This is old post but shown by google search so might be helpful for other people experiencing similar problem:
BY default cifs mounts with owner = root and permissions of 755. You can set dir_mode to 777 when mounting:
sudo mount -t cifs //192.xxx.x.xx/media /mnt/unraidtower -o username=pi,password=raspberry,dir_mode=0777,file_mode=0777