From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from endymion.arp.harvard.edu (endymion.arp.harvard.edu [140.247.179.71]) by sourceware.org (Postfix) with ESMTPS id F1E5F3858D20 for ; Wed, 8 Feb 2023 21:05:50 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org F1E5F3858D20 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=huarp.harvard.edu Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=huarp.harvard.edu Received: from [10.245.83.21] (unknown [10.245.83.21]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by endymion.arp.harvard.edu (Postfix) with ESMTPSA id AFF3D26CBB2 for ; Wed, 8 Feb 2023 16:05:50 -0500 (EST) Content-Type: multipart/alternative; boundary="------------5dgFJoMRDdIOF8UvHMJX80c7" Message-ID: <0219f7c5-ca4c-bae3-3e13-abfc14c53e01@huarp.harvard.edu> Date: Wed, 8 Feb 2023 16:05:50 -0500 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.6.1 Content-Language: en-US From: Norton Allen To: "cygwin@cygwin.com" Subject: chmod g+ws unsuccessful, "NULL SID" icacls missing X-Spam-Status: No, score=-2.7 required=5.0 tests=BAYES_00,HTML_MESSAGE,KAM_DMARC_STATUS,SPF_HELO_NONE,SPF_PASS,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: This is a multi-part message in MIME format. --------------5dgFJoMRDdIOF8UvHMJX80c7 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit I briefly raised this issue months ago and am trying to resolve it again now. What I am trying to do is setup permissions so multiple users on one machine can share full control over a particular directory hierarchy. On Linux I have usually been able to make things work with: $ mkdir shared_dir $ chgrp shared_group shared_dir $ chmod g+ws shared_dir $ umask 2 User shells are configured with umask 2 so files they create have group write. Users belong to shared_group. Files and subdirs created under shared_dir are all in group shared_group. Files moved in retain their original group, but the group members still have permission to rename or delete them. The problem: $ chmod g+ws fails to set the 's' bit, and the resulting icacls output does not contain any "NULL SID" entries. I am seeing the same problem on (at least) two different systems setup by my organization. One of these was just re-imaged and I installed Cygwin yesterday with no customized configurations. AV is Windows Defender, but I suspect if that were the culprit, there would have been more noise. I suspect there might be a group policy or something that is interfering with Cygwin's strategy for implementing POSIX permissions. I am pretty sure this worked correctly at some point in the past. Has anyone encountered this? Does group policy seem like a likely suspect? Anyone know which policy(ies)? I think I might be able to get IT to cut me slack if I knew what to ask for. I have also played with using setfacl directly to add permissions, but as anyone who has read about Cygwin file permissions might guess, that tends to have mixed/poor results, but I'd be open to any suggestions. --------------5dgFJoMRDdIOF8UvHMJX80c7--