Interestingly your ASRock board also seems to have the clocksource instability/calibration problem when overclocked via the BIOS.
A workaround is to OC from within linux itself rather than via the BIOS settings:
For now, post the output of this command
cat /sys/devices/system/clocksource/clocksource0/current_clocksource
If I’m correct it will report hpet, under normal circumstances it should be tsc. But that’s not the only issue.
I’m also suspicious of this line:
[ 71.268601] acpi_cpufreq: overriding BIOS provided _PSD data
Since I don’t think that code has yet been adapted for Ryzen
As for Vbox I’m not exactly sure what’s going on there. It’s creating IOMMU domains and freeing them before the log ends. Chances are that the log is also not fully written out to disk when the crash occurs.
Try connecting to the machine via ssh from another system and view journalctl or dmesg with journalctl -f / dmesg -w to catch the output on another machine.