[PATCH 1/3] ASoC: tas2562: Validate values for volume writes

[Mark Brown]

tas2562_volume_control_put() does not do any validation of the control
value written by userspace, it uses it to look up a value in a fixed
size array which can easily be overflowed and then writes whatever value
it gets back to the device.  Add validation that we are loading a value
we have in the array.

Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
 sound/soc/codecs/tas2562.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/sound/soc/codecs/tas2562.c b/sound/soc/codecs/tas2562.c
index 2f7cfc2be970..82bc0078a5c7 100644
--- a/sound/soc/codecs/tas2562.c
+++ b/sound/soc/codecs/tas2562.c
@@ -471,10 +471,14 @@ static int tas2562_volume_control_put(struct snd_kcontrol *kcontrol,
 {
 	struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
 	struct tas2562_data *tas2562 = snd_soc_component_get_drvdata(component);
-	int ret;
+	int ret, index;
 	u32 reg_val;
 
-	reg_val = float_vol_db_lookup[ucontrol->value.integer.value[0]/2];
+	index = ucontrol->value.integer.value[0] / 2;
+	if (index < 0 || index >= ARRAY_SIZE(float_vol_db_lookup))
+		return -EINVAL;
+
+	reg_val = float_vol_db_lookup[index];
 	ret = snd_soc_component_write(component, TAS2562_DVC_CFG4,
 				      (reg_val & 0xff));
 	if (ret)

-- 
2.47.3