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

[jsarha]

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

The original oss-fuzz report, for those who have access, can be found here: https://issues.oss-fuzz.com/u/1/issues/42537298

[lgirdwood]

@jsarha do we need same for IPC4 ?

[kv2019i]

Proposal in line to manage in comp_reset...

[jsarha]

@jsarha do we need same for IPC4 ?

@lgirdwood , the crash report is from IPC3. I have no idea if the same issue would be possible on IPC4, but if we want to cover IPC4 just to be safe, then that is easy. I'll make the change.

This new implementation that covers also IPC4, looks quite different.

[kv2019i]

Thanks @jsarha ! I think this is better. We have many calls to pipeline_reset() and it's hard to conclude all the places are safe w.r.t. source_comp, so better to check.