From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jay Kamat , Roman Gushchin , "Shuah Khan (Samsung OSG)" , Sasha Levin Subject: [PATCH 4.18 078/135] Fix cg_read_strcmp() Date: Tue, 16 Oct 2018 19:05:08 +0200 Message-Id: <20181016170520.552373329@linuxfoundation.org> In-Reply-To: <20181016170515.447235311@linuxfoundation.org> References: <20181016170515.447235311@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jay Kamat [ Upstream commit 48c2bb0b9cf863e0ed78e269f188ce65b73e0fd1 ] Fix a couple issues with cg_read_strcmp(), to improve correctness of cgroup tests - Fix cg_read_strcmp() always returning 0 for empty "needle" strings. Previously, this function read to a size = 1 buffer when comparing against empty strings, which would lead to cg_read_strcmp() comparing two empty strings. - Fix a memory leak in cg_read_strcmp() Fixes: 84092dbcf901 ("selftests: cgroup: add memory controller self-tests") Signed-off-by: Jay Kamat Acked-by: Roman Gushchin Signed-off-by: Shuah Khan (Samsung OSG) Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- tools/testing/selftests/cgroup/cgroup_util.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) --- a/tools/testing/selftests/cgroup/cgroup_util.c +++ b/tools/testing/selftests/cgroup/cgroup_util.c @@ -89,17 +89,28 @@ int cg_read(const char *cgroup, const ch int cg_read_strcmp(const char *cgroup, const char *control, const char *expected) { - size_t size = strlen(expected) + 1; + size_t size; char *buf; + int ret; + + /* Handle the case of comparing against empty string */ + if (!expected) + size = 32; + else + size = strlen(expected) + 1; buf = malloc(size); if (!buf) return -1; - if (cg_read(cgroup, control, buf, size)) + if (cg_read(cgroup, control, buf, size)) { + free(buf); return -1; + } - return strcmp(expected, buf); + ret = strcmp(expected, buf); + free(buf); + return ret; } int cg_read_strstr(const char *cgroup, const char *control, const char *needle)