static int cqspi_command_write(struct spi_nor *nor, const u8 opcode,
			       const u8 *txbuf, const unsigned n_tx)
{
	struct cqspi_flash_pdata *f_pdata = nor->priv;
	struct cqspi_st *cqspi = f_pdata->cqspi;
	void __iomem *reg_base = cqspi->iobase;
	unsigned int reg;
	unsigned int data;
	int ret;

	if (n_tx > 4 || (n_tx && !txbuf)) {
		dev_err(nor->dev,
			"Invalid input argument, cmdlen %d txbuf 0x%p\n",
			n_tx, txbuf);
		return -EINVAL;
	}

	reg = opcode << CQSPI_REG_CMDCTRL_OPCODE_LSB;
	if (n_tx) {
		reg |= (0x1 << CQSPI_REG_CMDCTRL_WR_EN_LSB);
		reg |= ((n_tx - 1) & CQSPI_REG_CMDCTRL_WR_BYTES_MASK)
			<< CQSPI_REG_CMDCTRL_WR_BYTES_LSB;
		data = 0;
		memcpy(&data, txbuf, n_tx);
		writel(data, reg_base + CQSPI_REG_CMDWRITEDATALOWER);
	}

	ret = cqspi_exec_flash_cmd(cqspi, reg);
	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.