From 3b3ec3d52e8f72ec8c40477b96f23440a89000be Mon Sep 17 00:00:00 2001 From: Shaul Triebitz Date: Thu, 28 May 2020 21:34:37 +0200 Subject: mac80211: check the correct bit for EMA AP An AP supporting EMA (Enhanced Multi-BSSID advertisement) should set bit 83 in the extended capabilities IE (9.4.2.26 in the 802.11ax D5 spec). So the *3rd* bit of the 10th byte should be checked. Also, in one place, the wrong byte was checked. (cfg80211_find_ie returns a pointer to the beginning of the IE, so the data really starts at ie[2], so the 10th byte should be ie[12]. To avoid this confusion, use cfg80211_find_elem instead). Signed-off-by: Shaul Triebitz Link: https://lore.kernel.org/r/20200528213443.4316121fa2a3.I9745582f8d41ad8e689dac0fefcd70b276d7c1ea@changeid Signed-off-by: Johannes Berg --- net/mac80211/mlme.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) (limited to 'net/mac80211') diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index bc558d1d20fc..c534cd1bb9cd 100644 --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -5596,7 +5596,7 @@ int ieee80211_mgd_assoc(struct ieee80211_sub_if_data *sdata, assoc_data->timeout_started = true; assoc_data->need_beacon = true; } else if (beacon_ies) { - const u8 *ie; + const struct element *elem; u8 dtim_count = 0; ieee80211_get_dtim(beacon_ies, &dtim_count, @@ -5613,15 +5613,15 @@ int ieee80211_mgd_assoc(struct ieee80211_sub_if_data *sdata, sdata->vif.bss_conf.sync_dtim_count = dtim_count; } - ie = cfg80211_find_ext_ie(WLAN_EID_EXT_MULTIPLE_BSSID_CONFIGURATION, - beacon_ies->data, beacon_ies->len); - if (ie && ie[1] >= 3) - sdata->vif.bss_conf.profile_periodicity = ie[4]; + elem = cfg80211_find_ext_elem(WLAN_EID_EXT_MULTIPLE_BSSID_CONFIGURATION, + beacon_ies->data, beacon_ies->len); + if (elem && elem->datalen >= 3) + sdata->vif.bss_conf.profile_periodicity = elem->data[2]; - ie = cfg80211_find_ie(WLAN_EID_EXT_CAPABILITY, - beacon_ies->data, beacon_ies->len); - if (ie && ie[1] >= 11 && - (ie[10] & WLAN_EXT_CAPA11_EMA_SUPPORT)) + elem = cfg80211_find_elem(WLAN_EID_EXT_CAPABILITY, + beacon_ies->data, beacon_ies->len); + if (elem && elem->datalen >= 11 && + (elem->data[10] & WLAN_EXT_CAPA11_EMA_SUPPORT)) sdata->vif.bss_conf.ema_ap = true; } else { assoc_data->timeout = jiffies; -- cgit v1.2.3