ASoC: ops: Fix bounds check for _sx controls

For _sx controls the semantics of the max field is not the usual one, max is the number of steps rather than the maximum value. This means that our check in snd_soc_put_volsw_sx() needs to just check against the maximum value.

---
 sound/soc/soc-ops.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index e693070f51fe..1ac7e2ce31a1 100644
@@ -435,7 +435,7 @@ int snd_soc_put_volsw_sx(struct snd_kcontrol *kcontrol,
 	val = ucontrol->value.integer.value[0];
 	if (mc->platform_max && val > mc->platform_max)
 		return -EINVAL;
-	if (val > max - min)
+	if (val > max)
 		return -EINVAL;
 	val_mask = mask << shift;
 	val = (val + min) & mask;

2.30.2

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.

---
 sound/soc/soc-ops.c | 6 ++++++
 1 file changed, 6 insertions(+)

index 1ac7e2ce31a1..7cac26a64e0c 100644
@@ -451,6 +451,12 @@ int snd_soc_put_volsw_sx(struct snd_kcontrol *kcontrol,
 
 		val_mask = mask << rshift;
 		val2 = (ucontrol->value.integer.value[1] + min) & mask;
+
+		if (mc->platform_max && val2 > mc->platform_max)
+			return -EINVAL;
+		if (val2 > max)
+			return -EINVAL;
+
 		val2 = val2 << rshift;
 
 		err = snd_soc_component_update_bits(component, reg2, val_mask,

2.30.2

Applied to

https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next

Thanks!

[1/2] ASoC: ops: Fix bounds check for _sx controls

      commit: 698813ba8c580efb356ace8dbf55f61dac6063a8
[2/2] ASoC: ops: Check bounds for second channel in snd_soc_put_volsw_sx()
      commit: 97eea946b93961fffd29448dcda7398d0d51c4b2

All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced.

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Thanks,
Mark