drm/amd/display: Check gpio_id before used as array index

[ Upstream commit 2a5626e ] [WHY & HOW] GPIO_ID_UNKNOWN (-1) is not a valid value for array index and therefore should be checked in advance. This fixes 5 OVERRUN issues reported by Coverity. Reviewed-by: Harry Wentland <[email protected]> Acked-by: Tom Chung <[email protected]> Signed-off-by: Alex Hung <[email protected]> Tested-by: Daniel Wheeler <[email protected]> Signed-off-by: Alex Deucher <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
xanmod · Sep 8, 2024 · 08e7755 · 08e7755
1 parent 30e60db
commit 08e7755
Showing 1 changed file with 11 additions and 2 deletions.
diff --git a/drivers/gpu/drm/amd/display/dc/gpio/gpio_service.c b/drivers/gpu/drm/amd/display/dc/gpio/gpio_service.c
@@ -239,6 +239,9 @@ static bool is_pin_busy(
 	enum gpio_id id,
 	uint32_t en)
 {
+	if (id == GPIO_ID_UNKNOWN)
+		return false;
+
 	return service->busyness[id][en];
 }
 
@@ -247,6 +250,9 @@ static void set_pin_busy(
 	enum gpio_id id,
 	uint32_t en)
 {
+	if (id == GPIO_ID_UNKNOWN)
+		return;
+
 	service->busyness[id][en] = true;
 }
 
@@ -255,6 +261,9 @@ static void set_pin_free(
 	enum gpio_id id,
 	uint32_t en)
 {
+	if (id == GPIO_ID_UNKNOWN)
+		return;
+
 	service->busyness[id][en] = false;
 }
 
@@ -263,7 +272,7 @@ enum gpio_result dal_gpio_service_lock(
 	enum gpio_id id,
 	uint32_t en)
 {
-	if (!service->busyness[id]) {
+	if (id != GPIO_ID_UNKNOWN && !service->busyness[id]) {
 		ASSERT_CRITICAL(false);
 		return GPIO_RESULT_OPEN_FAILED;
 	}
@@ -277,7 +286,7 @@ enum gpio_result dal_gpio_service_unlock(
 	enum gpio_id id,
 	uint32_t en)
 {
-	if (!service->busyness[id]) {
+	if (id != GPIO_ID_UNKNOWN && !service->busyness[id]) {
 		ASSERT_CRITICAL(false);
 		return GPIO_RESULT_OPEN_FAILED;
 	}