[ 103/123] solos-pci: fix double-free of TX skb in DMA mode

From: Greg Kroah-Hartman
Date: Wed Jan 09 2013 - 15:53:30 EST


3.7-stable review patch. If anyone has any objections, please let me know.

------------------

From: David Woodhouse <dwmw2@xxxxxxxxxxxxx>

commit cae49ede00ec3d0cda290b03fee55b72b49efc11 upstream.

We weren't clearing card->tx_skb[port] when processing the TX done interrupt.
If there wasn't another skb ready to transmit immediately, this led to a
double-free because we'd free it *again* next time we did have a packet to
send.

Signed-off-by: David Woodhouse <David.Woodhouse@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/atm/solos-pci.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

--- a/drivers/atm/solos-pci.c
+++ b/drivers/atm/solos-pci.c
@@ -967,10 +967,11 @@ static uint32_t fpga_tx(struct solos_car
for (port = 0; tx_pending; tx_pending >>= 1, port++) {
if (tx_pending & 1) {
struct sk_buff *oldskb = card->tx_skb[port];
- if (oldskb)
+ if (oldskb) {
pci_unmap_single(card->dev, SKB_CB(oldskb)->dma_addr,
oldskb->len, PCI_DMA_TODEVICE);
-
+ card->tx_skb[port] = NULL;
+ }
spin_lock(&card->tx_queue_lock);
skb = skb_dequeue(&card->tx_queue[port]);
if (!skb)


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