Linux cifs share allow different user than mounted/masked uid to do cp -p

Solution 1:

We have, at times, needed to use posix extended attributes (ACLs) to give multiple users access to a set of files through a CIFS server that does not authenticate to our central directory service. So for example you could try using setfacl on the SMB server, to map permissions onto files/folders, that will give the correct access to users on the Linux client(s). If you try this, don't forget to set the default ACL, too (this mimics the idea of inheritance on CIFS, although not perfectly).

If the users start twiddling the permissions themselves, it can get messy in a hurry. But I think your problem can probably be solved this way.