[PATCH 4.9 07/60] mac80211: dont look at the PM bit of BAR frames

From: Greg Kroah-Hartman
Date: Mon Jun 19 2017 - 11:29:06 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx>

commit 769dc04db3ed8484798aceb015b94deacc2ba557 upstream.

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.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx>
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
net/mac80211/rx.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1585,12 +1585,16 @@ ieee80211_rx_h_sta_process(struct ieee80
*/
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))) {