Commit 189b3299 authored Feb 07, 2014 by Aaron Durbin Committed by John W. Linville Feb 12, 2014

mwifiex: don't leak DMA command skbuffs



The current mwifiex pcie driver assumed that it would get
its cmdrsp_complete() callback called before another command
was sent to unmap the command's skbuff. However, that is not
true. The mwifiex_check_ps_cond() will send a sleep command
to the card without having adapter->curr_cmd set. Within the
workqueue's state machine the adapter's state would be set
to allow commands (curr_cmd = NULL && cmd_sent = false) after
having receieved the response from the sleep command. The
card->cmd_buf would then be overridden with the new command
but the first command's skbuff was not unmapped. This leaks
mapped skbuffs when a bounce buffer is employed.

To rectify this unmap the card->cmd_buf when the response is
received from the card instead of waiting for the
cmdrsp_complete() callback.

Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Paul Stewart <pstew@chromium.org>
Reviewed-by: Avinash Patil <patila@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

parent dbccc92b

drivers/net/wireless/mwifiex/pcie.c

+7 −7

Original line number	Diff line number	Diff line
		@@ -1513,6 +1513,13 @@ static int mwifiex_pcie_process_cmd_complete(struct mwifiex_adapter *adapter)

		mwifiex_unmap_pci_memory(adapter, skb, PCI_DMA_FROMDEVICE);

		/* Unmap the command as a response has been received. */
		if (card->cmd_buf) {
		mwifiex_unmap_pci_memory(adapter, card->cmd_buf,
		PCI_DMA_TODEVICE);
		card->cmd_buf = NULL;
		}

		pkt_len = ((__le16 )skb->data);
		rx_len = le16_to_cpu(pkt_len);
		skb_trim(skb, rx_len);
		@@ -1569,7 +1576,6 @@ static int mwifiex_pcie_cmdrsp_complete(struct mwifiex_adapter *adapter,
		struct sk_buff *skb)
		{
		struct pcie_service_card *card = adapter->card;
		struct sk_buff *skb_tmp;

		if (skb) {
		card->cmdrsp_buf = skb;
		@@ -1579,12 +1585,6 @@ static int mwifiex_pcie_cmdrsp_complete(struct mwifiex_adapter *adapter,
		return -1;
		}

		skb_tmp = card->cmd_buf;
		if (skb_tmp) {
		mwifiex_unmap_pci_memory(adapter, skb_tmp, PCI_DMA_FROMDEVICE);
		card->cmd_buf = NULL;
		}

		return 0;
		}