diff options
| author | Stanislaw Gruszka <sgruszka@redhat.com> | 2011-04-20 17:57:14 +0400 |
|---|---|---|
| committer | John W. Linville <linville@tuxdriver.com> | 2011-04-21 00:05:59 +0400 |
| commit | b25026981aecde3685dd0e45ad980fff9f528daa (patch) | |
| tree | db9972ab6095d6bd57978d734810e26c733338ee | |
| parent | 243e6df4ed919880d079d717641ad699c6530a03 (diff) | |
| download | linux-b25026981aecde3685dd0e45ad980fff9f528daa.tar.xz | |
iwlwifi: 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.
Cc: stable@kernel.org # 2.6.32+
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Acked-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
| -rw-r--r-- | drivers/net/wireless/iwlwifi/iwl-agn-tx.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-tx.c b/drivers/net/wireless/iwlwifi/iwl-agn-tx.c index a709d05c5868..2dd7d54a796f 100644 --- a/drivers/net/wireless/iwlwifi/iwl-agn-tx.c +++ b/drivers/net/wireless/iwlwifi/iwl-agn-tx.c @@ -1224,12 +1224,16 @@ int iwlagn_tx_queue_reclaim(struct iwl_priv *priv, int txq_id, int index) q->read_ptr = iwl_queue_inc_wrap(q->read_ptr, q->n_bd)) { tx_info = &txq->txb[txq->q.read_ptr]; - iwlagn_tx_status(priv, tx_info, - txq_id >= IWLAGN_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++; + + iwlagn_tx_status(priv, tx_info, + txq_id >= IWLAGN_FIRST_AMPDU_QUEUE); tx_info->skb = NULL; if (priv->cfg->ops->lib->txq_inval_byte_cnt_tbl) |