static int lbs_process_bss(struct bss_descriptor *bss,
			   uint8_t **pbeaconinfo, int *bytesleft)
{
	struct ieeetypes_fhparamset *pFH;
	struct ieeetypes_dsparamset *pDS;
	struct ieeetypes_cfparamset *pCF;
	struct ieeetypes_ibssparamset *pibss;
	DECLARE_MAC_BUF(mac);
	struct ieeetypes_countryinfoset *pcountryinfo;
	uint8_t *pos, *end, *p;
	uint8_t n_ex_rates = 0, got_basic_rates = 0, n_basic_rates = 0;
	uint16_t beaconsize = 0;
	int ret;

	lbs_deb_enter(LBS_DEB_SCAN);

	if (*bytesleft >= sizeof(beaconsize)) {
		/* Extract & convert beacon size from the command buffer */
		beaconsize = get_unaligned_le16(*pbeaconinfo);
		*bytesleft -= sizeof(beaconsize);
		*pbeaconinfo += sizeof(beaconsize);
	}

	if (beaconsize == 0 || beaconsize > *bytesleft) {
		*pbeaconinfo += *bytesleft;
		*bytesleft = 0;
		ret = -1;
		goto done;
	}

	/* Initialize the current working beacon pointer for this BSS iteration */
	pos = *pbeaconinfo;
	end = pos + beaconsize;

	/* Advance the return beacon pointer past the current beacon */
	*pbeaconinfo += beaconsize;
	*bytesleft -= beaconsize;

	memcpy(bss->bssid, pos, ETH_ALEN);
	lbs_deb_scan("process_bss: BSSID %s\n", print_mac(mac, bss->bssid));
	pos += ETH_ALEN;

	if ((end - pos) < 12) {
		lbs_deb_scan("process_bss: Not enough bytes left\n");
		ret = -1;
		goto done;
	}

	/*
	 * next 4 fields are RSSI, time stamp, beacon interval,
	 *   and capability information
	 */

	/* RSSI is 1 byte long */
	bss->rssi = *pos;
	lbs_deb_scan("process_bss: RSSI %d\n", *pos);
	pos++;

	/* time stamp is 8 bytes long */
	pos += 8;

	/* beacon interval is 2 bytes long */
	bss->beaconperiod = get_unaligned_le16(pos);
	pos += 2;

	/* capability information is 2 bytes long */
	bss->capability = get_unaligned_le16(pos);
	lbs_deb_scan("process_bss: capabilities 0x%04x\n", bss->capability);
	pos += 2;

	if (bss->capability & WLAN_CAPABILITY_PRIVACY)
		lbs_deb_scan("process_bss: WEP enabled\n");
	if (bss->capability & WLAN_CAPABILITY_IBSS)
		bss->mode = IW_MODE_ADHOC;
	else
		bss->mode = IW_MODE_INFRA;

	/* rest of the current buffer are IE's */
	lbs_deb_scan("process_bss: IE len %zd\n", end - pos);
	lbs_deb_hex(LBS_DEB_SCAN, "process_bss: IE info", pos, end - pos);

	/* process variable IE */
	while (pos <= end - 2) {
		struct ieee80211_info_element * elem = (void *)pos;

		if (pos + elem->len > end) {
			lbs_deb_scan("process_bss: error in processing IE, "
				     "bytes left < IE length\n");
			break;
		}

		switch (elem->id) {
		case MFIE_TYPE_SSID:
			bss->ssid_len = elem->len;
			memcpy(bss->ssid, elem->data, elem->len);
			lbs_deb_scan("got SSID IE: '%s', len %u\n",
			             escape_essid(bss->ssid, bss->ssid_len),
			             bss->ssid_len);
			break;

		case MFIE_TYPE_RATES:
			n_basic_rates = min_t(uint8_t, MAX_RATES, elem->len);
			memcpy(bss->rates, elem->data, n_basic_rates);
			got_basic_rates = 1;
			lbs_deb_scan("got RATES IE\n");
			break;

		case MFIE_TYPE_FH_SET:
			pFH = (struct ieeetypes_fhparamset *) pos;
			memmove(&bss->phyparamset.fhparamset, pFH,
				sizeof(struct ieeetypes_fhparamset));
			lbs_deb_scan("got FH IE\n");
			break;

		case MFIE_TYPE_DS_SET:
			pDS = (struct ieeetypes_dsparamset *) pos;
			bss->channel = pDS->currentchan;
			memcpy(&bss->phyparamset.dsparamset, pDS,
			       sizeof(struct ieeetypes_dsparamset));
			lbs_deb_scan("got DS IE, channel %d\n", bss->channel);
			break;

		case MFIE_TYPE_CF_SET:
			pCF = (struct ieeetypes_cfparamset *) pos;
			memcpy(&bss->ssparamset.cfparamset, pCF,
			       sizeof(struct ieeetypes_cfparamset));
			lbs_deb_scan("got CF IE\n");
			break;

		case MFIE_TYPE_IBSS_SET:
			pibss = (struct ieeetypes_ibssparamset *) pos;
			bss->atimwindow = le16_to_cpu(pibss->atimwindow);
			memmove(&bss->ssparamset.ibssparamset, pibss,
				sizeof(struct ieeetypes_ibssparamset));
			lbs_deb_scan("got IBSS IE\n");
			break;

		case MFIE_TYPE_COUNTRY:
			pcountryinfo = (struct ieeetypes_countryinfoset *) pos;
			lbs_deb_scan("got COUNTRY IE\n");
			if (pcountryinfo->len < sizeof(pcountryinfo->countrycode)
			    || pcountryinfo->len > 254) {
				lbs_deb_scan("process_bss: 11D- Err CountryInfo len %d, min %zd, max 254\n",
					     pcountryinfo->len, sizeof(pcountryinfo->countrycode));
				ret = -1;
				goto done;
			}

			memcpy(&bss->countryinfo, pcountryinfo, pcountryinfo->len + 2);
			lbs_deb_hex(LBS_DEB_SCAN, "process_bss: 11d countryinfo",
				    (uint8_t *) pcountryinfo,
				    (int) (pcountryinfo->len + 2));
			break;

		case MFIE_TYPE_RATES_EX:
			/* only process extended supported rate if data rate is
			 * already found. Data rate IE should come before
			 * extended supported rate IE
			 */
			lbs_deb_scan("got RATESEX IE\n");
			if (!got_basic_rates) {
				lbs_deb_scan("... but ignoring it\n");
				break;
			}

			n_ex_rates = elem->len;
			if (n_basic_rates + n_ex_rates > MAX_RATES)
				n_ex_rates = MAX_RATES - n_basic_rates;

			p = bss->rates + n_basic_rates;
			memcpy(p, elem->data, n_ex_rates);
			break;

		case MFIE_TYPE_GENERIC:
			if (elem->len >= 4 &&
			    elem->data[0] == 0x00 && elem->data[1] == 0x50 &&
			    elem->data[2] == 0xf2 && elem->data[3] == 0x01) {
				bss->wpa_ie_len = min(elem->len + 2, MAX_WPA_IE_LEN);
				memcpy(bss->wpa_ie, elem, bss->wpa_ie_len);
				lbs_deb_scan("got WPA IE\n");
				lbs_deb_hex(LBS_DEB_SCAN, "WPA IE", bss->wpa_ie, elem->len);
			} else if (elem->len >= MARVELL_MESH_IE_LENGTH &&
				   elem->data[0] == 0x00 && elem->data[1] == 0x50 &&
				   elem->data[2] == 0x43 && elem->data[3] == 0x04) {
				lbs_deb_scan("got mesh IE\n");
				bss->mesh = 1;
			} else {
				lbs_deb_scan("got generic IE: %02x:%02x:%02x:%02x, len %d\n",
					elem->data[0], elem->data[1],
					elem->data[2], elem->data[3],
					elem->len);
			}
			break;

		case MFIE_TYPE_RSN:
			lbs_deb_scan("got RSN IE\n");
			bss->rsn_ie_len = min(elem->len + 2, MAX_WPA_IE_LEN);
			memcpy(bss->rsn_ie, elem, bss->rsn_ie_len);
			lbs_deb_hex(LBS_DEB_SCAN, "process_bss: RSN_IE",
				    bss->rsn_ie, elem->len);
			break;

		default:
			lbs_deb_scan("got IE 0x%04x, len %d\n",
				     elem->id, elem->len);
			break;
		}

		pos += elem->len + 2;
	}

	/* Timestamp */
	bss->last_scanned = jiffies;
	lbs_unset_basic_rate_flags(bss->rates, sizeof(bss->rates));

	ret = 0;

done:
	lbs_deb_leave_args(LBS_DEB_SCAN, "ret %d", ret);
	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.