[alsa-devel] [PATCH v2 2/4] ALSA: compress: Prevent bypasses of set_params

[Takashi Iwai]

On Mon, 22 Jul 2019 11:24:34 +0200,
Charles Keepax wrote:
> 
> Currently, whilst in SNDRV_PCM_STATE_OPEN it is possible to call
> snd_compr_stop, snd_compr_drain and snd_compr_partial_drain, which
> allow a transition to SNDRV_PCM_STATE_SETUP. The stream should
> only be able to move to the setup state once it has received a
> SNDRV_COMPRESS_SET_PARAMS ioctl. Fix this issue by not allowing
> those ioctls whilst in the open state.
> 
> Signed-off-by: Charles Keepax <ckeepax at opensource.cirrus.com>

Applied, thanks.


Takashi

> ---
> 
> No changes since v1.
> 
> Thanks,
> Charles
> 
>  sound/core/compress_offload.c | 30 ++++++++++++++++++++++++------
>  1 file changed, 24 insertions(+), 6 deletions(-)
> 
> diff --git a/sound/core/compress_offload.c b/sound/core/compress_offload.c
> index d79aee6b9edd2..40dae723c59db 100644
> --- a/sound/core/compress_offload.c
> +++ b/sound/core/compress_offload.c
> @@ -711,9 +711,15 @@ static int snd_compr_stop(struct snd_compr_stream *stream)
>  {
>  	int retval;
>  
> -	if (stream->runtime->state == SNDRV_PCM_STATE_PREPARED ||
> -			stream->runtime->state == SNDRV_PCM_STATE_SETUP)
> +	switch (stream->runtime->state) {
> +	case SNDRV_PCM_STATE_OPEN:
> +	case SNDRV_PCM_STATE_SETUP:
> +	case SNDRV_PCM_STATE_PREPARED:
>  		return -EPERM;
> +	default:
> +		break;
> +	}
> +
>  	retval = stream->ops->trigger(stream, SNDRV_PCM_TRIGGER_STOP);
>  	if (!retval) {
>  		snd_compr_drain_notify(stream);
> @@ -801,9 +807,14 @@ static int snd_compr_drain(struct snd_compr_stream *stream)
>  {
>  	int retval;
>  
> -	if (stream->runtime->state == SNDRV_PCM_STATE_PREPARED ||
> -			stream->runtime->state == SNDRV_PCM_STATE_SETUP)
> +	switch (stream->runtime->state) {
> +	case SNDRV_PCM_STATE_OPEN:
> +	case SNDRV_PCM_STATE_SETUP:
> +	case SNDRV_PCM_STATE_PREPARED:
>  		return -EPERM;
> +	default:
> +		break;
> +	}
>  
>  	retval = stream->ops->trigger(stream, SND_COMPR_TRIGGER_DRAIN);
>  	if (retval) {
> @@ -840,9 +851,16 @@ static int snd_compr_next_track(struct snd_compr_stream *stream)
>  static int snd_compr_partial_drain(struct snd_compr_stream *stream)
>  {
>  	int retval;
> -	if (stream->runtime->state == SNDRV_PCM_STATE_PREPARED ||
> -			stream->runtime->state == SNDRV_PCM_STATE_SETUP)
> +
> +	switch (stream->runtime->state) {
> +	case SNDRV_PCM_STATE_OPEN:
> +	case SNDRV_PCM_STATE_SETUP:
> +	case SNDRV_PCM_STATE_PREPARED:
>  		return -EPERM;
> +	default:
> +		break;
> +	}
> +
>  	/* stream can be drained only when next track has been signalled */
>  	if (stream->next_track == false)
>  		return -EPERM;
> -- 
> 2.11.0
> 
>