Re: [PATCH 4.9 34/48] ASoC: ops: Reject out of bounds values in snd_soc_put_volsw_sx()

[Pavel Machek]

Hi!

> commit 4f1e50d6a9cf9c1b8c859d449b5031cacfa8404e upstream.
> 
> We don't currently validate that the values being set are within the range
> we advertised to userspace as being valid, do so and reject any values
> that are out of range.

We are getting reports that this commit breaks audio on some
phones... and indeed it looks like "+ min" is missing in first condition:

https://github.com/baunilla/android_kernel_xiaomi_rosy/commit/969b9d366c1e9564e173aea325ec544dcd7804ff

	val = ucontrol->value.integer.value[0];
-	if (mc->platform_max && val > mc->platform_max)
+	if (mc->platform_max && ((int)val + min) > mc->platform_max)
		return -EINVAL;

What needs to be done to get this fixed?

Best regards,
								Pavel

Reported-by: <theflamefire89@xxxxxxxxx>

> Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> Link: https://lore.kernel.org/r/20220124153253.3548853-3-broonie@xxxxxxxxxx
> Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> ---
>  sound/soc/soc-ops.c |    9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
> 
> --- a/sound/soc/soc-ops.c
> +++ b/sound/soc/soc-ops.c
> @@ -441,8 +441,15 @@ int snd_soc_put_volsw_sx(struct snd_kcon
>  	int err = 0;
>  	unsigned int val, val_mask, val2 = 0;
>  
> +	val = ucontrol->value.integer.value[0];
> +	if (mc->platform_max && val > mc->platform_max)
> +		return -EINVAL;
> +	if (val > max - min)
> +		return -EINVAL;
> +	if (val < 0)
> +		return -EINVAL;
>  	val_mask = mask << shift;
> -	val = (ucontrol->value.integer.value[0] + min) & mask;
> +	val = (val + min) & mask;
>  	val = val << shift;
>  
>  	err = snd_soc_component_update_bits(component, reg, val_mask, val);
> 

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