mac80211: properly deal with station hashtable insert errors

[ Upstream commit 62b14b241ca6f790a17ccd9dd9f62ce1b006d406 ]

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.

Cc: stable@vger.kernel.org
Fixes: 7bedd0cfad4e1 ("mac80211: use rhashtable for station table")
Reported-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index 2880f2ae99abe3a05b6421f53340a42e11a9ca30..a7027190f2984030a4b74ac7cb263632b7dd16c8 100644 (file)
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -252,11 +252,11 @@ void sta_info_free(struct ieee80211_local *local, struct sta_info *sta)
 }
 
 /* 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)
@@ -491,7 +491,9 @@ static int sta_info_insert_finish(struct sta_info *sta) __acquires(RCU)
        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);
 
@@ -526,6 +528,7 @@ static int sta_info_insert_finish(struct sta_info *sta) __acquires(RCU)
  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);