Ceph MON crash with ceph_assert(z >= signedspan::zero()) in RHCS 4.x

Issue

• Ceph MON crashed in ceph::time_detail::timespan ceph::to_timespan(ceph::time_detail::signedspan)

  podman[123456]: debug 2020-07-16 02:16:20.249 76543210abcd -1 /builddir/build/BUILD/ceph-14.2.8/src/common/ceph_time.h: In function 'ceph::time_detail::timespan ceph::to_timespan(ceph::time_detail::signedspan)' thread 76543210abcd time 2020-07-16 02:16:20.248989
  podman[123456]: /builddir/build/BUILD/ceph-14.2.8/src/common/ceph_time.h: 485: FAILED ceph_assert(z >= signedspan::zero())
  podman[123456]:  ceph version 14.2.8-59.el8cp (53387608e81e6aa2487c952a604db06faa5b2cd0) nautilus (stable)
  podman[123456]:  1: (ceph::__ceph_assert_fail(char const*, char const*, int, char const*)+0x156) [0x76543606655a]
  podman[123456]:  2: (()+0x26c774) [0x765436066774]
  podman[123456]:  3: (Paxos::store_state(MMonPaxos*)+0xaef) [0x123455656abf]
  podman[123456]:  4: (Paxos::handle_commit(boost::intrusive_ptr<MonOpRequest>)+0x301) [0x123455656e71]
  podman[123456]:  5: (Paxos::dispatch(boost::intrusive_ptr<MonOpRequest>)+0x2f3) [0x12345565cf33]
  podman[123456]:  6: (Monitor::dispatch_op(boost::intrusive_ptr<MonOpRequest>)+0x1329) [0x1234555712e9]
  podman[123456]:  7: (Monitor::_ms_dispatch(Message*)+0xa23) [0x123455571f03]
  podman[123456]:  8: (Monitor::ms_dispatch(Message*)+0x2a) [0x1234555a36aa]
  podman[123456]:  9: (Dispatcher::ms_dispatch2(boost::intrusive_ptr<Message> const&)+0x2a) [0x12345559fe4a]
  podman[123456]:  10: (DispatchQueue::entry()+0x134a) [0x7654362b8a7a]
  podman[123456]:  11: (DispatchQueue::DispatchThread::entry()+0x11) [0x76543636d481]
  podman[123456]:  12: (()+0x82de) [0x765432d872de]
  podman[123456]:  13: (clone()+0x43) [0x765431abee83]
  podman[123456]: *** Caught signal (Aborted) **
  podman[123456]:  in thread 76543210abcd thread_name:ms