mac80211: don't inspect Sequence Control field on control frames

Per IEEE Std. 802.11-2012, Sec 8.2.4.4.1, the sequence Control field is
not present in control frames.  We noticed this problem when processing
Block Ack Requests.

Cc: stable@vger.kernel.org
Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: Javier Lopez <jlopex@cozybit.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index f73e0dda0d86..c6865f2f47f8 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1462,6 +1462,10 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
 
         hdr = (struct ieee80211_hdr *)rx->skb->data;
         fc = hdr->frame_control;
+
+        if (ieee80211_is_ctl(fc))
+                return RX_CONTINUE;
+
         sc = le16_to_cpu(hdr->seq_ctrl);
         frag = sc & IEEE80211_SCTL_FRAG;