static int tg3_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
	struct mii_ioctl_data *data = if_mii(ifr);
	struct tg3 *tp = netdev_priv(dev);
	int err;

	if (tg3_flag(tp, USE_PHYLIB)) {
		struct phy_device *phydev;
		if (!(tp->phy_flags & TG3_PHYFLG_IS_CONNECTED))
			return -EAGAIN;
		phydev = tp->mdio_bus->phy_map[TG3_PHY_MII_ADDR];
		return phy_mii_ioctl(phydev, ifr, cmd);
	}

	switch (cmd) {
	case SIOCGMIIPHY:
		data->phy_id = tp->phy_addr;

		/* fallthru */
	case SIOCGMIIREG: {
		u32 mii_regval;

		if (tp->phy_flags & TG3_PHYFLG_PHY_SERDES)
			break;			/* We have no PHY */

		if (!netif_running(dev))
			return -EAGAIN;

		spin_lock_bh(&tp->lock);
		err = __tg3_readphy(tp, data->phy_id & 0x1f,
				    data->reg_num & 0x1f, &mii_regval);
		spin_unlock_bh(&tp->lock);

		data->val_out = mii_regval;

		return err;
	}

	case SIOCSMIIREG:
		if (tp->phy_flags & TG3_PHYFLG_PHY_SERDES)
			break;			/* We have no PHY */

		if (!netif_running(dev))
			return -EAGAIN;

		spin_lock_bh(&tp->lock);
		err = __tg3_writephy(tp, data->phy_id & 0x1f,
				     data->reg_num & 0x1f, data->val_in);
		spin_unlock_bh(&tp->lock);

		return err;

	case SIOCSHWTSTAMP:
		return tg3_hwtstamp_ioctl(dev, ifr, cmd);

	default:
		/* do nothing */
		break;
	}
	return -EOPNOTSUPP;
}

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.