[PATCHES][BUG 13673] smbd: Fix DELETE_ON_CLOSE behaviour on files with READ_ONLY attribute

[Christof Schmitt]

On Fri, Nov 02, 2018 at 01:53:55PM -0700, Jeremy Allison via samba-technical wrote:
> On Fri, Nov 02, 2018 at 01:29:55PM -0700, Christof Schmitt via samba-technical wrote:
> > smbd allowed CREATE on a file with the READONLY attribute set and
> > DELETE_ON_CLOSE requested, even though MS-FSA states that this should be
> > denied. On the other hand, SETINFO for DELETE_ON_CLOSE is correctly
> > rejected.
> > 
> > See the attached patches for a fix. This also adds a smbtorture test for
> > this case and the Samba override 'delete readonly=yes'
> > 
> > gitlab pipeline
> > https://gitlab.com/samba-team/devel/samba/pipelines/35263504
> 
> Oh this is a great catch ! How did you find it ?

Long story. For a special case we had some testing done of trying to
delete files with READONLY set. This showed differences between trying
this from Powershell or cmd.exe. It turns out that this triggers two
different patterns (CREATE then SETINFO-DELETE_ON_CLOSE vs.
CREATE-DELET_ON_CLOSE). Samba allowing one while denying the other
seemed inconsistent.

> 
> Reviewing now...

Please hold on. This fails the base.delete.deltest12 test for Samba, but
the same succeeds against a Windows server:

$ bin/smbtorture ... base.delete.deltest12 smb2.delete-on-close-perms.READONLY
smbtorture 4.10.0pre1-DEVELOPERBUILD
Using seed 1541192134
time: 2018-11-02 20:55:34.630579
test: deltest12
time: 2018-11-02 20:55:34.630684
time: 2018-11-02 20:55:37.730715
success: deltest12
time: 2018-11-02 20:55:37.739500
test: READONLY
time: 2018-11-02 20:55:37.741927
Creating file with READ_ONLY attribute.
Testing CREATE with DELETE_ON_CLOSE on READ_ONLY attribute file.
Testing setting DELETE_ON_CLOSE disposition on  file with READONLY
attribute.
time: 2018-11-02 20:55:42.679877
success: READONLY

I will look into this, maybe this is different in SMB1 vs. SMB2/3.

Christof