recent cmsghdr fixes

[Taylor R Campbell <campbell%mumble.net@localhost>]

In June after a brief discussion on netbsd-users@, the kernel was
fixed to check for the correct lengths in msghdr and cmsghdr ancillary
data.  Is there any chance that these fixes (revisions 1.116 and 1.117
of src/sys/kern/uipc_usrreq.c) will be back-ported to the netbsd-4
branch or others?  They only prevent a signed arithmetic mistake and
expand the domain of inputs from userland to include correct ones, so
I think that these changes are completely backward compatible and
useful to make correctly written programs run on any NetBSD version.
Since I run NetBSD 4.0_STABLE, this is useful to me.

(I'm not subscribed to this list, so please cc me in replies.)