[PATCH 4/7] net: hisi_femac: manage the netdev lifetime with devres

[Jiale Yao]

hisi_femac_drv_remove() frees the netdev while the shared managed IRQ
remains registered until devres cleanup. Its handler uses the netdev as
private data, so an interrupt in this window can dereference freed
memory.

Manage the netdev allocation with devres so the later IRQ resource is
released before the netdev.

Fixes: 542ae60af24f ("net: hisilicon: Add Fast Ethernet MAC driver")

Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Jiale Yao <yaojiale02@xxxxxxx>
---
 drivers/net/ethernet/hisilicon/hisi_femac.c | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/hisilicon/hisi_femac.c b/drivers/net/ethernet/hisilicon/hisi_femac.c
index d244a40df430..d369824fa4e8 100644
--- a/drivers/net/ethernet/hisilicon/hisi_femac.c
+++ b/drivers/net/ethernet/hisilicon/hisi_femac.c
@@ -774,7 +774,7 @@ static int hisi_femac_drv_probe(struct platform_device *pdev)
 	struct phy_device *phy;
 	int ret;
 
-	ndev = alloc_etherdev(sizeof(*priv));
+	ndev = devm_alloc_etherdev(dev, sizeof(*priv));
 	if (!ndev)
 		return -ENOMEM;
 
@@ -788,26 +788,26 @@ static int hisi_femac_drv_probe(struct platform_device *pdev)
 	priv->port_base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(priv->port_base)) {
 		ret = PTR_ERR(priv->port_base);
-		goto out_free_netdev;
+		goto out_return;
 	}
 
 	priv->glb_base = devm_platform_ioremap_resource(pdev, 1);
 	if (IS_ERR(priv->glb_base)) {
 		ret = PTR_ERR(priv->glb_base);
-		goto out_free_netdev;
+		goto out_return;
 	}
 
 	priv->clk = devm_clk_get(&pdev->dev, NULL);
 	if (IS_ERR(priv->clk)) {
 		dev_err(dev, "failed to get clk\n");
 		ret = -ENODEV;
-		goto out_free_netdev;
+		goto out_return;
 	}
 
 	ret = clk_prepare_enable(priv->clk);
 	if (ret) {
 		dev_err(dev, "failed to enable clk %d\n", ret);
-		goto out_free_netdev;
+		goto out_return;
 	}
 
 	priv->mac_rst = devm_reset_control_get(dev, "mac");
@@ -887,9 +887,7 @@ static int hisi_femac_drv_probe(struct platform_device *pdev)
 	phy_disconnect(phy);
 out_disable_clk:
 	clk_disable_unprepare(priv->clk);
-out_free_netdev:
-	free_netdev(ndev);
-
+out_return:
 	return ret;
 }
 
@@ -903,7 +901,6 @@ static void hisi_femac_drv_remove(struct platform_device *pdev)
 
 	phy_disconnect(ndev->phydev);
 	clk_disable_unprepare(priv->clk);
-	free_netdev(ndev);
 }
 
 #ifdef CONFIG_PM
-- 
2.34.1