void kvm_vcpu_on_spin(struct kvm_vcpu *me)
{
	struct kvm *kvm = me->kvm;
	struct kvm_vcpu *vcpu;
	int last_boosted_vcpu = me->kvm->last_boosted_vcpu;
	int yielded = 0;
	int try = 3;
	int pass;
	int i;

	kvm_vcpu_set_in_spin_loop(me, true);
	/*
	 * We boost the priority of a VCPU that is runnable but not
	 * currently running, because it got preempted by something
	 * else and called schedule in __vcpu_run.  Hopefully that
	 * VCPU is holding the lock that we need and will release it.
	 * We approximate round-robin by starting at the last boosted VCPU.
	 */
	for (pass = 0; pass < 2 && !yielded && try; pass++) {
		kvm_for_each_vcpu(i, vcpu, kvm) {
			if (!pass && i <= last_boosted_vcpu) {
				i = last_boosted_vcpu;
				continue;
			} else if (pass && i > last_boosted_vcpu)
				break;
			if (!ACCESS_ONCE(vcpu->preempted))
				continue;
			if (vcpu == me)
				continue;
			if (swait_active(&vcpu->wq) && !kvm_arch_vcpu_runnable(vcpu))
				continue;
			if (!kvm_vcpu_eligible_for_directed_yield(vcpu))
				continue;

			yielded = kvm_vcpu_yield_to(vcpu);
			if (yielded > 0) {
				kvm->last_boosted_vcpu = i;
				break;
			} else if (yielded < 0) {
				try--;
				if (!try)
					break;
			}
		}
	}
	kvm_vcpu_set_in_spin_loop(me, false);

	/* Ensure vcpu is not eligible during next spinloop */
	kvm_vcpu_set_dy_eligible(me, false);
}

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.