This patch belongs to CERT advisory CA-98-13.
(see also http://www.cert.org/advisories/CA-98-13-tcp-denial-of-service.html)

The patch applies to FreeBSD 3.0 as all 2.2 releases.
FreeBSD 2.2.8 is not vulnerable.
FreeBSD 3.0-current as of 1998/11/12 is not vulnerable.