[PATCH v8 26/29] perf timechart: Bounds check CPU

[Ian Rogers]

Ensure the CPU is within expected bounds to avoid out of bound memory
accesses in arrays tracking CPU state.

Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
 tools/perf/builtin-timechart.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/tools/perf/builtin-timechart.c b/tools/perf/builtin-timechart.c
index 64f69bd67c6b..0db2a9bd5b91 100644
--- a/tools/perf/builtin-timechart.c
+++ b/tools/perf/builtin-timechart.c
@@ -607,6 +607,10 @@ process_sample_cpu_idle(struct timechart *tchart __maybe_unused,
 	u32 state  = perf_sample__intval(sample, "state");
 	u32 cpu_id = perf_sample__intval(sample, "cpu_id");
 
+	if (cpu_id >= MAX_CPUS) {
+		pr_debug("Out-of-bounds cpu_id %u\n", cpu_id);
+		return -1;
+	}
 	if (state == (u32)PWR_EVENT_EXIT)
 		c_state_end(tchart, cpu_id, sample->time);
 	else
@@ -622,6 +626,10 @@ process_sample_cpu_frequency(struct timechart *tchart,
 	u32 state  = perf_sample__intval(sample, "state");
 	u32 cpu_id = perf_sample__intval(sample, "cpu_id");
 
+	if (cpu_id >= MAX_CPUS) {
+		pr_debug("Out-of-bounds cpu_id %u\n", cpu_id);
+		return -1;
+	}
 	p_state_change(tchart, cpu_id, sample->time, state);
 	return 0;
 }
@@ -662,6 +670,10 @@ process_sample_power_start(struct timechart *tchart __maybe_unused,
 	u64 cpu_id = perf_sample__intval(sample, "cpu_id");
 	u64 value  = perf_sample__intval(sample, "value");
 
+	if (cpu_id >= MAX_CPUS) {
+		pr_debug("Out-of-bounds cpu_id %llu\n", (unsigned long long)cpu_id);
+		return -1;
+	}
 	c_state_start(cpu_id, sample->time, value);
 	return 0;
 }
@@ -683,6 +695,10 @@ process_sample_power_frequency(struct timechart *tchart,
 	u64 cpu_id = perf_sample__intval(sample, "cpu_id");
 	u64 value  = perf_sample__intval(sample, "value");
 
+	if (cpu_id >= MAX_CPUS) {
+		pr_debug("Out-of-bounds cpu_id %llu\n", (unsigned long long)cpu_id);
+		return -1;
+	}
 	p_state_change(tchart, cpu_id, sample->time, value);
 	return 0;
 }
-- 
2.53.0.1213.gd9a14994de-goog