[PATCH v4 02/19] selftests/resctrl: Don't leak buffer in fill_cache()

From: "Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>
To: linux-kselftest@vger.kernel.org,
	Reinette Chatre <reinette.chatre@intel.com>,
	Shuah Khan <shuah@kernel.org>,
	Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>,
	Fenghua Yu <fenghua.yu@intel.com>,
	Colin Ian King <colin.i.king@gmail.com>,
	linux-kernel@vger.kernel.org
Cc: "Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>
Subject: [PATCH v4 02/19] selftests/resctrl: Don't leak buffer in fill_cache()
Date: Thu, 13 Jul 2023 16:19:15 +0300	[thread overview]
Message-ID: <20230713131932.133258-3-ilpo.jarvinen@linux.intel.com> (raw)
In-Reply-To: <20230713131932.133258-1-ilpo.jarvinen@linux.intel.com>

The error path in fill_cache() does return before the allocated buffer
is freed leaking the buffer.

The leak was introduced when fill_cache_read() started to return errors
in c7b607fa9325 ("selftests/resctrl: Fix null pointer dereference on
open failed"), before that both fill functions always returned 0.

Move free() earlier to prevent the mem leak.

Fixes: c7b607fa9325 ("selftests/resctrl: Fix null pointer dereference on open failed")
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
 tools/testing/selftests/resctrl/fill_buf.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/resctrl/fill_buf.c b/tools/testing/selftests/resctrl/fill_buf.c
index 341cc93ca84c..3b328c844896 100644
--- a/tools/testing/selftests/resctrl/fill_buf.c
+++ b/tools/testing/selftests/resctrl/fill_buf.c
@@ -177,12 +177,13 @@ fill_cache(unsigned long long buf_size, int malloc_and_init, int memflush,
 	else
 		ret = fill_cache_write(start_ptr, end_ptr, resctrl_val);
 
+	free(startptr);
+
 	if (ret) {
 		printf("\n Error in fill cache read/write...\n");
 		return -1;
 	}
 
-	free(startptr);
 
 	return 0;
 }
-- 
2.30.2

