mlxsw: thermal: Fix null dereference of NULL temperature parameter

Colin Ian King · davem330 · commit f3b5a8907543 · 2021-06-09T15:39:14.000-07:00
The call to mlxsw_thermal_module_temp_and_thresholds_get passes a NULL pointer for the temperature and this can be dereferenced in this function if the mlxsw_reg_query call fails. The simplist fix is to pass the address of dummy temperature variable instead of a NULL pointer. Addresses-Coverity: ("Explicit null dereferenced") Fixes: 72a64c2 ("mlxsw: thermal: Read module temperature thresholds using MTMP register") Signed-off-by: Colin Ian King <colin.king@canonical.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/mellanox/mlxsw/core_thermal.c b/drivers/net/ethernet/mellanox/mlxsw/core_thermal.c
@@ -742,7 +742,7 @@ mlxsw_thermal_module_init(struct device *dev, struct mlxsw_core *core,
 			  struct mlxsw_thermal *thermal, u8 module)
 {
 	struct mlxsw_thermal_module *module_tz;
-	int crit_temp, emerg_temp;
+	int dummy_temp, crit_temp, emerg_temp;
 	u16 sensor_index;
 
 	sensor_index = MLXSW_REG_MTMP_MODULE_INDEX_MIN + module;
@@ -757,7 +757,7 @@ mlxsw_thermal_module_init(struct device *dev, struct mlxsw_core *core,
 	/* Initialize all trip point. */
 	mlxsw_thermal_module_trips_reset(module_tz);
 	/* Read module temperature and thresholds. */
-	mlxsw_thermal_module_temp_and_thresholds_get(core, sensor_index, NULL,
+	mlxsw_thermal_module_temp_and_thresholds_get(core, sensor_index, &dummy_temp,
 						     &crit_temp, &emerg_temp);
 	/* Update trip point according to the module data. */
 	return mlxsw_thermal_module_trips_update(dev, core, module_tz,
