[PATCH 4.4 16/78] ALSA: compress: Prevent bypasses of set_params

Greg Kroah-Hartman
2019-08-22T17:49:14Z

[ Upstream commit 26c3f1542f5064310ad26794c09321780d00c57d ]

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@opensource.cirrus.com>
Acked-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 16269e7ff3904..d0a21a5867673 100644
--- a/sound/core/compress_offload.c
+++ b/sound/core/compress_offload.c
@@ -688,9 +688,15 @@ 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);
@@ -739,9 +745,14 @@ 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) {
@@ -778,9 +789,16 @@ 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;
--
2.20.1