2014-04-18 16:39:20

by Christoph Hellwig

[permalink] [raw]
Subject: Re: [PATCH v2 1/2] xfs: fix tmpfile/selinux deadlock and initialize security/acl

On Wed, Apr 16, 2014 at 07:29:29PM +0200, Andreas Gruenbacher wrote:
> > Btw, I think the man page is wrong - given that the tmpfile is not
> > visible in the namespace it is obviously not created in the directory.
> > The directory passed in is just a handle for the filesystem it should be
> > created in.
>
> I don't agree. If the file is created with O_TMPFILE | O_EXCL, it is clear
> that the file will never be linked into the namespace. Even then, there are
> operations which are affected by the inode permissions and label of the
> anonymous file, and those should still behave reasonably. In this context,
> I would expect them to behave as if the file was actually created in the
> specified directory, not in the file system root or "nowhere" with no clearly
> defined permissions and security label.

So you want to define the files as being in a directory, but not
actually visible? That's defintively a new and strange state to be in.

> > Inheriting any ACL on creating an anonymous file seems utterly wrong.
>
> Why?

Because it has no parent to inherit it from.