__intel_shared_reg_get_constraints(struct cpu_hw_events *cpuc,
				   struct perf_event *event,
				   struct hw_perf_event_extra *reg)
{
	struct event_constraint *c = &emptyconstraint;
	struct er_account *era;
	unsigned long flags;
	int idx = reg->idx;

	/*
	 * reg->alloc can be set due to existing state, so for fake cpuc we
	 * need to ignore this, otherwise we might fail to allocate proper fake
	 * state for this extra reg constraint. Also see the comment below.
	 */
	if (reg->alloc && !cpuc->is_fake)
		return NULL; /* call x86_get_event_constraint() */

again:
	era = &cpuc->shared_regs->regs[idx];
	/*
	 * we use spin_lock_irqsave() to avoid lockdep issues when
	 * passing a fake cpuc
	 */
	raw_spin_lock_irqsave(&era->lock, flags);

	if (!atomic_read(&era->ref) || era->config == reg->config) {

		/*
		 * If its a fake cpuc -- as per validate_{group,event}() we
		 * shouldn't touch event state and we can avoid doing so
		 * since both will only call get_event_constraints() once
		 * on each event, this avoids the need for reg->alloc.
		 *
		 * Not doing the ER fixup will only result in era->reg being
		 * wrong, but since we won't actually try and program hardware
		 * this isn't a problem either.
		 */
		if (!cpuc->is_fake) {
			if (idx != reg->idx)
				intel_fixup_er(event, idx);

			/*
			 * x86_schedule_events() can call get_event_constraints()
			 * multiple times on events in the case of incremental
			 * scheduling(). reg->alloc ensures we only do the ER
			 * allocation once.
			 */
			reg->alloc = 1;
		}

		/* lock in msr value */
		era->config = reg->config;
		era->reg = reg->reg;

		/* one more user */
		atomic_inc(&era->ref);

		/*
		 * need to call x86_get_event_constraint()
		 * to check if associated event has constraints
		 */
		c = NULL;
	} else {
		idx = intel_alt_er(idx);
		if (idx != reg->idx) {
			raw_spin_unlock_irqrestore(&era->lock, flags);
			goto again;
		}
	}
	raw_spin_unlock_irqrestore(&era->lock, flags);

	return c;
}

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.