cfg80211: disallow more station changes

The following changes are invalid and should be
disallowed when a station already exists:
 * supported rates changes, except for TDLS peers
 * listen interval changes
 * HT capability changes

Disallow them and also update a mac80211 comment
explaining how they would be racy.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 5 insertions, 4 deletions

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index f4d12c71928d..7d290bce0927 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -1208,10 +1208,11 @@ static int sta_apply_parameters(struct ieee80211_local *local,
                 sta->sta.aid = params->aid;
 
         /*
-         * FIXME: updating the following information is racy when this
-         *        function is called from ieee80211_change_station().
-         *        However, all this information should be static so
-         *        maybe we should just reject attemps to change it.
+         * Some of the following updates would be racy if called on an
+         * existing station, via ieee80211_change_station(). However,
+         * all such changes are rejected by cfg80211 except for updates
+         * changing the supported rates on an existing but not yet used
+         * TDLS peer.
          */
 
         if (params->listen_interval >= 0)