commit b25026981aecde3685dd0e45ad980fff9f528daa upstream. Since
commit a120e912eb51e347f36c71b60a1d13af74d30e83 Author: Stanislaw Gruszka <[email protected]> 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: [email protected] # 2.6.32+ Signed-off-by: Stanislaw Gruszka <[email protected]> Acked-by: Wey-Yi Guy <[email protected]> Signed-off-by: John W. Linville <[email protected]> --- drivers/net/wireless/iwlwifi/iwl-tx.c | 8 ++++++-- 1 files changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireless/iwlwifi/iwl-tx.c b/drivers/net/wireless/iwlwifi/iwl-tx.c index d21c06e..c3d7dd6 100644 --- a/drivers/net/wireless/iwlwifi/iwl-tx.c +++ b/drivers/net/wireless/iwlwifi/iwl-tx.c @@ -1088,11 +1088,15 @@ int iwl_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]; - ieee80211_tx_status_irqsafe(priv->hw, tx_info->skb[0]); + + if (WARN_ON_ONCE(tx_info->skb == NULL)) + continue; hdr = (struct ieee80211_hdr *)tx_info->skb[0]->data; - if (hdr && ieee80211_is_data_qos(hdr->frame_control)) + if (ieee80211_is_data_qos(hdr->frame_control)) nfreed++; + + ieee80211_tx_status_irqsafe(priv->hw, tx_info->skb[0]); tx_info->skb[0] = NULL; if (priv->cfg->ops->lib->txq_inval_byte_cnt_tbl) -- 1.7.1 _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
