Hi @jbyrne,
To capture the CIFS share, use a windows file system agent which will also capture the permissions as well. For NFS you’ll need to use a linux file system agent instead, as it understands the intricacies (and permissions) of NFS. At restore time there is a checkbox that allows you to restore with or without the ACLs/Permissions.
There is a whitepaper on backing up CIFS/SMB and NFS shares. Why it doesn't discuss this topic in detail, it does make mention of it:
Some advantages in using Commvault software’s NAS client with CIFS/NFS support include: End user security support using backup of Windows (ACL) or UNIX (Permissions). Appropriate end user permissions are necessary when browsing or restoring individual data files via Commvault’s Web Console interface.