diff options
| author | Stanislaw Gruszka <sgruszka@redhat.com> | 2011-04-20 16:01:46 +0200 |
|---|---|---|
| committer | John W. Linville <linville@tuxdriver.com> | 2011-04-20 22:05:59 +0200 |
| commit | 069f40fc07f6df3da325e7ea1698a0d6247983d5 (patch) | |
| tree | 2717c5d0c0f1437e63b6d77565b1fd4dc39b13b2 | |
| parent | iwlwifi: fix skb usage after free (diff) | |
| download | linux-069f40fc07f6df3da325e7ea1698a0d6247983d5.tar.xz linux-069f40fc07f6df3da325e7ea1698a0d6247983d5.zip | |
iwl4965: fix skb usage after free
Since
commit a120e912eb51e347f36c71b60a1d13af74d30e83
Author: Stanislaw Gruszka <sgruszka@redhat.com>
Date: Fri Feb 19 15:47:33 2010 -0800
iwlwifi: sanity check before counting number of tfds can be free
we use skb->data after calling ieee80211_tx_status_irqsafe(), which
could free skb instantly.
On current kernels I do not observe practical problems related with
bug, but on 2.6.35.y it cause random system hangs when stressing
wireless link, making bisection of other problems impossible.
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
| -rw-r--r-- | drivers/net/wireless/iwlegacy/iwl-4965-tx.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/drivers/net/wireless/iwlegacy/iwl-4965-tx.c b/drivers/net/wireless/iwlegacy/iwl-4965-tx.c index 5c40502f869a..fbec88d48f1b 100644 --- a/drivers/net/wireless/iwlegacy/iwl-4965-tx.c +++ b/drivers/net/wireless/iwlegacy/iwl-4965-tx.c @@ -1127,12 +1127,16 @@ int iwl4965_tx_queue_reclaim(struct iwl_priv *priv, int txq_id, int index) q->read_ptr = iwl_legacy_queue_inc_wrap(q->read_ptr, q->n_bd)) { tx_info = &txq->txb[txq->q.read_ptr]; - iwl4965_tx_status(priv, tx_info, - txq_id >= IWL4965_FIRST_AMPDU_QUEUE); + + if (WARN_ON_ONCE(tx_info->skb == NULL)) + continue; hdr = (struct ieee80211_hdr *)tx_info->skb->data; - if (hdr && ieee80211_is_data_qos(hdr->frame_control)) + if (ieee80211_is_data_qos(hdr->frame_control)) nfreed++; + + iwl4965_tx_status(priv, tx_info, + txq_id >= IWL4965_FIRST_AMPDU_QUEUE); tx_info->skb = NULL; priv->cfg->ops->lib->txq_free_tfd(priv, txq); |