From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Serge E. Hallyn" Subject: Re: [patch 07/10] unprivileged mounts: add sysctl tunable for "safe" property Date: Tue, 22 Jan 2008 14:48:28 -0600 Message-ID: <20080122204828.GA1212@sergelap.austin.ibm.com> References: <20080116123147.466284860@szeredi.hu> <20080116123433.126167584@szeredi.hu> <20080121203249.GB5536@sergelap.austin.rr.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: serue@us.ibm.com, akpm@linux-foundation.org, hch@infradead.org, viro@ftp.linux.org.uk, kzak@redhat.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, containers@lists.osdl.org, util-linux-ng@vger.kernel.org To: Miklos Szeredi Return-path: Received: from e1.ny.us.ibm.com ([32.97.182.141]:35933 "EHLO e1.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751557AbYAVUsb (ORCPT ); Tue, 22 Jan 2008 15:48:31 -0500 Content-Disposition: inline In-Reply-To: Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Quoting Miklos Szeredi (miklos@szeredi.hu): > > What do you think about doing this only if FS_SAFE is also set, > > so for instance at first only FUSE would allow itself to be > > made user-mountable? > > > > A safe thing to do, or overly intrusive? > > It goes somewhat against the "no policy in kernel" policy ;). I think > the warning in the documentation should be enough to make sysadmins > think twice before doing anything foolish: Warning in which documentation? A sysadmin considering setting fs_safe for ext2 or xfs isn't going to be looking at fuse docs, which I think is what you're talking about. Are you going to add a file under Documentation/filesystems? > > +Care should be taken when enabling this, since most > > +filesystems haven't been designed with unprivileged mounting > > +in mind. > > + > > BTW, filesystems like 'proc' and 'sysfs' should also be safe, although > the only use for them being marked safe is if the users are allowed to > umount them from their private namespace (otherwise a 'mount --bind' > has the same effect as a new mount). > > Thanks, > Miklos