wifi: mac80211: validate link address doesn't change

When modifying a link station, validate that the link address
doesn't change, except the first time the link is created.

Fixes: b95eb7f0eee4 ("wifi: cfg80211/mac80211: separate link params from station params")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index b0fdfc61b2f9db8a436d9c666950c29b7fd7e42d..fa4379761e12c0481cf72bfadf4bc025eff4ccb4 100644 (file)
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -1597,7 +1597,7 @@ static void sta_apply_mesh_params(struct ieee80211_local *local,
 }
 
 static int sta_link_apply_parameters(struct ieee80211_local *local,
-                                    struct sta_info *sta,
+                                    struct sta_info *sta, bool new_link,
                                     struct link_station_parameters *params)
 {
        int ret = 0;
@@ -1618,8 +1618,13 @@ static int sta_link_apply_parameters(struct ieee80211_local *local,
                return -EINVAL;
 
        if (params->link_mac) {
-               memcpy(link_sta->addr, params->link_mac, ETH_ALEN);
-               memcpy(link_sta->pub->addr, params->link_mac, ETH_ALEN);
+               if (new_link) {
+                       memcpy(link_sta->addr, params->link_mac, ETH_ALEN);
+                       memcpy(link_sta->pub->addr, params->link_mac, ETH_ALEN);
+               } else if (!ether_addr_equal(link_sta->addr,
+                                            params->link_mac)) {
+                       return -EINVAL;
+               }
        }
 
        if (params->txpwr_set) {
@@ -1797,7 +1802,8 @@ static int sta_apply_parameters(struct ieee80211_local *local,
        if (params->listen_interval >= 0)
                sta->listen_interval = params->listen_interval;
 
-       ret = sta_link_apply_parameters(local, sta, &params->link_sta_params);
+       ret = sta_link_apply_parameters(local, sta, false,
+                                       &params->link_sta_params);
        if (ret)
                return ret;
 
@@ -4650,7 +4656,7 @@ static int sta_add_link_station(struct ieee80211_local *local,
        if (ret)
                return ret;
 
-       ret = sta_link_apply_parameters(local, sta, params);
+       ret = sta_link_apply_parameters(local, sta, true, params);
        if (ret) {
                ieee80211_sta_free_link(sta, params->link_id);
                return ret;
@@ -4688,7 +4694,7 @@ static int sta_mod_link_station(struct ieee80211_local *local,
        if (!(sta->sta.valid_links & BIT(params->link_id)))
                return -EINVAL;
 
-       return sta_link_apply_parameters(local, sta, params);
+       return sta_link_apply_parameters(local, sta, false, params);
 }
 
 static int