ASoC: Intel: Add NULL checks for the stream pointer

We should not send IPC stream commands to FW when the stream is
NULL, dereference the NULL pointer may also occur without precheck.
Here add NULL pointer checks for these stream APIs.
Signed-off-by: Jie Yang <yang.jie@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/intel/sst-haswell-ipc.c

@@ -1228,6 +1228,11 @@ int sst_hsw_stream_free(struct sst_hsw *hsw, struct sst_hsw_stream *stream)
 	struct sst_dsp *sst = hsw->dsp;
 	unsigned long flags;
 
+	if (!stream) {
+		dev_warn(hsw->dev, "warning: stream is NULL, no stream to free, ignore it.\n");
+		return 0;
+	}
+
 	/* dont free DSP streams that are not commited */
 	if (!stream->commited)
 		goto out;
@@ -1415,6 +1420,16 @@ int sst_hsw_stream_commit(struct sst_hsw *hsw, struct sst_hsw_stream *stream)
 	u32 header;
 	int ret;
 
+	if (!stream) {
+		dev_warn(hsw->dev, "warning: stream is NULL, no stream to commit, ignore it.\n");
+		return 0;
+	}
+
+	if (stream->commited) {
+		dev_warn(hsw->dev, "warning: stream is already committed, ignore it.\n");
+		return 0;
+	}
+
 	trace_ipc_request("stream alloc", stream->host_id);
 
 	header = IPC_GLB_TYPE(IPC_GLB_ALLOCATE_STREAM);
@@ -1519,6 +1534,11 @@ int sst_hsw_stream_pause(struct sst_hsw *hsw, struct sst_hsw_stream *stream,
 {
 	int ret;
 
+	if (!stream) {
+		dev_warn(hsw->dev, "warning: stream is NULL, no stream to pause, ignore it.\n");
+		return 0;
+	}
+
 	trace_ipc_request("stream pause", stream->reply.stream_hw_id);
 
 	ret = sst_hsw_stream_operations(hsw, IPC_STR_PAUSE,
@@ -1535,6 +1555,11 @@ int sst_hsw_stream_resume(struct sst_hsw *hsw, struct sst_hsw_stream *stream,
 {
 	int ret;
 
+	if (!stream) {
+		dev_warn(hsw->dev, "warning: stream is NULL, no stream to resume, ignore it.\n");
+		return 0;
+	}
+
 	trace_ipc_request("stream resume", stream->reply.stream_hw_id);
 
 	ret = sst_hsw_stream_operations(hsw, IPC_STR_RESUME,
@@ -1550,6 +1575,11 @@ int sst_hsw_stream_reset(struct sst_hsw *hsw, struct sst_hsw_stream *stream)
 {
 	int ret, tries = 10;
 
+	if (!stream) {
+		dev_warn(hsw->dev, "warning: stream is NULL, no stream to reset, ignore it.\n");
+		return 0;
+	}
+
 	/* dont reset streams that are not commited */
 	if (!stream->commited)
 		return 0;