From dcb87c88952046ef43cb5ba3a5b95eb29c362a16 Mon Sep 17 00:00:00 2001 From: Tanushree Shah Date: Thu, 4 Jun 2026 12:25:19 +0530 Subject: [PATCH] perf data convert json: Fix trace_seq memory leak in process_sample_event() Unlike the in-kernel trace_seq which uses a statically allocated buffer, the userspace traceevent library's trace_seq uses a dynamically allocated one. Therefore, every trace_seq_init() call must be paired with a trace_seq_destroy(), otherwise it produces a memory leak. In process_sample_event(), a trace_seq is initialized for each field when formatting tracepoint raw_data, but the matching trace_seq_destroy() is never called, leaking memory for every field of every sample processed. Add the missing trace_seq_destroy() after using the trace_seq buffer to properly free the allocated memory. Detected with Valgrind on a perf.data file with 2,729 tracepoint samples: Before: definitely lost: 55,537,664 bytes in 13,559 blocks After: definitely lost: 0 bytes in 0 blocks Fixes: 9d895e468429 ("perf data: Add tracepoint fields when converting to JSON") Signed-off-by: Tanushree Shah Signed-off-by: Namhyung Kim --- tools/perf/util/data-convert-json.c | 1 + 1 file changed, 1 insertion(+) diff --git a/tools/perf/util/data-convert-json.c b/tools/perf/util/data-convert-json.c index 40412c3dbdb2..40888b7c4467 100644 --- a/tools/perf/util/data-convert-json.c +++ b/tools/perf/util/data-convert-json.c @@ -258,6 +258,7 @@ static int process_sample_event(const struct perf_tool *tool, trace_seq_init(&s); tep_print_field(&s, sample->raw_data, fields[i]); output_json_key_string(out, true, 3, fields[i]->name, s.buffer); + trace_seq_destroy(&s); i++; }