[PATCH bpf-next] selftests/bpf: Fix file descriptor leak in load_kallsyms()

From: Yuntao Wang <ytcoode@gmail.com>
To: Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Andrii Nakryiko <andrii@kernel.org>
Cc: Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
	Yonghong Song <yhs@fb.com>,
	John Fastabend <john.fastabend@gmail.com>,
	KP Singh <kpsingh@kernel.org>, Shuah Khan <shuah@kernel.org>,
	netdev@vger.kernel.org, bpf@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org,
	Yuntao Wang <ytcoode@gmail.com>
Subject: [PATCH bpf-next] selftests/bpf: Fix file descriptor leak in load_kallsyms()
Date: Tue,  5 Apr 2022 22:57:11 +0800	[thread overview]
Message-ID: <20220405145711.49543-1-ytcoode@gmail.com> (raw)

Currently, if sym_cnt > 0, it just returns and does not close file, fix it.

Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
---
 tools/testing/selftests/bpf/trace_helpers.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c
index 3d6217e3aff7..9c4be2cdb21a 100644
--- a/tools/testing/selftests/bpf/trace_helpers.c
+++ b/tools/testing/selftests/bpf/trace_helpers.c
@@ -25,15 +25,12 @@ static int ksym_cmp(const void *p1, const void *p2)
 
 int load_kallsyms(void)
 {
-	FILE *f = fopen("/proc/kallsyms", "r");
+	FILE *f;
 	char func[256], buf[256];
 	char symbol;
 	void *addr;
 	int i = 0;
 
-	if (!f)
-		return -ENOENT;
-
 	/*
 	 * This is called/used from multiplace places,
 	 * load symbols just once.
@@ -41,6 +38,10 @@ int load_kallsyms(void)
 	if (sym_cnt)
 		return 0;
 
+	f = fopen("/proc/kallsyms", "r");
+	if (!f)
+		return -ENOENT;
+
 	while (fgets(buf, sizeof(buf), f)) {
 		if (sscanf(buf, "%p %c %s", &addr, &symbol, func) != 3)
 			break;
-- 
2.35.1

