mac80211: TDLS: don't require beaconing for AP BW

Stop downgrading TDLS chandef when reaching the AP BW. The AP provides
the necessary regulatory protection in this case.

This fixes https://bugzilla.kernel.org/show_bug.cgi?id=153961, which
reported an infinite loop here.

Reported-by: Kamil Toman <kamil.toman@gmail.com>
Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/mac80211/tdls.c b/net/mac80211/tdls.c
index b5d28f1..afca7d1 100644 (file)
--- a/net/mac80211/tdls.c
+++ b/net/mac80211/tdls.c
@@ -333,10 +333,11 @@ ieee80211_tdls_chandef_vht_upgrade(struct ieee80211_sub_if_data *sdata,
        if (!uc.center_freq1)
                return;
 
-       /* proceed to downgrade the chandef until usable or the same */
+       /* proceed to downgrade the chandef until usable or the same as AP BW */
        while (uc.width > max_width ||
-              !cfg80211_reg_can_beacon_relax(sdata->local->hw.wiphy, &uc,
-                                             sdata->wdev.iftype))
+              (uc.width > sta->tdls_chandef.width &&
+               !cfg80211_reg_can_beacon_relax(sdata->local->hw.wiphy, &uc,
+                                              sdata->wdev.iftype)))
                ieee80211_chandef_downgrade(&uc);
 
        if (!cfg80211_chandef_identical(&uc, &sta->tdls_chandef)) {