On Tue, Dec 15, 2015 at 11:29:45AM +0000, Charles Keepax wrote:

> +int wm_adsp_compr_open(struct wm_adsp *dsp, struct snd_compr_stream *stream)
> +{
> +	struct wm_adsp_compr *compr;
> +	int ret = 0;
> +
> +	mutex_lock(&dsp->pwr_lock);
> +
> +	if (wm_adsp_fw[dsp->fw].num_caps == 0) {
> +		adsp_err(dsp, "Firmware does not support compressed API\n");
> +		ret = -ENXIO;
> +		goto out;
> +	}
> +
> +	if (wm_adsp_fw[dsp->fw].compr_direction != stream->direction) {
> +		adsp_err(dsp, "Firmware does not support stream direction\n");
> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
> +	compr = kzalloc(sizeof(*compr), GFP_KERNEL);

You're doing this under lock but not checking for an attempt to allocate
on a DSP already in use.