mac80211: ignore NullFunc frames in the duplicate detection

commit 990d71846a0b7281bd933c34d734e6afc7408e7e upstream.

NullFunc packets should never be duplicate just like
QoS-NullFunc packets.

We saw a client that enters / exits power save with
NullFunc frames (and not with QoS-NullFunc) despite the
fact that the association supports HT.
This specific client also re-uses a non-zero sequence number
for different NullFunc frames.
At some point, the client had to send a retransmission of
the NullFunc frame and we dropped it, leading to a
misalignment in the power save state.
Fix this by never consider a NullFunc frame as duplicate,
just like we do for QoS NullFunc frames.

This fixes https://bugzilla.kernel.org/show_bug.cgi?id=201449

CC: <stable@vger.kernel.org>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 5ac7a0a499167e96be9e411fc72094d0a89dbfcc..5e2b4a41acf1490db160481c7366bd175b6a0900 100644 (file)
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1372,6 +1372,7 @@ ieee80211_rx_h_check_dup(struct ieee80211_rx_data *rx)
                return RX_CONTINUE;
 
        if (ieee80211_is_ctl(hdr->frame_control) ||
+           ieee80211_is_nullfunc(hdr->frame_control) ||
            ieee80211_is_qos_nullfunc(hdr->frame_control) ||
            is_multicast_ether_addr(hdr->addr1))
                return RX_CONTINUE;