The system's behavior seems back to normal after doing an "apt update" to apply updated packages from last night. dmesg does not list the general protection fault, and X starts normally.
The leading candidates look like libxcb_1.14-3 (from 1.14-2.1, although the changelog suggests not this one), hwloc15_2.4.1~rc1+dfsg-1 (from 2.4.0+dfsg-3), and lm-sensors_3.6.0-7 (from 3.6.0-6). If a full list of the updated packages would be helpful, I can provide it.
