From 2624e96ce16bacae0e422d5775eac6d4fc33239a Mon Sep 17 00:00:00 2001 From: Stanislaw Gruszka Date: Wed, 20 Apr 2011 16:02:58 +0200 Subject: [PATCH] iwlwifi: fix possible data overwrite in hcmd callback My commit 3598e1774c94e55c71b585340e7dc4538f310e3f "iwlwifi: fix enqueue hcmd race conditions" move hcmd callback after command queue reclaim, to avoid call it with hcmd_lock. But since queue read index was updated, cmd data can be overwritten. Fix problem by calling callback before taking hcmd_lock and queue reclaim. Signed-off-by: Stanislaw Gruszka Acked-by: Wey-Yi Guy Signed-off-by: John W. Linville --- drivers/net/wireless/iwlwifi/iwl-tx.c | 15 ++++----------- 1 file changed, 4 insertions(+), 11 deletions(-) diff --git a/drivers/net/wireless/iwlwifi/iwl-tx.c b/drivers/net/wireless/iwlwifi/iwl-tx.c index 80c3565a66ae..52b1b66f32d0 100644 --- a/drivers/net/wireless/iwlwifi/iwl-tx.c +++ b/drivers/net/wireless/iwlwifi/iwl-tx.c @@ -621,9 +621,6 @@ void iwl_tx_cmd_complete(struct iwl_priv *priv, struct iwl_rx_mem_buffer *rxb) struct iwl_cmd_meta *meta; struct iwl_tx_queue *txq = &priv->txq[priv->cmd_queue]; unsigned long flags; - void (*callback) (struct iwl_priv *priv, struct iwl_device_cmd *cmd, - struct iwl_rx_packet *pkt); - /* If a Tx command is being handled and it isn't in the actual * command queue then there a command routing bug has been introduced @@ -637,8 +634,6 @@ void iwl_tx_cmd_complete(struct iwl_priv *priv, struct iwl_rx_mem_buffer *rxb) return; } - spin_lock_irqsave(&priv->hcmd_lock, flags); - cmd_index = get_cmd_index(&txq->q, index, huge); cmd = txq->cmd[cmd_index]; meta = &txq->meta[cmd_index]; @@ -648,13 +643,14 @@ void iwl_tx_cmd_complete(struct iwl_priv *priv, struct iwl_rx_mem_buffer *rxb) dma_unmap_len(meta, len), PCI_DMA_BIDIRECTIONAL); - callback = NULL; /* Input error checking is done when commands are added to queue. */ if (meta->flags & CMD_WANT_SKB) { meta->source->reply_page = (unsigned long)rxb_addr(rxb); rxb->page = NULL; - } else - callback = meta->callback; + } else if (meta->callback) + meta->callback(priv, cmd, pkt); + + spin_lock_irqsave(&priv->hcmd_lock, flags); iwl_hcmd_queue_reclaim(priv, txq_id, index, cmd_index); @@ -669,7 +665,4 @@ void iwl_tx_cmd_complete(struct iwl_priv *priv, struct iwl_rx_mem_buffer *rxb) meta->flags = 0; spin_unlock_irqrestore(&priv->hcmd_lock, flags); - - if (callback) - callback(priv, cmd, pkt); } -- 2.20.1