mac80211: count interfaces correctly for combination checks

Since moving the interface combination checks to mac80211, it's
broken because it now only considers interfaces with an assigned
channel context, so for example any interface that isn't active
can still be up, which is clearly an issue; also, in particular
P2P-Device wdevs are an issue since they never have a chanctx.

Fix this by counting running interfaces instead the ones with a
channel context assigned.

Cc: stable@vger.kernel.org [3.16+]
Fixes: 73de86a38962b ("cfg80211/mac80211: move interface counting for combination check to mac80211")
Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
[rewrite commit message, dig out the commit it fixes]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 8428f4a954795657a32a24f77a0f9c9ae6591b7e..747bdcf72e92788574ec3e2e635b5e6b96cb75f0 100644 (file)
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -3178,7 +3178,7 @@ int ieee80211_check_combinations(struct ieee80211_sub_if_data *sdata,
                wdev_iter = &sdata_iter->wdev;
 
                if (sdata_iter == sdata ||
-                   rcu_access_pointer(sdata_iter->vif.chanctx_conf) == NULL ||
+                   !ieee80211_sdata_running(sdata_iter) ||
                    local->hw.wiphy->software_iftypes & BIT(wdev_iter->iftype))
                        continue;