Pull up following revision(s) (requested by maxv in ticket #1565):
sys/dist/pf/net/pf.c: revision 1.78 via patch
Oh, what is this. Fix a remotely-triggerable integer overflow: the way we
define TCPOLEN_SACK makes it unsigned, and the comparison in the while()
is unsigned too. That's not the expected behavior, the original code
wanted a signed comparison.
It's pretty easy to make 'hlen' go negative and trigger a buffer overflow.
This bug was reported 8 years ago by Lucio Albornoz in PR/44059.

(snj)