Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934455AbcKILQP (ORCPT ); Wed, 9 Nov 2016 06:16:15 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:56320 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933692AbcKILP1 (ORCPT ); Wed, 9 Nov 2016 06:15:27 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Amir Goldstein , Miklos Szeredi Subject: [PATCH 4.8 077/138] ovl: update S_ISGID when setting posix ACLs Date: Wed, 9 Nov 2016 11:46:00 +0100 Message-Id: <20161109102848.392908869@linuxfoundation.org> X-Mailer: git-send-email 2.10.2 In-Reply-To: <20161109102844.808685475@linuxfoundation.org> References: <20161109102844.808685475@linuxfoundation.org> User-Agent: quilt/0.64 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: 1544 Lines: 51 4.8-stable review patch. If anyone has any objections, please let me know. ------------------ From: Miklos Szeredi commit fd3220d37b1f6f0cab6142d98b0e6c4082e63299 upstream. This change fixes xfstest generic/375, which failed to clear the setgid bit in the following test case on overlayfs: touch $testfile chown 100:100 $testfile chmod 2755 $testfile _runas -u 100 -g 101 -- setfacl -m u::rwx,g::rwx,o::rwx $testfile Reported-by: Amir Goldstein Signed-off-by: Miklos Szeredi Tested-by: Amir Goldstein Fixes: d837a49bd57f ("ovl: fix POSIX ACL setting") Signed-off-by: Greg Kroah-Hartman --- fs/overlayfs/super.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -1026,6 +1026,21 @@ ovl_posix_acl_xattr_set(const struct xat posix_acl_release(acl); + /* + * Check if sgid bit needs to be cleared (actual setacl operation will + * be done with mounter's capabilities and so that won't do it for us). + */ + if (unlikely(inode->i_mode & S_ISGID) && + handler->flags == ACL_TYPE_ACCESS && + !in_group_p(inode->i_gid) && + !capable_wrt_inode_uidgid(inode, CAP_FSETID)) { + struct iattr iattr = { .ia_valid = ATTR_KILL_SGID }; + + err = ovl_setattr(dentry, &iattr); + if (err) + return err; + } + err = ovl_xattr_set(dentry, handler->name, value, size, flags); if (!err) ovl_copyattr(ovl_inode_real(inode, NULL), inode);