mac80211: fix auth/assoc data & timer leak

When removing an interface while it is in the
process of authenticating or associating, we
leak the auth_data or assoc_data, and leave
the timer pending. The timer then crashes the
system when it fires as its data is gone.

Fix this by explicitly deleting all the data
when the interface is removed. This uncovered
another bug -- this problem should have been
detected by the sta_info_flush() warning but
that function doesn't ever return non-zero,
I'll fix that in a separate patch.

Reported-by: Hieu Nguyen <hieux.c.nguyen@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 1495fb99b379..0c220e1b6c9c 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -3513,6 +3513,19 @@ int ieee80211_mgd_disassoc(struct ieee80211_sub_if_data *sdata,
         return 0;
 }
 
+void ieee80211_mgd_teardown(struct ieee80211_sub_if_data *sdata)
+{
+        struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
+
+        mutex_lock(&ifmgd->mtx);
+        if (ifmgd->assoc_data)
+                ieee80211_destroy_assoc_data(sdata, false);
+        if (ifmgd->auth_data)
+                ieee80211_destroy_auth_data(sdata, false);
+        del_timer_sync(&ifmgd->timer);
+        mutex_unlock(&ifmgd->mtx);
+}
+
 void ieee80211_cqm_rssi_notify(struct ieee80211_vif *vif,
                                enum nl80211_cqm_rssi_threshold_event rssi_event,
                                gfp_t gfp)