Return-Path: Received: from fieldses.org ([173.255.197.46]:58952 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932642AbeENOcW (ORCPT ); Mon, 14 May 2018 10:32:22 -0400 Date: Mon, 14 May 2018 10:32:22 -0400 From: "J. Bruce Fields" To: Lu Xinyu Cc: linux-nfs@vger.kernel.org Subject: Re: SGID loss with nfsv3 Message-ID: <20180514143222.GA7160@fieldses.org> References: <20180430201623.GA3207@fieldses.org> <060c9d41-8772-80e1-e938-21ec7b6315ef@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <060c9d41-8772-80e1-e938-21ec7b6315ef@cn.fujitsu.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Mon, May 14, 2018 at 02:43:49PM +0800, Lu Xinyu wrote: > Hi,Bruce > > On 20180501 04:16, J. Bruce Fields wrote: > > On Wed, Apr 25, 2018 at 02:03:20PM +0800, Lu Xinyu wrote: > >> hi, folks > >> > >> > >> I have client and server using nfsv3. The kernels are all 4.16-rc3. > >> In client I mount a partition or a disk formatted in xfs/ext4 in > >> /nfstest. It seems there is someting wrong with inheritance of sgid. I > >> try the following operations in the client. > >>> [root@localhost ]#id user1 > >>> uid=1003(user1) gid=1006(testgroup1) > >> groups=1006(testgroup1),1007(testgroup2) > >>> [root@localhost ]# mount -t nfs -o vers=3 -o noac > >> 192.168.56.9:/data/nfstest /mnt/test/ > >>> [root@localhost ]# cd /mnt/test/ > >>> [root@localhost ]# mkdir mainsub > >>> [root@localhost ]# setfacl -d -m u:user2:rwx mainsub/ > >>> [root@localhost ]# chown user1:testgroup1 mainsub/ > >>> # chmod 2775 mainsub/ > >>> [root@localhost ]# runuser -u user1 -g testgroup1 mkdir mainsub/subdir1 > >>> [root@localhost ]# runuser -u user1 -g testgroup2 mkdir mainsub/subdir2 > >>> [root@localhost ]# ls -l mainsub/ > >>> drwxrwsr-x+ 2 user1 testgroup1 4096 Mar 6 22:50 subdir1 > >>> drwxrwxr-x+ 2 user1 testgroup1 4096 Mar 6 22:50 subdir2 > >> > >> > >> The subdir2 losts SGID. But if the same operations are applied in the > >> xfs or ext4 directedly, the SGID could be interited normally. > >> > >>> [root@localhost ]# ls -l mainsub/ > >>> drwxrwsr-x+ 2 user1 testgroup1 4096 Mar 6 22:55 subdir1 > >>> drwxrwsr-x+ 2 user1 testgroup1 4096 Mar 6 22:55 subdir2 > >> > >> Is this a bug of NFSv3? > >> > >>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=073931017b49d9458aa351605b43a7e34598caef > >> > >> > >> Clear SGID bit when setting file permissions > >> > >> It seems this patch will clear the nfs sgid. Should we keep it? > > > > Just searching for that commit id.... It looks like this was fixed by > > ext4 by a3bb2d5587521eea6dab2d05326abb0afb460abd "ext4: Don't clear SGID > > when inheriting ACLs". And there are similar patches for a bunch of > > other filesystems. > > > > --b. > > > Thanks for reply. > The SGID will not be cleared on the xfs. However, when it mounts a nfs > the SGID will get lost. I think it is a NFS bug. Also, I should have noticed that the fixes I mentioned are already in the kernel you're testing. Maybe nfs or knfsd needed a corresponding fix. I can't remember if you posted a network trace--that would help assign blame to the client or the server side. --b.