Comment 39 for bug 1724650

Your cpu is:

[ 0.162937] smpboot: CPU0: Intel(R) Core(TM) M-5Y31 CPU @ 0.90GHz (family: 0x6, model: 0x3d, stepping: 0x4)

The latest Intel microcode, release 20170707, contains:

$ iucode-tool -L 06-3d-04
microcode bundle 1: 06-3d-04
  001/001: sig 0x000306d4, pf_mask 0xc0, 2017-01-27, rev 0x0025, size 17408

The latest Ubuntu 17.10 intel-microcode package contains:

$ iucode-tool -l microcode-20170707.dat | grep 306d4
  001/141: sig 0x000306d4, pf_mask 0xc0, 2017-01-27, rev 0x0025, size 17408

So it already contains your fixed ucode, you just need to install intel-microcode and reboot.