static int tg3_setup_fiber_by_hand(struct tg3 *tp, u32 mac_status)
{
	int current_link_up = 0;

	if (!(mac_status & MAC_STATUS_PCS_SYNCED))
		goto out;

	if (tp->link_config.autoneg == AUTONEG_ENABLE) {
		u32 txflags, rxflags;
		int i;

		if (fiber_autoneg(tp, &txflags, &rxflags)) {
			u32 local_adv = 0, remote_adv = 0;

			if (txflags & ANEG_CFG_PS1)
				local_adv |= ADVERTISE_1000XPAUSE;
			if (txflags & ANEG_CFG_PS2)
				local_adv |= ADVERTISE_1000XPSE_ASYM;

			if (rxflags & MR_LP_ADV_SYM_PAUSE)
				remote_adv |= LPA_1000XPAUSE;
			if (rxflags & MR_LP_ADV_ASYM_PAUSE)
				remote_adv |= LPA_1000XPAUSE_ASYM;

			tp->link_config.rmt_adv =
					   mii_adv_to_ethtool_adv_x(remote_adv);

			tg3_setup_flow_control(tp, local_adv, remote_adv);

			current_link_up = 1;
		}
		for (i = 0; i < 30; i++) {
			udelay(20);
			tw32_f(MAC_STATUS,
			       (MAC_STATUS_SYNC_CHANGED |
				MAC_STATUS_CFG_CHANGED));
			udelay(40);
			if ((tr32(MAC_STATUS) &
			     (MAC_STATUS_SYNC_CHANGED |
			      MAC_STATUS_CFG_CHANGED)) == 0)
				break;
		}

		mac_status = tr32(MAC_STATUS);
		if (current_link_up == 0 &&
		    (mac_status & MAC_STATUS_PCS_SYNCED) &&
		    !(mac_status & MAC_STATUS_RCVD_CFG))
			current_link_up = 1;
	} else {
		tg3_setup_flow_control(tp, 0, 0);

		/* Forcing 1000FD link up. */
		current_link_up = 1;

		tw32_f(MAC_MODE, (tp->mac_mode | MAC_MODE_SEND_CONFIGS));
		udelay(40);

		tw32_f(MAC_MODE, tp->mac_mode);
		udelay(40);
	}

out:
	return current_link_up;
}

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.