From c09c4f31998bac6d73508e38812518aceb069b68 Mon Sep 17 00:00:00 2001 From: Ayala Beker Date: Wed, 20 Sep 2023 21:25:14 +0300 Subject: [PATCH] wifi: mac80211: don't connect to an AP while it's in a CSA process Connection to an AP that is running a CSA flow may end up with a failure as the AP might change its channel during the connection flow while we do not track the channel change yet. Avoid that by rejecting a connection to such an AP. Signed-off-by: Ayala Beker Signed-off-by: Gregory Greenman Link: https://lore.kernel.org/r/20230920211508.e5001a762a4a.I9745c695f3403b259ad000ce94110588a836c04a@changeid Signed-off-by: Johannes Berg --- net/mac80211/mlme.c | 34 +++++++++++++++++++++++++++++++++- 1 file changed, 33 insertions(+), 1 deletion(-) diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index a211f594f25a..a85873f305bf 100644 --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -7015,6 +7015,7 @@ int ieee80211_mgd_auth(struct ieee80211_sub_if_data *sdata, struct ieee80211_if_managed *ifmgd = &sdata->u.mgd; struct ieee80211_mgd_auth_data *auth_data; struct ieee80211_link_data *link; + const struct element *csa_elem, *ecsa_elem; u16 auth_alg; int err; bool cont_auth; @@ -7057,6 +7058,22 @@ int ieee80211_mgd_auth(struct ieee80211_sub_if_data *sdata, if (ifmgd->assoc_data) return -EBUSY; + rcu_read_lock(); + csa_elem = ieee80211_bss_get_elem(req->bss, WLAN_EID_CHANNEL_SWITCH); + ecsa_elem = ieee80211_bss_get_elem(req->bss, + WLAN_EID_EXT_CHANSWITCH_ANN); + if ((csa_elem && + csa_elem->datalen == sizeof(struct ieee80211_channel_sw_ie) && + ((struct ieee80211_channel_sw_ie *)csa_elem->data)->count != 0) || + (ecsa_elem && + ecsa_elem->datalen == sizeof(struct ieee80211_ext_chansw_ie) && + ((struct ieee80211_ext_chansw_ie *)ecsa_elem->data)->count != 0)) { + rcu_read_unlock(); + sdata_info(sdata, "AP is in CSA process, reject auth\n"); + return -EINVAL; + } + rcu_read_unlock(); + auth_data = kzalloc(sizeof(*auth_data) + req->auth_data_len + req->ie_len, GFP_KERNEL); if (!auth_data) @@ -7364,7 +7381,7 @@ int ieee80211_mgd_assoc(struct ieee80211_sub_if_data *sdata, struct ieee80211_local *local = sdata->local; struct ieee80211_if_managed *ifmgd = &sdata->u.mgd; struct ieee80211_mgd_assoc_data *assoc_data; - const struct element *ssid_elem; + const struct element *ssid_elem, *csa_elem, *ecsa_elem; struct ieee80211_vif_cfg *vif_cfg = &sdata->vif.cfg; ieee80211_conn_flags_t conn_flags = 0; struct ieee80211_link_data *link; @@ -7394,6 +7411,21 @@ int ieee80211_mgd_assoc(struct ieee80211_sub_if_data *sdata, kfree(assoc_data); return -EINVAL; } + + csa_elem = ieee80211_bss_get_elem(cbss, WLAN_EID_CHANNEL_SWITCH); + ecsa_elem = ieee80211_bss_get_elem(cbss, WLAN_EID_EXT_CHANSWITCH_ANN); + if ((csa_elem && + csa_elem->datalen == sizeof(struct ieee80211_channel_sw_ie) && + ((struct ieee80211_channel_sw_ie *)csa_elem->data)->count != 0) || + (ecsa_elem && + ecsa_elem->datalen == sizeof(struct ieee80211_ext_chansw_ie) && + ((struct ieee80211_ext_chansw_ie *)ecsa_elem->data)->count != 0)) { + sdata_info(sdata, "AP is in CSA process, reject assoc\n"); + rcu_read_unlock(); + kfree(assoc_data); + return -EINVAL; + } + memcpy(assoc_data->ssid, ssid_elem->data, ssid_elem->datalen); assoc_data->ssid_len = ssid_elem->datalen; memcpy(vif_cfg->ssid, assoc_data->ssid, assoc_data->ssid_len);