static int set_machine_constraints(struct regulator_dev *rdev,
	const struct regulation_constraints *constraints)
{
	int ret = 0;
	const struct regulator_ops *ops = rdev->desc->ops;

	if (constraints)
		rdev->constraints = kmemdup(constraints, sizeof(*constraints),
					    GFP_KERNEL);
	else
		rdev->constraints = kzalloc(sizeof(*constraints),
					    GFP_KERNEL);
	if (!rdev->constraints)
		return -ENOMEM;

	ret = machine_constraints_voltage(rdev, rdev->constraints);
	if (ret != 0)
		goto out;

	ret = machine_constraints_current(rdev, rdev->constraints);
	if (ret != 0)
		goto out;

	/* do we need to setup our suspend state */
	if (rdev->constraints->initial_state) {
		ret = suspend_prepare(rdev, rdev->constraints->initial_state);
		if (ret < 0) {
			rdev_err(rdev, "failed to set suspend state\n");
			goto out;
		}
	}

	if (rdev->constraints->initial_mode) {
		if (!ops->set_mode) {
			rdev_err(rdev, "no set_mode operation\n");
			ret = -EINVAL;
			goto out;
		}

		ret = ops->set_mode(rdev, rdev->constraints->initial_mode);
		if (ret < 0) {
			rdev_err(rdev, "failed to set initial mode: %d\n", ret);
			goto out;
		}
	}

	/* If the constraints say the regulator should be on at this point
	 * and we have control then make sure it is enabled.
	 */
	if (rdev->constraints->always_on || rdev->constraints->boot_on) {
		ret = _regulator_do_enable(rdev);
		if (ret < 0 && ret != -EINVAL) {
			rdev_err(rdev, "failed to enable\n");
			goto out;
		}
	}

	if ((rdev->constraints->ramp_delay || rdev->constraints->ramp_disable)
		&& ops->set_ramp_delay) {
		ret = ops->set_ramp_delay(rdev, rdev->constraints->ramp_delay);
		if (ret < 0) {
			rdev_err(rdev, "failed to set ramp_delay\n");
			goto out;
		}
	}

	print_constraints(rdev);
	return 0;
out:
	kfree(rdev->constraints);
	rdev->constraints = NULL;
	return ret;
}

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 Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.