[PATCH] drm/amd/pm: add return check for cast_const_phw_vega10_power_state

[Bob Zhou <bob.zhou@xxxxxxx>]

To avoid null pointer dereference, add return check and handle null pointer.

Signed-off-by: Bob Zhou <bob.zhou@xxxxxxx>
---
 .../drm/amd/pm/powerplay/hwmgr/vega10_hwmgr.c | 28 +++++++++++++------
 1 file changed, 20 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/vega10_hwmgr.c b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/vega10_hwmgr.c
index 6524d99e5cab..53d98d661af2 100644
--- a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/vega10_hwmgr.c
+++ b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/vega10_hwmgr.c
@@ -3436,16 +3436,20 @@ static int vega10_find_dpm_states_clocks_in_dpm_table(struct pp_hwmgr *hwmgr, co
 	struct vega10_hwmgr *data = hwmgr->backend;
 	const struct phm_set_power_state_input *states =
 			(const struct phm_set_power_state_input *)input;
-	const struct vega10_power_state *vega10_ps =
-			cast_const_phw_vega10_power_state(states->pnew_state);
+	const struct vega10_power_state *vega10_ps;
 	struct vega10_single_dpm_table *sclk_table = &(data->dpm_table.gfx_table);
-	uint32_t sclk = vega10_ps->performance_levels
-			[vega10_ps->performance_level_count - 1].gfx_clock;
 	struct vega10_single_dpm_table *mclk_table = &(data->dpm_table.mem_table);
-	uint32_t mclk = vega10_ps->performance_levels
-			[vega10_ps->performance_level_count - 1].mem_clock;
+	uint32_t sclk, mclk;
 	uint32_t i;
 
+	vega10_ps = cast_const_phw_vega10_power_state(states->pnew_state);
+	if (vega10_ps == NULL)
+		return -EINVAL;
+	sclk = vega10_ps->performance_levels
+			[vega10_ps->performance_level_count - 1].gfx_clock;
+	mclk = vega10_ps->performance_levels
+			[vega10_ps->performance_level_count - 1].mem_clock;
+
 	for (i = 0; i < sclk_table->count; i++) {
 		if (sclk == sclk_table->dpm_levels[i].value)
 			break;
@@ -3748,10 +3752,13 @@ static int vega10_generate_dpm_level_enable_mask(
 	struct vega10_hwmgr *data = hwmgr->backend;
 	const struct phm_set_power_state_input *states =
 			(const struct phm_set_power_state_input *)input;
-	const struct vega10_power_state *vega10_ps =
-			cast_const_phw_vega10_power_state(states->pnew_state);
+	const struct vega10_power_state *vega10_ps;
 	int i;
 
+	vega10_ps = cast_const_phw_vega10_power_state(states->pnew_state);
+	if (vega10_ps == NULL)
+		return -EINVAL;
+
 	PP_ASSERT_WITH_CODE(!vega10_trim_dpm_states(hwmgr, vega10_ps),
 			"Attempt to Trim DPM States Failed!",
 			return -1);
@@ -5036,6 +5043,9 @@ static int vega10_check_states_equal(struct pp_hwmgr *hwmgr,
 	vega10_psa = cast_const_phw_vega10_power_state(pstate1);
 	vega10_psb = cast_const_phw_vega10_power_state(pstate2);
 
+	if (vega10_psa == NULL || vega10_psb == NULL)
+		return -EINVAL;
+
 	/* If the two states don't even have the same number of performance levels
 	 * they cannot be the same state.
 	 */
@@ -5672,6 +5682,8 @@ static int vega10_get_performance_level(struct pp_hwmgr *hwmgr, const struct pp_
 		return -EINVAL;
 
 	vega10_ps = cast_const_phw_vega10_power_state(state);
+	if (vega10_ps == NULL)
+		return -EINVAL;
 
 	i = index > vega10_ps->performance_level_count - 1 ?
 			vega10_ps->performance_level_count - 1 : index;
-- 
2.34.1