pipeline: graph: Check if source_comp is NULL in pipeline_comp_reset()

The fuzzer engine has produced crash caused by NULL pointer read
that originated from ipc3 ipc_stream_pcm_free(). The crash happens
when the pipeline of the found comp_dev does not have a
source_comp and pipeline_reset() is called for it. This commit
adds check to pipeline_comp_test() for this situation and bails
out if it is found.

Here is the call stack from the situation:

    #0 0x81e9317 in dev_comp_pipe_id sof/sof/src/include/sof/audio/component.h:646:25
    #1 0x81e8015 in pipeline_comp_reset sof/sof/src/audio/pipeline/pipeline-graph.c:326:22
    #2 0x81e7d1d in pipeline_reset sof/sof/src/audio/pipeline/pipeline-graph.c:393:8
    #3 0x820d7ea in ipc_stream_pcm_free sof/sof/src/ipc/ipc3/handler.c:398:8
    #4 0x8208969 in ipc_cmd sof/sof/src/ipc/ipc3/handler.c:1689:9
    #5 0x81cbed8 in ipc_platform_do_cmd sof/sof/src/platform/posix/ipc.c:162:2
    #6 0x81d10db in ipc_do_cmd sof/sof/src/ipc/ipc-common.c:330:9
    #7 0x81f87e9 in task_run sof/sof/zephyr/include/rtos/task.h:94:9
    #8 0x81f8308 in edf_work_handler sof/sof/zephyr/edf_schedule.c:31:16
    #9 0x82b4b32 in work_queue_main sof/zephyr/kernel/work.c:668:3
    #10 0x8193ec2 in z_thread_entry sof/zephyr/lib/os/thread_entry.c:36:2
    #11 0x815f639 in __asan::AsanThread::ThreadStart(unsigned long long) /src/llvm-project/compiler-rt/lib/asan/asan_thread.cpp:277:25

Signed-off-by: Jyri Sarha <jyri.sarha@linux.intel.com>

src/audio/pipeline/pipeline-graph.c

@@ -321,13 +321,20 @@ static int pipeline_comp_reset(struct comp_dev *current,
 {
 	struct pipeline *p = ctx->comp_data;
 	struct pipeline *p_current = current->pipeline;
-	int is_single_ppl = comp_is_single_pipeline(current, p->source_comp);
 	int is_same_sched = pipeline_is_same_sched_comp(p_current, p);
+	int is_single_ppl;
 	int err;
 
 	pipe_dbg(p_current, "pipeline_comp_reset(), current->comp.id = 0x%x, dir = %u",
 		 dev_comp_id(current), dir);
 
+	if (!p->source_comp) {
+		pipe_err(p, "pipeline_comp_reset(): source_comp is NULL");
+		return -EINVAL;
+	}
+
+	is_single_ppl = comp_is_single_pipeline(current, p->source_comp);
+
 	/*
 	 * Reset should propagate to the connected pipelines, which need to be
 	 * scheduled together, except for IPC4, where each pipeline receives