[PATCH 4.5 087/124] mac80211: properly deal with station hashtable insert errors

[Greg Kroah-Hartman]

4.5-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Johannes Berg <johannes.b...@intel.com>

commit 62b14b241ca6f790a17ccd9dd9f62ce1b006d406 upstream.

The original hand-implemented hash-table in mac80211 couldn't result
in insertion errors, and while converting to rhashtable I evidently
forgot to check the errors.

This surfaced now only because Ben is adding many identical keys and
that resulted in hidden insertion errors.

Fixes: 7bedd0cfad4e1 ("mac80211: use rhashtable for station table")
Reported-by: Ben Greear <gree...@candelatech.com>
Signed-off-by: Johannes Berg <johannes.b...@intel.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 net/mac80211/sta_info.c |   13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -257,11 +257,11 @@ void sta_info_free(struct ieee80211_loca
 }
 
 /* Caller must hold local->sta_mtx */
-static void sta_info_hash_add(struct ieee80211_local *local,
-                             struct sta_info *sta)
+static int sta_info_hash_add(struct ieee80211_local *local,
+                            struct sta_info *sta)
 {
-       rhashtable_insert_fast(&local->sta_hash, &sta->hash_node,
-                              sta_rht_params);
+       return rhashtable_insert_fast(&local->sta_hash, &sta->hash_node,
+                                     sta_rht_params);
 }
 
 static void sta_deliver_ps_frames(struct work_struct *wk)
@@ -517,7 +517,9 @@ static int sta_info_insert_finish(struct
        set_sta_flag(sta, WLAN_STA_BLOCK_BA);
 
        /* make the station visible */
-       sta_info_hash_add(local, sta);
+       err = sta_info_hash_add(local, sta);
+       if (err)
+               goto out_drop_sta;
 
        list_add_tail_rcu(&sta->list, &local->sta_list);
 
@@ -552,6 +554,7 @@ static int sta_info_insert_finish(struct
  out_remove:
        sta_info_hash_del(local, sta);
        list_del_rcu(&sta->list);
+ out_drop_sta:
        local->num_sta--;
        synchronize_net();
        __cleanup_single_sta(sta);