As far as I can tell, patched OpenSSL packages for affected Debian/Ubuntu releases are not yet available.
https://security-tracker.debian.org/tracker/CVE-2016-6304
https://people.canonical.com/~ubuntu-security/cve/2016/CVE-2...
https://security-tracker.debian.org/tracker/CVE-2016-6304
https://people.canonical.com/~ubuntu-security/cve/2016/CVE-2...