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, 8 insertions, 14 deletions

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 087f68ba6d7a..9bd8340af999 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -3188,13 +3188,9 @@ static int nl80211_set_station(struct sk_buff *skb, struct genl_info *info)
                         nla_len(info->attrs[NL80211_ATTR_STA_SUPPORTED_RATES]);
         }
 
-        if (info->attrs[NL80211_ATTR_STA_LISTEN_INTERVAL])
-                params.listen_interval =
-                    nla_get_u16(info->attrs[NL80211_ATTR_STA_LISTEN_INTERVAL]);
-
-        if (info->attrs[NL80211_ATTR_HT_CAPABILITY])
-                params.ht_capa =
-                        nla_data(info->attrs[NL80211_ATTR_HT_CAPABILITY]);
+        if (info->attrs[NL80211_ATTR_STA_LISTEN_INTERVAL] ||
+            info->attrs[NL80211_ATTR_HT_CAPABILITY])
+                return -EINVAL;
 
         if (!rdev->ops->change_station)
                 return -EOPNOTSUPP;
@@ -3246,6 +3242,10 @@ static int nl80211_set_station(struct sk_buff *skb, struct genl_info *info)
                                  BIT(NL80211_STA_FLAG_ASSOCIATED)))
                         return -EINVAL;
 
+                /* reject other things that can't change */
+                if (params.supported_rates)
+                        return -EINVAL;
+
                 /* must be last in here for error handling */
                 params.vlan = get_vlan(info, rdev);
                 if (IS_ERR(params.vlan))
@@ -3265,10 +3265,6 @@ static int nl80211_set_station(struct sk_buff *skb, struct genl_info *info)
                 /* disallow things sta doesn't support */
                 if (params.plink_action)
                         return -EINVAL;
-                if (params.ht_capa)
-                        return -EINVAL;
-                if (params.listen_interval >= 0)
-                        return -EINVAL;
                 /* reject any changes other than AUTHORIZED */
                 if (params.sta_flags_mask & ~BIT(NL80211_STA_FLAG_AUTHORIZED))
                         return -EINVAL;
@@ -3277,9 +3273,7 @@ static int nl80211_set_station(struct sk_buff *skb, struct genl_info *info)
                 /* disallow things mesh doesn't support */
                 if (params.vlan)
                         return -EINVAL;
-                if (params.ht_capa)
-                        return -EINVAL;
-                if (params.listen_interval >= 0)
+                if (params.supported_rates)
                         return -EINVAL;
                 /*
                  * No special handling for TDLS here -- the userspace