[PATCH 2/2] ASoC: ops: Check bounds for second channel in snd_soc_put_volsw_sx()

[Charles Keepax]

From: Mark Brown <broonie at kernel.org>

The bounds checks in snd_soc_put_volsw_sx() are only being applied to the
first channel, meaning it is possible to write out of bounds values to the
second channel in stereo controls. Add appropriate checks.

Signed-off-by: Mark Brown <broonie at kernel.org>
Signed-off-by: Charles Keepax <ckeepax at opensource.cirrus.com>
---

Slight fixup was made over your original version to make the check of
val2 > max be without the min and mask applied.

Thanks,
Charles

 sound/soc/soc-ops.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/sound/soc/soc-ops.c b/sound/soc/soc-ops.c
index 47691119306fb..55b009d3c6815 100644
--- a/sound/soc/soc-ops.c
+++ b/sound/soc/soc-ops.c
@@ -464,10 +464,15 @@ int snd_soc_put_volsw_sx(struct snd_kcontrol *kcontrol,
 	ret = err;
 
 	if (snd_soc_volsw_is_stereo(mc)) {
-		unsigned int val2;
+		unsigned int val2 = ucontrol->value.integer.value[1];
+
+		if (mc->platform_max && val2 > mc->platform_max)
+			return -EINVAL;
+		if (val2 > max)
+			return -EINVAL;
 
 		val_mask = mask << rshift;
-		val2 = (ucontrol->value.integer.value[1] + min) & mask;
+		val2 = (val2 + min) & mask;
 		val2 = val2 << rshift;
 
 		err = snd_soc_component_update_bits(component, reg2, val_mask,
-- 
2.30.2