mac80211: Do not override AID in the duration field

When updating the duration field for TX frames, skip the update for
PS-Poll frames that use this field for other purposes (AID).

Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 8f68bf9746d0..a910148b8228 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -872,6 +872,8 @@ ieee80211_tx_h_calculate_duration(struct ieee80211_tx_data *tx)
 
         do {
                 hdr = (void *) skb->data;
+                if (unlikely(ieee80211_is_pspoll(hdr->frame_control)))
+                        break; /* must not overwrite AID */
                 next_len = skb->next ? skb->next->len : 0;
                 group_addr = is_multicast_ether_addr(hdr->addr1);