From b3ab668761786f9df9e19dd2805e657af2f19c41 Mon Sep 17 00:00:00 2001
From: Ian Rogers <irogers@google.com>
Date: Wed, 20 May 2026 12:05:31 -0700
Subject: [PATCH] perf kmem: Fix memory leaks on error path and when skipping
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Fix memory leaks on the error paths and skipped sample handling paths
in the perf kmem tool.

Ensure that all allocated GFP flags and thread references are properly freed and
released via thread__put() when skipping samples or encountering parsing failures,
preventing long-term memory usage leaks during large trace analyses.

Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrew Jones <ajones@ventanamicro.com>
Cc: Anup Patel <anup@brainfault.org>
Cc: Athira Rajeev <atrajeev@linux.ibm.com>
Cc: Blake Jones <blakejones@google.com>
Cc: Chen Ni <nichen@iscas.ac.cn>
Cc: Chun-Tse Shao <ctshao@google.com>
Cc: Dapeng Mi <dapeng1.mi@linux.intel.com>
Cc: Derek Foreman <derek.foreman@collabora.com>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Dr. David Alan Gilbert <linux@treblig.org>
Cc: Howard Chu <howardchu95@gmail.com>
Cc: Hrishikesh Suresh <hrishikesh123s@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Krzysztof Łopatowski <krzysztof.m.lopatowski@gmail.com>
Cc: Leo Yan <leo.yan@arm.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <pjw@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quan Zhou <zhouquan@iscas.ac.cn>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Swapnil Sapkal <swapnil.sapkal@amd.com>
Cc: Thomas Falcon <thomas.falcon@intel.com>
Cc: Tianyou Li <tianyou.li@intel.com>
Cc: Yujie Liu <yujie.liu@intel.com>
Cc: tanze <tanze@kylinos.cn>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/builtin-kmem.c | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/tools/perf/builtin-kmem.c b/tools/perf/builtin-kmem.c
index 68a39f56204d..daf2272c7337 100644
--- a/tools/perf/builtin-kmem.c
+++ b/tools/perf/builtin-kmem.c
@@ -783,17 +783,21 @@ static int parse_gfp_flags(struct perf_sample *sample, unsigned int gfp_flags)
 
 			new = realloc(gfps, (nr_gfps + 1) * sizeof(*gfps));
 			if (new == NULL)
-				return -ENOMEM;
+				goto err_out;
 
 			gfps = new;
-			new += nr_gfps++;
+			new += nr_gfps;
 
 			new->flags = gfp_flags;
 			new->human_readable = strdup(str + 10);
+			if (!new->human_readable)
+				goto err_out;
 			new->compact_str = compact_gfp_flags(str + 10);
-			if (!new->human_readable || !new->compact_str)
-				return -ENOMEM;
-
+			if (!new->compact_str) {
+				free(new->human_readable);
+				goto err_out;
+			}
+			nr_gfps++;
 			qsort(gfps, nr_gfps, sizeof(*gfps), gfpcmp);
 		}
 
@@ -802,6 +806,9 @@ static int parse_gfp_flags(struct perf_sample *sample, unsigned int gfp_flags)
 
 	trace_seq_destroy(&seq);
 	return 0;
+err_out:
+	trace_seq_destroy(&seq);
+	return -ENOMEM;
 }
 
 static int evsel__process_page_alloc_event(struct perf_sample *sample)
@@ -971,6 +978,7 @@ static int process_sample_event(const struct perf_tool *tool __maybe_unused,
 	}
 
 	if (perf_kmem__skip_sample(sample)) {
+		thread__put(thread);
 		return 0;
 	}