If I back up a file with capabilities, using something like this:

    # tar cvf /tmp/ping.tar --xattrs --selinux --acls /usr/bin/ping

...and then untar it afterward:

    # tar xvf /tmp/ping.tar --xattrs --selinux --acls

...the resulting file does not have its file caps preserved. Stracing those commands shows that it queries the security.capability xattr when tarring, but the untar does not attempt to set that value.

Perhaps we need a --capabilities flag for tar?