mii_read (struct net_device *dev, int phy_addr, int reg_num)
{
	u32 cmd;
	int i;
	u32 retval = 0;

	/* Preamble */
	mii_send_bits (dev, 0xffffffff, 32);
	/* ST(2), OP(2), ADDR(5), REG#(5), TA(2), Data(16) total 32 bits */
	/* ST,OP = 0110'b for read operation */
	cmd = (0x06 << 10 | phy_addr << 5 | reg_num);
	mii_send_bits (dev, cmd, 14);
	/* Turnaround */
	if (mii_getbit (dev))
		goto err_out;
	/* Read data */
	for (i = 0; i < 16; i++) {
		retval |= mii_getbit (dev);
		retval <<= 1;
	}
	/* End cycle */
	mii_getbit (dev);
	return (retval >> 1) & 0xffff;

      err_out:
	return 0;
}

This category addresses vulnerabilities caused by flawed access control mechanisms, where incorrect permission settings allow unauthorized users to access restricted resources.