[PATCH v2 1/2] ASoC: SOF: stream-ipc: Check for cstream nullity in sof_ipc_msg_data()

[Peter Ujfalusi <peter.ujfalusi@xxxxxxxxxxxxxxx>]

The nullity of sps->cstream should be checked similarly as it is done in
sof_set_stream_data_offset() function.
Assuming that it is not NULL if sps->stream is NULL is incorrect and can
lead to NULL pointer dereference.

Fixes: ef8ba9f79953 ("ASoC: SOF: Add support for compress API for stream data/offset")
Cc: stable@xxxxxxxxxxxxxxx
Reported-by: Curtis Malainey <cujomalainey@xxxxxxxxxxxx>
Closes: https://github.com/thesofproject/linux/pull/5214
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@xxxxxxxxxxxxxxx>
Reviewed-by: Daniel Baluta <daniel.baluta@xxxxxxx>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@xxxxxxxxxxxxxxx>
Reviewed-by: Bard Liao <yung-chuan.liao@xxxxxxxxxxxxxxx>
Reviewed-by: Curtis Malainey <cujomalainey@xxxxxxxxxxxx>
---
 sound/soc/sof/stream-ipc.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/sound/soc/sof/stream-ipc.c b/sound/soc/sof/stream-ipc.c
index 794c7bbccbaf..8262443ac89a 100644
--- a/sound/soc/sof/stream-ipc.c
+++ b/sound/soc/sof/stream-ipc.c
@@ -43,7 +43,7 @@ int sof_ipc_msg_data(struct snd_sof_dev *sdev,
 				return -ESTRPIPE;
 
 			posn_offset = stream->posn_offset;
-		} else {
+		} else if (sps->cstream) {
 
 			struct sof_compr_stream *sstream = sps->cstream->runtime->private_data;
 
@@ -51,6 +51,10 @@ int sof_ipc_msg_data(struct snd_sof_dev *sdev,
 				return -ESTRPIPE;
 
 			posn_offset = sstream->posn_offset;
+
+		} else {
+			dev_err(sdev->dev, "%s: No stream opened\n", __func__);
+			return -EINVAL;
 		}
 
 		snd_sof_dsp_mailbox_read(sdev, posn_offset, p, sz);
-- 
2.47.0