static void perf_group_detach(struct perf_event *event)
{
	struct perf_event *sibling, *tmp;
	struct list_head *list = NULL;

	lockdep_assert_held(&event->ctx->lock);

	/*
	 * We can have double detach due to exit/hot-unplug + close.
	 */
	if (!(event->attach_state & PERF_ATTACH_GROUP))
		return;

	event->attach_state &= ~PERF_ATTACH_GROUP;

	/*
	 * If this is a sibling, remove it from its group.
	 */
	if (event->group_leader != event) {
		list_del_init(&event->group_entry);
		event->group_leader->nr_siblings--;
		goto out;
	}

	if (!list_empty(&event->group_entry))
		list = &event->group_entry;

	/*
	 * If this was a group event with sibling events then
	 * upgrade the siblings to singleton events by adding them
	 * to whatever list we are on.
	 */
	list_for_each_entry_safe(sibling, tmp, &event->sibling_list, group_entry) {
		if (list)
			list_move_tail(&sibling->group_entry, list);
		sibling->group_leader = sibling;

		/* Inherit group flags from the previous leader */
		sibling->group_caps = event->group_caps;

		WARN_ON_ONCE(sibling->ctx != event->ctx);
	}

out:
	perf_event__header_size(event->group_leader);

	list_for_each_entry(tmp, &event->group_leader->sibling_list, group_entry)
		perf_event__header_size(tmp);
}

The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.