Did it look sorta like this?
CPU 0: Machine Check Exception: 0000000000000004
BANK 0: f648600022000800 at
76486000222000800 Kernel Panic: CPU context corrupt
A machine check can be signaled by the processor when it thinks it is in an invalid state. Many x86 processors have checking circuitry and the default behavior is to either reboot or try and recover from the problem. Linux enables notification of these events.
In many cases this error usually signals some sort of internal hardware problem related to the processor. The processor could have run into a problem because of wrong voltages, electrical noise, overheating and many other things.
In most cases the processor needs to be replaced, but the problem can also be generated by overclocking and poorly fitted heatsinks.
Before replacing the processor, make sure the processor is getting adequate cooling. Check the heatsink on the processor for proper fit and that the heatsink has been tested for use with your processor. Other items to check are the voltage regulator modules (VRMs), which regulate the amount of power that goes to the CPU. A degraded VRM, if left unchecked, can lead to permanent processor damage. If you are unsure of how to check these items, your hardware vendor's technical support should be able to assist you.
Usually a CPU machine exception of any sort does point back to hardware...usually CPU, Memory, or system board.