; i < state_array->ucNumEntries; i++) {
                 mode_index = 0;
-                power_state = (union pplib_power_state *)&state_array->states[i];
-                /* XXX this might be an inagua bug... */
-                non_clock_array_index = i; /* power_state->v2.nonClockInfoIndex */
+                power_state = (union pplib_power_state *)power_state_offset;
+                non_clock_array_index = power_state->v2.nonClockInfoIndex;
                 non_clock_info = (struct _ATOM_PPLIB_NONCLOCK_INFO *)
                         &non_clock_info_array->nonClockInfo[non_clock_array_index];
                 rdev->pm.power_state[i].clock_info = kzalloc(sizeof(struct radeon_pm_clock_info) *
@@ -2556,9 +2557,6 @@ static int radeon_atombios_parse_power_table_6(struct radeon_device *rdev)
                 if (power_state->v2.ucNumDPMLevels) {
                         for (j = 0; j < power_state->v2.ucNumDPMLevels; j++) {
                                 clock_array_index = power_state->v2.clockInfoIndex[j];
-                                /* XXX this might be an inagua bug... */
-                                if (clock_array_index >= clock_info_array->ucNumEntries)
-                                        continue;
                                 clock_info = (union pplib_clock_info *)
                                         &clock_info_array->clockInfo[clock_array_index * clock_info_array->ucEntrySize];
                                 valid = radeon_atombios_parse_pplib_clock_info(rdev,
@@ -2580,6 +2578,7 @@ static int radeon_atombios_parse_power_table_6(struct radeon_device *rdev)
                                                                    non_clock_info);
                         state_index++;
                 }
+                power_state_offset += 2 + power_state->v2.ucNumDPMLevels;
         }
         /* if multiple clock modes, mark the lowest as no display */
         for (i = 0; i < state_index; i++) {