diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 686ef270ecf7..b60a4c9f8f16 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -661,7 +661,7 @@ static int suspend_prepare(struct regulator_dev *rdev, suspend_state_t state)
 static void print_constraints(struct regulator_dev *rdev)
 {
 	struct regulation_constraints *constraints = rdev->constraints;
-	char buf[80];
+	char buf[80] = "";
 	int count = 0;
 	int ret;
 
diff --git a/drivers/regulator/lp3971.c b/drivers/regulator/lp3971.c
index 76d08c282f9c..4f33a0f4a179 100644
--- a/drivers/regulator/lp3971.c
+++ b/drivers/regulator/lp3971.c
@@ -183,7 +183,7 @@ static int lp3971_ldo_set_voltage(struct regulator_dev *dev,
 		if (vol_map[val] >= min_vol)
 			break;
 
-	if (vol_map[val] > max_vol)
+	if (val > LDO_VOL_MAX_IDX || vol_map[val] > max_vol)
 		return -EINVAL;
 
 	return lp3971_set_bits(lp3971, LP3971_LDO_VOL_CONTR_REG(ldo),
@@ -272,7 +272,7 @@ static int lp3971_dcdc_set_voltage(struct regulator_dev *dev,
 		if (vol_map[val] >= min_vol)
 			break;
 
-	if (vol_map[val] > max_vol)
+	if (val > BUCK_TARGET_VOL_MAX_IDX || vol_map[val] > max_vol)
 		return -EINVAL;
 
 	ret = lp3971_set_bits(lp3971, LP3971_BUCK_TARGET_VOL1_REG(buck),