MFC r362568:

MFV r362565:

Update 4.2.8p14 --> 4.2.8p15

Summary: Systems that use a CMAC algorithm in ntp.keys will not release
a bit of memory on each packet that uses a CMAC keyid, eventually causing
ntpd to run out of memory and fail. The CMAC cleanup from
https://bugs.ntp.org/3447, part of ntp-4.2.8p11, introduced a bug whereby
the CMAC data structure was no longer completely removed.

Security: NTP Bug 3661

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFV r293415:

ntp 4.2.8p5

Reviewed by: cy, roberto
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D4828

MFV ntp 4.2.8p1 (r258945, r275970, r276091, r276092, r276093, r278284)

Thanks to roberto for providing pointers to wedge this into HEAD.

Approved by: roberto

Virgin import of ntpd 4.2.6p5.

When the series of commits is complete, things like
https://cert.litnet.lt/en/docs/ntp-distributed-reflection-dos-attacks
should be fixed.

PR: bin/148836 (except that we import a newer version)
Asked by: Too many
MFC after: 2 weeks