linux-kernel - [PATCH v2] recordmcount: Fix memory leaks in the uwrite function

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Message-Id: <20230425024603.4005251-1-zenghao@kylinos.cn>
Date:   Tue, 25 Apr 2023 10:46:03 +0800
From:   Hao Zeng <zenghao@...inos.cn>
To:     rostedt@...dmis.org
Cc:     chenhuacai@...nel.org, zhangqing@...ngson.cn,
        linux-kernel@...r.kernel.org, Hao Zeng <zenghao@...inos.cn>
Subject: [PATCH v2] recordmcount: Fix memory leaks in the uwrite function

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

Signed-off-by: Hao Zeng <zenghao@...inos.cn>
Suggested-by: Steven Rostedt <rostedt@...dmis.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 const count)
 {
 	size_t cnt = count;
 	off_t idx = 0;
+	void *p = NULL;
 
 	file_updated = 1;
 
@@ -117,7 +118,13 @@ static ssize_t uwrite(void const *const buf, size_t const count)
 		off_t aoffset = (file_ptr + count) - file_end;
 
 		if (aoffset > file_append_size) {
-			file_append = realloc(file_append, aoffset);
+			p = realloc(file_append, aoffset);
+			if (!p) {
+				free(file_append);
+				file_append = NULL;
+			} else {
+				file_append = p;
+			}
 			file_append_size = aoffset;
 		}
 		if (!file_append) {
-- 
2.37.2