releases/2.6.32.17/iwlagn-verify-flow-id-in-compressed-ba-packet.patch

   1 From b561e8274f75831ee87e4ea378cbb1f9f050a51a Mon Sep 17 00:00:00 2001
   2 From: Shanyu Zhao <shanyu.zhao@intel.com>
   3 Date: Tue, 1 Jun 2010 17:13:58 -0700
   4 Subject: iwlagn: verify flow id in compressed BA packet
   5
   6 From: Shanyu Zhao <shanyu.zhao@intel.com>
   7
   8 commit b561e8274f75831ee87e4ea378cbb1f9f050a51a upstream.
   9
  10 The flow id (scd_flow) in a compressed BA packet should match the txq_id
  11 of the queue from which the aggregated packets were sent. However, in
  12 some hardware like the 1000 series, sometimes the flow id is 0 for the
  13 txq_id (10 to 19). This can cause the annoying message:
  14 [ 2213.306191] iwlagn 0000:01:00.0: Received BA when not expected
  15 [ 2213.310178] iwlagn 0000:01:00.0: Read index for DMA queue txq id (0),
  16 index 5, is out of range [0-256] 7 7.
  17
  18 And even worse, if agg->wait_for_ba is true when the bad BA is arriving,
  19 this can cause system hang due to NULL pointer dereference because the
  20 code is operating in a wrong tx queue!
  21
  22 Signed-off-by: Shanyu Zhao <shanyu.zhao@intel.com>
  23 Signed-off-by: Pradeep Kulkarni <pradeepx.kulkarni@intel.com>
  24 Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
  25 Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
  26
  27 ---
  28  drivers/net/wireless/iwlwifi/iwl-tx.c |    5 +++++
  29  1 file changed, 5 insertions(+)
  30
  31 --- a/drivers/net/wireless/iwlwifi/iwl-tx.c
  32 +++ b/drivers/net/wireless/iwlwifi/iwl-tx.c
  33 @@ -1479,6 +1479,11 @@ void iwl_rx_reply_compressed_ba(struct i
  34         sta_id = ba_resp->sta_id;
  35         tid = ba_resp->tid;
  36         agg = &priv->stations[sta_id].tid[tid].agg;
  37 +       if (unlikely(agg->txq_id != scd_flow)) {
  38 +               IWL_ERR(priv, "BA scd_flow %d does not match txq_id %d\n",
  39 +                       scd_flow, agg->txq_id);
  40 +               return;
  41 +       }
  42
  43         /* Find index just before block-ack window */
  44         index = iwl_queue_dec_wrap(ba_resp_scd_ssn & 0xff, txq->q.n_bd);