wifi: mac80211: Fix 6 GHz Band capabilities element advertisement in lower bands

Currently, when adding the 6 GHz Band Capabilities element, the channel
list of the wiphy is checked to determine if 6 GHz is supported for a given
virtual interface. However, in a multi-radio wiphy (e.g., one that has
both lower bands and 6 GHz combined), the wiphy advertises support for
all bands. As a result, the 6 GHz Band Capabilities element is incorrectly
included in mesh beacon and station's association request frames of
interfaces operating in lower bands, without verifying whether the
interface is actually operating in a 6 GHz channel.

Fix this by verifying if the interface operates on 6 GHz channel
before adding the element. Note that this check cannot be placed
directly in ieee80211_put_he_6ghz_cap() as the same function is used to
add probe request elements while initiating scan in which case the
interface may not be operating in any band's channel.

Signed-off-by: Ramya Gnanasekar <[email protected]>
Signed-off-by: Rameshkumar Sundaram <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Johannes Berg <[email protected]>

Author: Ramya Gnanasekar

net/mac80211/mesh.c

@@ -624,6 +624,9 @@ int mesh_add_he_6ghz_cap_ie(struct ieee80211_sub_if_data *sdata,
 	if (!sband)
 		return -EINVAL;
 
+	if (sband->band != NL80211_BAND_6GHZ)
+		return 0;
+
 	iftd = ieee80211_get_sband_iftype_data(sband,
 					       NL80211_IFTYPE_MESH_POINT);
 	/* The device doesn't support HE in mesh mode or at all */

net/mac80211/mlme.c

@@ -1842,7 +1842,8 @@ ieee80211_add_link_elems(struct ieee80211_sub_if_data *sdata,
 		ieee80211_put_he_cap(skb, sdata, sband,
 				     &assoc_data->link[link_id].conn);
 		ADD_PRESENT_EXT_ELEM(WLAN_EID_EXT_HE_CAPABILITY);
-		ieee80211_put_he_6ghz_cap(skb, sdata, smps_mode);
+		if (sband->band == NL80211_BAND_6GHZ)
+			ieee80211_put_he_6ghz_cap(skb, sdata, smps_mode);
 	}
 
 	/*