mac80211: don't look at the PM bit of BAR frames

When a peer sends a BAR frame with PM bit clear, we should
not modify its PM state as madated by the spec in
802.11-20012 10.2.1.2.

Cc: stable@vger.kernel.org
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 1f75280ba26c..3674fe3d67dc 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1613,12 +1613,16 @@ ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
          */
         if (!ieee80211_hw_check(&sta->local->hw, AP_LINK_PS) &&
             !ieee80211_has_morefrags(hdr->frame_control) &&
+            !ieee80211_is_back_req(hdr->frame_control) &&
             !(status->rx_flags & IEEE80211_RX_DEFERRED_RELEASE) &&
             (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
              rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
-            /* PM bit is only checked in frames where it isn't reserved,
+            /*
+             * PM bit is only checked in frames where it isn't reserved,
              * in AP mode it's reserved in non-bufferable management frames
              * (cf. IEEE 802.11-2012 8.2.4.1.7 Power Management field)
+             * BAR frames should be ignored as specified in
+             * IEEE 802.11-2012 10.2.1.2.
              */
             (!ieee80211_is_mgmt(hdr->frame_control) ||
              ieee80211_is_bufferable_mmpdu(hdr->frame_control))) {