static int regulator_mode_constrain(struct regulator_dev *rdev, int *mode)
{
	switch (*mode) {
	case REGULATOR_MODE_FAST:
	case REGULATOR_MODE_NORMAL:
	case REGULATOR_MODE_IDLE:
	case REGULATOR_MODE_STANDBY:
		break;
	default:
		rdev_err(rdev, "invalid mode %x specified\n", *mode);
		return -EINVAL;
	}

	if (!rdev->constraints) {
		rdev_err(rdev, "no constraints\n");
		return -ENODEV;
	}
	if (!(rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_MODE)) {
		rdev_err(rdev, "operation not allowed\n");
		return -EPERM;
	}

	/* The modes are bitmasks, the most power hungry modes having
	 * the lowest values. If the requested mode isn't supported
	 * try higher modes. */
	while (*mode) {
		if (rdev->constraints->valid_modes_mask & *mode)
			return 0;
		*mode /= 2;
	}

	return -EINVAL;
}

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 Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.