Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754208AbdGSJrJ (ORCPT ); Wed, 19 Jul 2017 05:47:09 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:38254 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754190AbdGSJrF (ORCPT ); Wed, 19 Jul 2017 05:47:05 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Naresh Kamboju , "Eric W. Biederman" , Kees Cook , Shuah Khan , Greg KH , linux-kselftest@vger.kernel.org, Andy Lutomirski Subject: [PATCH 4.12 64/84] selftests/capabilities: Fix the test_execve test Date: Wed, 19 Jul 2017 11:44:10 +0200 Message-Id: <20170719092324.859704113@linuxfoundation.org> X-Mailer: git-send-email 2.13.3 In-Reply-To: <20170719092322.362625377@linuxfoundation.org> References: <20170719092322.362625377@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2654 Lines: 74 4.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andy Lutomirski commit 796a3bae2fba6810427efdb314a1c126c9490fb3 upstream. 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: "Eric W. Biederman" Cc: Kees Cook Cc: Shuah Khan Cc: Greg KH Cc: linux-kselftest@vger.kernel.org Signed-off-by: Andy Lutomirski Acked-by: Greg Kroah-Hartman Signed-off-by: Shuah Khan Signed-off-by: Greg Kroah-Hartman --- tools/testing/selftests/capabilities/test_execve.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) --- 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 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 } 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");