[BUGFIX PATCH 0/2] selftests: safesetid: Fix build warnings and errors

[BUGFIX PATCH 0/2] selftests: safesetid: Fix build warnings and errors

[Masami Hiramatsu]

Hi,

Here are the patches to fix build warnings and erorrs on
kselftest safesetid.

Thank you,

---

Masami Hiramatsu (2):
      selftests: safesetid: Move link library to LDLIBS
      selftests: safesetid: Check the return value of setuid/setgid


 tools/testing/selftests/safesetid/Makefile         |    3 ++-
 tools/testing/selftests/safesetid/safesetid-test.c |   15 ++++++++++-----
 2 files changed, 12 insertions(+), 6 deletions(-)

--
Masami Hiramatsu (Linaro) <mhiramat@kernel.org>

[BUGFIX PATCH 1/2] selftests: safesetid: Move link library to LDLIBS

[Masami Hiramatsu]

Move -lcap to LDLIBS from CFLAGS because it is a library
to be linked.

Without this, safesetid failed to build with link error
as below.

----
/usr/bin/ld: /tmp/ccL8rZHT.o: in function `drop_caps':
safesetid-test.c:(.text+0xe7): undefined reference to `cap_get_proc'
/usr/bin/ld: safesetid-test.c:(.text+0x107): undefined reference to `cap_set_flag'
/usr/bin/ld: safesetid-test.c:(.text+0x10f): undefined reference to `cap_set_proc'
/usr/bin/ld: safesetid-test.c:(.text+0x117): undefined reference to `cap_free'
/usr/bin/ld: safesetid-test.c:(.text+0x136): undefined reference to `cap_clear'
collect2: error: ld returned 1 exit status
----

Fixes: c67e8ec03f3f ("LSM: SafeSetID: add selftest")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
 tools/testing/selftests/safesetid/Makefile |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/safesetid/Makefile b/tools/testing/selftests/safesetid/Makefile
index 98da7a504737..cac42cd36a1b 100644
--- a/tools/testing/selftests/safesetid/Makefile
+++ b/tools/testing/selftests/safesetid/Makefile
@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 # Makefile for mount selftests.
-CFLAGS = -Wall -lcap -O2
+CFLAGS = -Wall -O2
+LDLIBS = -lcap
 
 TEST_PROGS := run_tests.sh
 TEST_GEN_FILES := safesetid-test

[BUGFIX PATCH 2/2] selftests: safesetid: Check the return value of setuid/setgid

[Masami Hiramatsu]

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>
---
 tools/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);

Re: [BUGFIX PATCH 0/2] selftests: safesetid: Fix build warnings and errors

[Masami Hiramatsu]

On Thu,  5 Dec 2019 16:33:12 +0900
Masami Hiramatsu <mhiramat@kernel.org> wrote:

> Hi,
> 
> Here are the patches to fix build warnings and erorrs on
> kselftest safesetid.

Oops, I found one another bug in safesetid. I'll send v2 including
new fix.

Thank you,

> 
> Thank you,
> 
> ---
> 
> Masami Hiramatsu (2):
>       selftests: safesetid: Move link library to LDLIBS
>       selftests: safesetid: Check the return value of setuid/setgid
> 
> 
>  tools/testing/selftests/safesetid/Makefile         |    3 ++-
>  tools/testing/selftests/safesetid/safesetid-test.c |   15 ++++++++++-----
>  2 files changed, 12 insertions(+), 6 deletions(-)
> 
> --
> Masami Hiramatsu (Linaro) <mhiramat@kernel.org>


-- 
Masami Hiramatsu <mhiramat@kernel.org>