[PATCH net] net: calxeda: cancel timeout work before freeing rings

[Hongyan Xu]

The transmit timeout paths queue tx_timeout_work, which accesses the DMA
rings and NAPI state. xgmac_stop() can free the rings without waiting
for a queued timeout worker, so the worker may subsequently use freed
storage.

Stop transmit and interrupt publication, cancel the timeout work, and
only then disable NAPI and release the rings.

Fixes: 85c10f282861 ("net: add calxeda xgmac ethernet driver")
Signed-off-by: Hongyan Xu <getshell@xxxxxxxxxx>
---
 drivers/net/ethernet/calxeda/xgmac.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/calxeda/xgmac.c b/drivers/net/ethernet/calxeda/xgmac.c
index a2410fba6be2..63296469bd85 100644
--- a/drivers/net/ethernet/calxeda/xgmac.c
+++ b/drivers/net/ethernet/calxeda/xgmac.c
@@ -1046,12 +1046,10 @@ static int xgmac_stop(struct net_device *dev)
 {
 	struct xgmac_priv *priv = netdev_priv(dev);
 
-	if (readl(priv->base + XGMAC_DMA_INTR_ENA))
-		napi_disable(&priv->napi);
-
-	writel(0, priv->base + XGMAC_DMA_INTR_ENA);
-
 	netif_tx_disable(dev);
+	writel(0, priv->base + XGMAC_DMA_INTR_ENA);
+	cancel_work_sync(&priv->tx_timeout_work);
+	napi_disable(&priv->napi);
 
 	/* Disable the MAC core */
 	xgmac_mac_disable(priv->base);
-- 
2.50.1.windows.1