mac80211: fix another key non-race

The code here is only not racy because all the
places that assign the pointers it uses are
holding the sta_mtx as well as the key_mtx and
so can't race against this because this code
holds the sta_mtx. But that's not intuitive,
so fix it to hold the key_mtx.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index f05244dc773..cba8309e9ac 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -652,10 +652,12 @@ static int __must_check __sta_info_destroy(struct sta_info *sta)
         if (ret)
                 return ret;
 
+        mutex_lock(&local->key_mtx);
         for (i = 0; i < NUM_DEFAULT_KEYS; i++)
-                ieee80211_key_free(local, sta->gtk[i]);
+                __ieee80211_key_free(sta->gtk[i]);
         if (sta->ptk)
-                ieee80211_key_free(local, sta->ptk);
+                __ieee80211_key_free(sta->ptk);
+        mutex_unlock(&local->key_mtx);
 
         sta->dead = true;