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

[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@seu.edu.cn>
---
 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

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

[netdev-bot+sinfo]

Hi!

This is an automated message. This series looks like a fix, but its
commit messages seem to be missing some information:

 - How the issue was discovered, e.g. hit in production, hit during
   development, syzbot report, manual code inspection, LLM or static
   analysis tool scan.

 - Whether the issue was actually triggered, or is only theoretical
   (e.g. found by code inspection). If it was triggered please include
   the symptoms, like the stack trace or error messages.

 - What hardware the change was tested on. For driver fixes please
   mention the device (and if relevant firmware version) used for
   testing, or say that the change was not tested on real hardware.

Please do not repost the series just to address the above. Instead,
reply to this email with the missing information, so that reviewers
can take it into account. If the series needs another revision for
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then.

The evaluation is done by an LLM so it may be wrong, if you think
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