That is an interesting solution. The error suggests the faulty part is the L1 cache of CPU2. As the L1 cache is one per core, disabling CPU2 does solve the problem.
Here's something to help. You can activate CPU3 so you can have 3 cores running by making sure you have 'CONFIG_HOTPLUG_CPU' enabled in the kernel and running:
echo 1 > /sys/devices/system/cpu/cpu3/online