Re: Bugreport on Ubuntu LTS: not ok - 2 Objects creation does not break ACLs with restrictive umask

[Jeff King <peff@peff.net>]

On Tue, Jun 05, 2012 at 03:28:07PM +0200, Matthieu Moy wrote:

> Stefan Beller <stefanbeller@googlemail.com> writes:
> 
> > Hi,
> >
> > so I applied that patch with git apply, but here 2 out of 4 tests now
> > still fail.
> 
> Yes, Jeff's patch checks for a "working" setfacl/getfacl, but does not
> check for subtle brokenness of it.
> 
> I'd say a filesystem that accepts setfacl, returns the right line in
> getfacl, and then does not really work is broken, and it's a feature
> that the testsuite shows test failures. A simple fix for you would be to
> disable ACLs, either on your system or in your $HOME.

I found the problem. If you create a file on an ecryptfs filesystem with
a restrictive mode, then the inherited mask bits get cleared. For
example:

  # if you don't have one already, create an ecryptfs mount; you
  # will need the ecryptfs-utils package on Debian and Ubuntu
  ecryptfs-setup-private
  ecryptfs-mount-private
  cd Private

  # now set up an inherited mask
  setfacl -m d:m:rwx .

  # and create some files with different permissions
  perl -MFcntl -e '
    sysopen(X, "a", O_WRONLY|O_CREAT, 0666);
    sysopen(X, "b", O_WRONLY|O_CREAT, 0600);
  '

  # and then check the permissions
  getfacl a b

which yields:

  # file: a
  # owner: peff
  # group: peff
  user::rw-
  group::---
  mask::r--
  other::---

  # file: b
  # owner: peff
  # group: peff
  user::rw-
  group::---
  mask::---
  other::---

That just seems wrong to me.

-Peff