Stable kernel updates

Greg Kroah-Hartman has released a number of stable kernels over the last
few days, 3.18.126 on November 22, and,
on November 23: 4.19.4, 4.14.83, and 4.9.139. Two problems were reported for
4.9.139, which quickly led to the release of 4.9.140. As usual, these kernels contain
important fixes; users of those series should upgrade.