static int brcmf_enable_bw40_2g(struct brcmf_cfg80211_info *cfg)
{
	struct brcmf_if *ifp = netdev_priv(cfg_to_ndev(cfg));
	struct ieee80211_supported_band *band;
	struct brcmf_fil_bwcap_le band_bwcap;
	struct brcmf_chanspec_list *list;
	u8 *pbuf;
	u32 val;
	int err;
	struct brcmu_chan ch;
	u32 num_chan;
	int i, j;

	/* verify support for bw_cap command */
	val = WLC_BAND_5G;
	err = brcmf_fil_iovar_int_get(ifp, "bw_cap", &val);

	if (!err) {
		/* only set 2G bandwidth using bw_cap command */
		band_bwcap.band = cpu_to_le32(WLC_BAND_2G);
		band_bwcap.bw_cap = cpu_to_le32(WLC_BW_CAP_40MHZ);
		err = brcmf_fil_iovar_data_set(ifp, "bw_cap", &band_bwcap,
					       sizeof(band_bwcap));
	} else {
		brcmf_dbg(INFO, "fallback to mimo_bw_cap\n");
		val = WLC_N_BW_40ALL;
		err = brcmf_fil_iovar_int_set(ifp, "mimo_bw_cap", val);
	}

	if (!err) {
		/* update channel info in 2G band */
		pbuf = kzalloc(BRCMF_DCMD_MEDLEN, GFP_KERNEL);

		if (pbuf == NULL)
			return -ENOMEM;

		ch.band = BRCMU_CHAN_BAND_2G;
		ch.bw = BRCMU_CHAN_BW_40;
		ch.sb = BRCMU_CHAN_SB_NONE;
		ch.chnum = 0;
		cfg->d11inf.encchspec(&ch);

		/* pass encoded chanspec in query */
		*(__le16 *)pbuf = cpu_to_le16(ch.chspec);

		err = brcmf_fil_iovar_data_get(ifp, "chanspecs", pbuf,
					       BRCMF_DCMD_MEDLEN);
		if (err) {
			brcmf_err("get chanspecs error (%d)\n", err);
			kfree(pbuf);
			return err;
		}

		band = cfg_to_wiphy(cfg)->bands[NL80211_BAND_2GHZ];
		list = (struct brcmf_chanspec_list *)pbuf;
		num_chan = le32_to_cpu(list->count);
		for (i = 0; i < num_chan; i++) {
			ch.chspec = (u16)le32_to_cpu(list->element[i]);
			cfg->d11inf.decchspec(&ch);
			if (WARN_ON(ch.band != BRCMU_CHAN_BAND_2G))
				continue;
			if (WARN_ON(ch.bw != BRCMU_CHAN_BW_40))
				continue;
			for (j = 0; j < band->n_channels; j++) {
				if (band->channels[j].hw_value == ch.control_ch_num)
					break;
			}
			if (WARN_ON(j == band->n_channels))
				continue;

			brcmf_update_bw40_channel_flag(&band->channels[j], &ch);
		}
		kfree(pbuf);
	}
	return err;
}

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.