Fix the length calculation for the final block of a sendfile(2)
transmission which could be tricked into rounding up to the nearest
page size, leaking up to a page of kernel memory. [13:11]

In IPv6 and NetATM, stop SIOCSIFADDR, SIOCSIFBRDADDR, SIOCSIFDSTADDR
and SIOCSIFNETMASK at the socket layer rather than pass them on to the
link layer without validation or credential checks. [SA-13:12]

Prevent cross-mount hardlinks between different nullfs mounts of the
same underlying filesystem. [SA-13:13]

Security: CVE-2013-5666
Security: FreeBSD-SA-13:11.sendfile
Security: CVE-2013-5691
Security: FreeBSD-SA-13:12.ifioctl
Security: CVE-2013-5710
Security: FreeBSD-SA-13:13.nullfs
Approved by: re