In one example in accordance with the present disclosure, a system may comprise a memory accessor to access a memory and a pointer loader to load a virtual address (VA) pointer corresponding to a first location in the memory and a physical address (PA) pointer corresponding to the VA pointer. The system may comprise a pointer handler to determine a first physical address in the memory mapped to the first location in the memory and a location matcher to determine whether the second physical address mapped to the PA pointer matches the first physical address. The system may also comprise an exception handler to raise an exception when the second physical address does not match the first physical address.