mac80211: TDLS: always downgrade invalid chandefs

BugLink: https://bugs.launchpad.net/bugs/1878232

commit db8d9977 upstream.

Even if the current chandef width is equal to the station's max-BW, it
doesn't mean it's a valid width for TDLS. Make sure to always check
regulatory constraints in these cases.

Fixes: 0fabfaaf ("mac80211: upgrade BW of TDLS peers when possible")
Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ian May <ian.may@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

net/mac80211/tdls.c

@@ -332,7 +332,7 @@ ieee80211_tdls_chandef_vht_upgrade(struct ieee80211_sub_if_data *sdata,
 		return;
 
 	/* proceed to downgrade the chandef until usable or the same */
-	while (uc.width > max_width &&
+	while (uc.width > max_width ||
 	       !cfg80211_reg_can_beacon_relax(sdata->local->hw.wiphy, &uc,
 					      sdata->wdev.iftype))
 		ieee80211_chandef_downgrade(&uc);