Re: [PATCH] cifs: Fix getting reparse points from server without WSL support

[Jeremy Allison]

On Tue, Sep 17, 2024 at 10:29:21PM +0200, Pali Rohár wrote:
> On Tuesday 17 September 2024 13:23:40 Jeremy Allison wrote:
> > On Tue, Sep 17, 2024 at 10:06:00PM +0200, Pali Rohár wrote:
> > > And seems that SMB2_OP_QUERY_WSL_EA is useful not only for reparse
> > > points, but also for any regular file or directory as it can contain
> > > UNIX mode and UID/GID ownership.
> >
> > uid/gid should *never* be exposed over the wire for SMB.
> >
> > That way lies madness.
>
> Hello Jeremy, if I understood wsl_to_fattr() function correctly then it
> is already doing it, it fills uid/gid for stat() from data which were
> exposed over the wire for SMB. Could you check that function if it is
> truth?

I'm sure the Windows implementation is doing it - however, any Linux
server implementations should not do this (IMHO).

It will break all SID -> uid / gid mapping that servers must
carefully set up.

On the wire - SIDs must be the only source of identity.