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From:   Hao Zeng <zenghao@kylinos.cn>
To:     rostedt@goodmis.org
Cc:     chenhuacai@kernel.org, zhangqing@loongson.cn,
        linux-kernel@vger.kernel.org, Hao Zeng <zenghao@kylinos.cn>
Subject: [PATCH v2] recordmcount: Fix memory leaks in the uwrite function
Date:   Tue, 25 Apr 2023 10:46:03 +0800
Message-Id: <20230425024603.4005251-1-zenghao@kylinos.cn>
MIME-Version: 1.0
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

Common realloc mistake: 'file_append' nulled but not freed upon failure

Signed-off-by: Hao Zeng <zenghao@kylinos.cn>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
---
 scripts/recordmcount.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/scripts/recordmcount.c b/scripts/recordmcount.c
index e30216525325..efeec898f632 100644
--- a/scripts/recordmcount.c
+++ b/scripts/recordmcount.c
@@ -110,6 +110,7 @@ static ssize_t uwrite(void const *const buf, size_t c=
onst count)
 {
 	size_t cnt =3D count;
 	off_t idx =3D 0;
+	void *p =3D NULL;
=20
 	file_updated =3D 1;
=20
@@ -117,7 +118,13 @@ static ssize_t uwrite(void const *const buf, size_t =
const count)
 		off_t aoffset =3D (file_ptr + count) - file_end;
=20
 		if (aoffset > file_append_size) {
-			file_append =3D realloc(file_append, aoffset);
+			p =3D realloc(file_append, aoffset);
+			if (!p) {
+				free(file_append);
+				file_append =3D NULL;
+			} else {
+				file_append =3D p;
+			}
 			file_append_size =3D aoffset;
 		}
 		if (!file_append) {
--=20
2.37.2