mac80211: handle drv_add_interface failures properly during reconfig

If any interface fails to be added to the driver in during reconfig,
we should remove all the successfully added interfaces and report
reconfig failure, so things can be cleaned up properly.  Failing to do
so can lead to subsequent failures and leave the drivers in a messed
up state.

Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index eec94447eef78bb589fd73e0826c6886bc3a2339..327886748a1d4e0699b91b843408d8f1fa15cac3 100644 (file)
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -1811,8 +1811,25 @@ int ieee80211_reconfig(struct ieee80211_local *local)
        list_for_each_entry(sdata, &local->interfaces, list) {
                if (sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
                    sdata->vif.type != NL80211_IFTYPE_MONITOR &&
-                   ieee80211_sdata_running(sdata))
+                   ieee80211_sdata_running(sdata)) {
                        res = drv_add_interface(local, sdata);
+                       if (WARN_ON(res))
+                               break;
+               }
+       }
+
+       /* If adding any of the interfaces failed above, roll back and
+        * report failure.
+        */
+       if (res) {
+               list_for_each_entry_continue_reverse(sdata, &local->interfaces,
+                                                    list)
+                       if (sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
+                           sdata->vif.type != NL80211_IFTYPE_MONITOR &&
+                           ieee80211_sdata_running(sdata))
+                               drv_remove_interface(local, sdata);
+               ieee80211_handle_reconfig_failure(local);
+               return res;
        }
 
        /* add channel contexts */