[PATCH AUTOSEL 5.4 045/187] selftests: safesetid: Check the return value of setuid/setgid

Sasha Levin
2019-12-27T17:56:56Z

[ Upstream commit 295c4e21cf27ac9af542140e3e797df9e0cf7b5f ]

Check the return value of setuid() and setgid().
This fixes the following warnings and improves test result.

safesetid-test.c: In function ‘main’:
safesetid-test.c:294:2: warning: ignoring return value of ‘setuid’, declared with attribute warn_unused_result [-Wunused-result]
setuid(NO_POLICY_USER);
^~~~~~~~~~~~~~~~~~~~~~
safesetid-test.c:295:2: warning: ignoring return value of ‘setgid’, declared with attribute warn_unused_result [-Wunused-result]
setgid(NO_POLICY_USER);
^~~~~~~~~~~~~~~~~~~~~~
safesetid-test.c:309:2: warning: ignoring return value of ‘setuid’, declared with attribute warn_unused_result [-Wunused-result]
setuid(RESTRICTED_PARENT);
^~~~~~~~~~~~~~~~~~~~~~~~~
safesetid-test.c:310:2: warning: ignoring return value of ‘setgid’, declared with attribute warn_unused_result [-Wunused-result]
setgid(RESTRICTED_PARENT);
^~~~~~~~~~~~~~~~~~~~~~~~~
safesetid-test.c: In function ‘test_setuid’:
safesetid-test.c:216:3: warning: ignoring return value of ‘setuid’, declared with attribute warn_unused_result [-Wunused-result]
setuid(child_uid);
^~~~~~~~~~~~~~~~~

Fixes: c67e8ec03f3f ("LSM: SafeSetID: add selftest")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../testing/selftests/safesetid/safesetid-test.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/tools/testing/selftests/safesetid/safesetid-test.c b/tools/testing/selftests/safesetid/safesetid-test.c
index 8f40c6ecdad1..0c4d50644c13 100644
--- a/tools/testing/selftests/safesetid/safesetid-test.c
+++ b/tools/testing/selftests/safesetid/safesetid-test.c
@@ -213,7 +213,8 @@ static void test_setuid(uid_t child_uid, bool expect_success)
}

if (cpid == 0) { /* Code executed by child */
- setuid(child_uid);
+ if (setuid(child_uid) < 0)
+ exit(EXIT_FAILURE);
if (getuid() == child_uid)
exit(EXIT_SUCCESS);
else
@@ -291,8 +292,10 @@ int main(int argc, char **argv)

// First test to make sure we can write userns mappings from a user
// that doesn't have any restrictions (as long as it has CAP_SETUID);
- setuid(NO_POLICY_USER);
- setgid(NO_POLICY_USER);
+ if (setuid(NO_POLICY_USER) < 0)
+ die("Error with set uid(%d)\n", NO_POLICY_USER);
+ if (setgid(NO_POLICY_USER) < 0)
+ die("Error with set gid(%d)\n", NO_POLICY_USER);

// Take away all but setid caps
drop_caps(true);
@@ -306,8 +309,10 @@ int main(int argc, char **argv)
die("test_userns failed when it should work\n");
}

- setuid(RESTRICTED_PARENT);
- setgid(RESTRICTED_PARENT);
+ if (setuid(RESTRICTED_PARENT) < 0)
+ die("Error with set uid(%d)\n", RESTRICTED_PARENT);
+ if (setgid(RESTRICTED_PARENT) < 0)
+ die("Error with set gid(%d)\n", RESTRICTED_PARENT);

test_setuid(ROOT_USER, false);
test_setuid(ALLOWED_CHILD1, true);
--
2.20.1