From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751283AbdBXMMr (ORCPT ); Fri, 24 Feb 2017 07:12:47 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:56750 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751082AbdBXMMj (ORCPT ); Fri, 24 Feb 2017 07:12:39 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Gu Zheng" , "Al Viro" Date: Fri, 24 Feb 2017 12:10:01 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 08/12] tmpfs: clear S_ISGID when setting posix ACLs In-Reply-To: X-SA-Exim-Connect-IP: 82.70.136.246 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.41-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Gu Zheng commit 497de07d89c1410d76a15bec2bb41f24a2a89f31 upstream. This change was missed the tmpfs modification in In CVE-2016-7097 commit 073931017b49 ("posix_acl: Clear SGID bit when setting file permissions") It can test by xfstest generic/375, which failed to clear setgid bit in the following test case on tmpfs: touch $testfile chown 100:100 $testfile chmod 2755 $testfile _runas -u 100 -g 101 -- setfacl -m u::rwx,g::rwx,o::rwx $testfile Signed-off-by: Gu Zheng Signed-off-by: Al Viro Signed-off-by: Ben Hutchings --- fs/posix_acl.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) --- a/fs/posix_acl.c +++ b/fs/posix_acl.c @@ -904,11 +904,10 @@ int simple_set_acl(struct inode *inode, int error; if (type == ACL_TYPE_ACCESS) { - error = posix_acl_equiv_mode(acl, &inode->i_mode); - if (error < 0) - return 0; - if (error == 0) - acl = NULL; + error = posix_acl_update_mode(inode, + &inode->i_mode, &acl); + if (error) + return error; } inode->i_ctime = CURRENT_TIME;