mac80211: use del_timer_sync for final sta cleanup timer deletion

commit a56f992cdabc63f56b4b142885deebebf936ff76 upstream.

This is a very old bug, but there's nothing that prevents the
timer from running while the module is being removed when we
only do del_timer() instead of del_timer_sync().

The timer should normally not be running at this point, but
it's not clearly impossible (or we could just remove this.)

Tested-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index 6d25d7796fc6c53f75c9089d2212d06d365f363c..e2e0e0bc66224c652b338daccb166d7f1a485baa 100644 (file)
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -844,7 +844,7 @@ void sta_info_init(struct ieee80211_local *local)
 
 void sta_info_stop(struct ieee80211_local *local)
 {
-       del_timer(&local->sta_cleanup);
+       del_timer_sync(&local->sta_cleanup);
        sta_info_flush(local, NULL);
 }