selftests/memfd: sysctl: fix MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED

Add selftest for sysctl vm.memfd_noexec is 2
(MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED)

memfd_create(.., MFD_EXEC) should fail in this case.

Link: https://lkml.kernel.org/r/[email protected]
Reported-by: Dominique Martinet <[email protected]>
Closes: https://lore.kernel.org/linux-mm/CABi2SkXUX_QqTQ10Yx9bBUGpN1wByOi_=gZU6WEy5a8MaQY3Jw@mail.gmail.com/T/
Signed-off-by: Jeff Xu <[email protected]>
Cc: Daniel Verkamp <[email protected]>
Cc: Dmitry Torokhov <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Jann Horn <[email protected]>
Cc: Jorge Lucangeli Obes <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: kernel test robot <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Shuah Khan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

Author: Jeff Xu

tools/testing/selftests/memfd/memfd_test.c

@@ -1147,6 +1147,11 @@ static void test_sysctl_child(void)
 	sysctl_assert_write("2");
 	mfd_fail_new("kern_memfd_sysctl_2",
 		MFD_CLOEXEC | MFD_ALLOW_SEALING);
+	mfd_fail_new("kern_memfd_sysctl_2_MFD_EXEC",
+		MFD_CLOEXEC | MFD_EXEC);
+	fd = mfd_assert_new("", 0, MFD_NOEXEC_SEAL);
+	close(fd);
+
 	sysctl_fail_write("0");
 	sysctl_fail_write("1");
 }