mac80211: Fix possible race between sta_unblock and network softirq

All other code paths in sta_unblock synchronize with the network
softirq by using local_bh_disable/enable. Do the same around
ieee80211_sta_ps_deliver_wakeup.

Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.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 3c428d4839c7..ff11f6bf8266 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -238,9 +238,11 @@ static void sta_unblock(struct work_struct *wk)
         if (sta->dead)
                 return;
 
-        if (!test_sta_flag(sta, WLAN_STA_PS_STA))
+        if (!test_sta_flag(sta, WLAN_STA_PS_STA)) {
+                local_bh_disable();
                 ieee80211_sta_ps_deliver_wakeup(sta);
-        else if (test_and_clear_sta_flag(sta, WLAN_STA_PSPOLL)) {
+                local_bh_enable();
+        } else if (test_and_clear_sta_flag(sta, WLAN_STA_PSPOLL)) {
                 clear_sta_flag(sta, WLAN_STA_PS_DRIVER);
 
                 local_bh_disable();