ASoC: 88pm860x: array overflow in snd_soc_put_volsw_2r_st()

commit d967967e upstream.

This is called from snd_ctl_elem_write() with user supplied data so we
need to add some bounds checking.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

sound/soc/codecs/88pm860x-codec.c

@@ -351,6 +351,9 @@ static int snd_soc_put_volsw_2r_st(struct snd_kcontrol *kcontrol,
 	val = ucontrol->value.integer.value[0];
 	val2 = ucontrol->value.integer.value[1];
 
+	if (val >= ARRAY_SIZE(st_table) || val2 >= ARRAY_SIZE(st_table))
+		return -EINVAL;
+
 	err = snd_soc_update_bits(codec, reg, 0x3f, st_table[val].m);
 	if (err < 0)
 		return err;