From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:48412 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753622AbdF2PqV (ORCPT ); Thu, 29 Jun 2017 11:46:21 -0400 From: Andy Lutomirski To: Naresh Kamboju , Shuah Khan Cc: Andy Lutomirski , stable@vger.kernel.org, "Eric W. Biederman" , Kees Cook , Greg KH , linux-kselftest@vger.kernel.org Subject: [PATCH] selftests/capabilities: Fix the test_execve test Date: Thu, 29 Jun 2017 08:46:12 -0700 Message-Id: <57f82c0dce0388bdc38da5f45fbe0c8999a0bbbc.1498751145.git.luto@kernel.org> Sender: stable-owner@vger.kernel.org List-ID: test_execve does rather odd mount manipulations to safely create temporary setuid and setgid executables that aren't visible to the rest of the system. Those executables end up in the test's cwd, but that cwd is MNT_DETACHed. The core namespace code considers MNT_DETACHed trees to belong to no mount namespace at all and, in general, MNT_DETACHed trees are only barely function. This interacted with commit 380cf5ba6b0a ("fs: Treat foreign mounts as nosuid") to cause all MNT_DETACHed trees to act as though they're nosuid, breaking the test. Fix it by just not detaching the tree. It's still in a private mount namespace and is therefore still invisible to the rest of the system (except via /proc, and the same nosuid logic will protect all other programs on the system from believing in test_execve's setuid bits). While we're at it, fix some blatant whitespace problems. Reported-by: Naresh Kamboju Fixes: 380cf5ba6b0a ("fs: Treat foreign mounts as nosuid") Cc: stable@vger.kernel.org Cc: "Eric W. Biederman" Cc: Kees Cook Cc: Shuah Khan Cc: Greg KH Cc: linux-kselftest@vger.kernel.org Signed-off-by: Andy Lutomirski --- tools/testing/selftests/capabilities/test_execve.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/tools/testing/selftests/capabilities/test_execve.c b/tools/testing/selftests/capabilities/test_execve.c index 10a21a958aaf..763f37fecfb8 100644 --- a/tools/testing/selftests/capabilities/test_execve.c +++ b/tools/testing/selftests/capabilities/test_execve.c @@ -138,9 +138,6 @@ static void chdir_to_tmpfs(void) if (chdir(cwd) != 0) err(1, "chdir to private tmpfs"); - - if (umount2(".", MNT_DETACH) != 0) - err(1, "detach private tmpfs"); } static void copy_fromat_to(int fromfd, const char *fromname, const char *toname) @@ -248,7 +245,7 @@ static int do_tests(int uid, const char *our_path) err(1, "chown"); if (chmod("validate_cap_sgidnonroot", S_ISGID | 0710) != 0) err(1, "chmod"); -} + } capng_get_caps_process(); @@ -384,7 +381,7 @@ static int do_tests(int uid, const char *our_path) } else { printf("[RUN]\tNon-root +ia, sgidnonroot => i\n"); exec_other_validate_cap("./validate_cap_sgidnonroot", - false, false, true, false); + false, false, true, false); if (fork_wait()) { printf("[RUN]\tNon-root +ia, sgidroot => i\n"); -- 2.9.4