mac80211: fix deadlock with multiple interfaces

The locking around ieee80211_recalc_smps is
buggy -- it cannot acquire another interface's
mutex while the iflist mutex is held because
another code path could be holding the iface
mutex and trying to acquire the iflist mutex.

But the locking is also unnecessary, we only
check "ifmgd->associated" as a bool, and don't
use the pointer (in check_mgd_smps).

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

1 files changed, 1 insertions, 1 deletions

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index c37086a12f51..2b2982782bcd 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -913,7 +913,7 @@ static void ieee80211_set_associated(struct ieee80211_sub_if_data *sdata,
 
         mutex_lock(&local->iflist_mtx);
         ieee80211_recalc_ps(local, -1);
-        ieee80211_recalc_smps(local, sdata);
+        ieee80211_recalc_smps(local);
         mutex_unlock(&local->iflist_mtx);
 
         netif_tx_start_all_queues(sdata->dev);