static struct regulator *_regulator_get(struct device *dev, const char *id,
					bool exclusive, bool allow_dummy)
{
	struct regulator_dev *rdev;
	struct regulator *regulator = ERR_PTR(-EPROBE_DEFER);
	const char *devname = NULL;
	int ret;

	if (id == NULL) {
		pr_err("get() with no identifier\n");
		return ERR_PTR(-EINVAL);
	}

	if (dev)
		devname = dev_name(dev);

	if (have_full_constraints())
		ret = -ENODEV;
	else
		ret = -EPROBE_DEFER;

	mutex_lock(&regulator_list_mutex);

	rdev = regulator_dev_lookup(dev, id, &ret);
	if (rdev)
		goto found;

	regulator = ERR_PTR(ret);

	/*
	 * If we have return value from dev_lookup fail, we do not expect to
	 * succeed, so, quit with appropriate error value
	 */
	if (ret && ret != -ENODEV)
		goto out;

	if (!devname)
		devname = "deviceless";

	/*
	 * Assume that a regulator is physically present and enabled
	 * even if it isn't hooked up and just provide a dummy.
	 */
	if (have_full_constraints() && allow_dummy) {
		pr_warn("%s supply %s not found, using dummy regulator\n",
			devname, id);

		rdev = dummy_regulator_rdev;
		goto found;
	/* Don't log an error when called from regulator_get_optional() */
	} else if (!have_full_constraints() || exclusive) {
		dev_warn(dev, "dummy supplies not allowed\n");
	}

	mutex_unlock(&regulator_list_mutex);
	return regulator;

found:
	if (rdev->exclusive) {
		regulator = ERR_PTR(-EPERM);
		goto out;
	}

	if (exclusive && rdev->open_count) {
		regulator = ERR_PTR(-EBUSY);
		goto out;
	}

	if (!try_module_get(rdev->owner))
		goto out;

	regulator = create_regulator(rdev, dev, id);
	if (regulator == NULL) {
		regulator = ERR_PTR(-ENOMEM);
		module_put(rdev->owner);
		goto out;
	}

	rdev->open_count++;
	if (exclusive) {
		rdev->exclusive = 1;

		ret = _regulator_is_enabled(rdev);
		if (ret > 0)
			rdev->use_count = 1;
		else
			rdev->use_count = 0;
	}

out:
	mutex_unlock(&regulator_list_mutex);

	return regulator;
}

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 Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.