static int _regulator_enable(struct regulator_dev *rdev)
{
	int ret;

	/* check voltage and requested load before enabling */
	if (rdev->constraints &&
	    (rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_DRMS))
		drms_uA_update(rdev);

	if (rdev->use_count == 0) {
		/* The regulator may on if it's not switchable or left on */
		ret = _regulator_is_enabled(rdev);
		if (ret == -EINVAL || ret == 0) {
			if (!_regulator_can_change_status(rdev))
				return -EPERM;

			ret = _regulator_do_enable(rdev);
			if (ret < 0)
				return ret;

		} else if (ret < 0) {
			rdev_err(rdev, "is_enabled() failed: %d\n", ret);
			return ret;
		}
		/* Fallthrough on positive return values - already enabled */
	}

	rdev->use_count++;

	return 0;
}

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 Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.