static int cqspi_setup_flash(struct cqspi_st *cqspi, struct device_node *np)
{
	struct platform_device *pdev = cqspi->pdev;
	struct device *dev = &pdev->dev;
	struct cqspi_flash_pdata *f_pdata;
	struct spi_nor *nor;
	struct mtd_info *mtd;
	unsigned int cs;
	int i, ret;

	/* Get flash device data */
	for_each_available_child_of_node(dev->of_node, np) {
		if (of_property_read_u32(np, "reg", &cs)) {
			dev_err(dev, "Couldn't determine chip select.\n");
 			goto err;
 		}
 
		if (cs > CQSPI_MAX_CHIPSELECT) {
 			dev_err(dev, "Chip select %d out of range.\n", cs);
 			goto err;
 		}

		f_pdata = &cqspi->f_pdata[cs];
		f_pdata->cqspi = cqspi;
		f_pdata->cs = cs;

		ret = cqspi_of_get_flash_pdata(pdev, f_pdata, np);
		if (ret)
			goto err;

		nor = &f_pdata->nor;
		mtd = &nor->mtd;

		mtd->priv = nor;

		nor->dev = dev;
		spi_nor_set_flash_node(nor, np);
		nor->priv = f_pdata;

		nor->read_reg = cqspi_read_reg;
		nor->write_reg = cqspi_write_reg;
		nor->read = cqspi_read;
		nor->write = cqspi_write;
		nor->erase = cqspi_erase;
		nor->prepare = cqspi_prep;
		nor->unprepare = cqspi_unprep;

		mtd->name = devm_kasprintf(dev, GFP_KERNEL, "%s.%d",
					   dev_name(dev), cs);
		if (!mtd->name) {
			ret = -ENOMEM;
			goto err;
		}

		ret = spi_nor_scan(nor, NULL, SPI_NOR_QUAD);
		if (ret)
			goto err;

		ret = mtd_device_register(mtd, NULL, 0);
		if (ret)
			goto err;

		f_pdata->registered = true;
	}

	return 0;

err:
	for (i = 0; i < CQSPI_MAX_CHIPSELECT; i++)
		if (cqspi->f_pdata[i].registered)
			mtd_device_unregister(&cqspi->f_pdata[i].nor.mtd);
	return ret;
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.