[PATCH v1] rtla: Fix crash due to NULL record dereference

[PATCH v1] rtla: Fix crash due to NULL record dereference

[Costa Shulyupin]

The previous patch introduced a crash by dereferencing record,
which can be NULL.

Add checks to prevent the crash.

Signed-off-by: Costa Shulyupin <costa.shul@redhat.com>
---
 tools/tracing/rtla/src/osnoise_hist.c  | 3 ++-
 tools/tracing/rtla/src/osnoise_top.c   | 3 ++-
 tools/tracing/rtla/src/timerlat_hist.c | 3 ++-
 tools/tracing/rtla/src/timerlat_top.c  | 3 ++-
 4 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/tools/tracing/rtla/src/osnoise_hist.c b/tools/tracing/rtla/src/osnoise_hist.c
index 7c6ef67ef3e6c..f94c7c049406d 100644
--- a/tools/tracing/rtla/src/osnoise_hist.c
+++ b/tools/tracing/rtla/src/osnoise_hist.c
@@ -983,7 +983,8 @@ int osnoise_hist_main(int argc, char *argv[])
 
 	if (osnoise_trace_is_off(tool, record)) {
 		printf("rtla osnoise hit stop tracing\n");
-		save_trace_to_file(record->trace.inst, params->trace_output);
+		if (record)
+			save_trace_to_file(record->trace.inst, params->trace_output);
 	}
 
 out_hist:
diff --git a/tools/tracing/rtla/src/osnoise_top.c b/tools/tracing/rtla/src/osnoise_top.c
index 0eeefbbbf3173..003c0f76b1ada 100644
--- a/tools/tracing/rtla/src/osnoise_top.c
+++ b/tools/tracing/rtla/src/osnoise_top.c
@@ -813,7 +813,8 @@ int osnoise_top_main(int argc, char **argv)
 
 	if (osnoise_trace_is_off(tool, record)) {
 		printf("osnoise hit stop tracing\n");
-		save_trace_to_file(record->trace.inst, params->trace_output);
+		if (record)
+			save_trace_to_file(record->trace.inst, params->trace_output);
 	}
 
 out_top:
diff --git a/tools/tracing/rtla/src/timerlat_hist.c b/tools/tracing/rtla/src/timerlat_hist.c
index 93d0c9e450204..f91efe8804586 100644
--- a/tools/tracing/rtla/src/timerlat_hist.c
+++ b/tools/tracing/rtla/src/timerlat_hist.c
@@ -1473,7 +1473,8 @@ int timerlat_hist_main(int argc, char *argv[])
 		if (!params->no_aa)
 			timerlat_auto_analysis(params->stop_us, params->stop_total_us);
 
-		save_trace_to_file(record->trace.inst, params->trace_output);
+		if (record)
+			save_trace_to_file(record->trace.inst, params->trace_output);
 	}
 
 out_hist:
diff --git a/tools/tracing/rtla/src/timerlat_top.c b/tools/tracing/rtla/src/timerlat_top.c
index 3894ac37d81ca..f082f8b91afef 100644
--- a/tools/tracing/rtla/src/timerlat_top.c
+++ b/tools/tracing/rtla/src/timerlat_top.c
@@ -1295,7 +1295,8 @@ int timerlat_top_main(int argc, char *argv[])
 		if (!params->no_aa)
 			timerlat_auto_analysis(params->stop_us, params->stop_total_us);
 
-		save_trace_to_file(record->trace.inst, params->trace_output);
+		if (record)
+			save_trace_to_file(record->trace.inst, params->trace_output);
 	} else if (params->aa_only) {
 		/*
 		 * If the trace did not stop with --aa-only, at least print the
-- 
2.48.1

Re: [PATCH v1] rtla: Fix crash due to NULL record dereference

[Tomas Glozar]

so 22. 3. 2025 v 19:40 odesílatel Costa Shulyupin
<costa.shul@redhat.com> napsal:
>
> The previous patch introduced a crash by dereferencing record,
> which can be NULL.
>
> Add checks to prevent the crash.
>
> Signed-off-by: Costa Shulyupin <costa.shul@redhat.com>

This is a duplicate of my fix [1]. I added a NULL check inside the
function and made the callers pass NULL if the record instance is not
initialized.

[1] https://lore.kernel.org/linux-trace-kernel/20250313141034.299117-1-tglozar@redhat.com/

Tomas