[PATCH net v5] net: mvpp2: fix possible invalid pointer dereference

[Hui Tang]

It will cause invalid pointer dereference to priv->cm3_base behind,
if PTR_ERR(priv->cm3_base) in mvpp2_get_sram().

Fixes: a59d354208a7 ("net: mvpp2: enable global flow control")
Signed-off-by: Hui Tang <tanghui20@xxxxxxxxxx>
---
v1 -> v2: patch title include target
v2 -> v3: keep priv->cm3_base NULL if devm_ioremap_resource() failed
v3 -> v4: change if (priv->cm3_base) to if (base)
v4 -> v5: use the idiomatic error handling, keep success path un-indented
---
 drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
index d98f7e9a480e..4f3c1757620c 100644
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
@@ -7349,6 +7349,7 @@ static int mvpp2_get_sram(struct platform_device *pdev,
 			  struct mvpp2 *priv)
 {
 	struct resource *res;
+	void __iomem *base;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
 	if (!res) {
@@ -7359,9 +7360,12 @@ static int mvpp2_get_sram(struct platform_device *pdev,
 		return 0;
 	}
 
-	priv->cm3_base = devm_ioremap_resource(&pdev->dev, res);
+	base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
 
-	return PTR_ERR_OR_ZERO(priv->cm3_base);
+	priv->cm3_base = base;
+	return 0;
 }
 
 static int mvpp2_probe(struct platform_device *pdev)
-- 
2.17.1