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From:   Hui Tang <tanghui20@huawei.com>
To:     <davem@davemloft.net>, <edumazet@google.com>, <kuba@kernel.org>,
        <mw@semihalf.com>, <linux@armlinux.org.uk>, <leon@kernel.org>,
        <andrew@lunn.ch>
CC:     <netdev@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <yusongping@huawei.com>
Subject: [PATCH net v3] net: mvpp2: fix possible invalid pointer dereference
Date:   Wed, 16 Nov 2022 10:06:17 +0800
Message-ID: <20221116020617.137247-1-tanghui20@huawei.com>
In-Reply-To: <Y3O1V4FAACa9Ed9S@lunn.ch>
References: <Y3O1V4FAACa9Ed9S@lunn.ch>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

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@huawei.com>
---
v1 -> v2: patch title include target
v2 -> v3: keep priv->cm3_base NULL if devm_ioremap_resource() failed
---
 drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 7 +++++--
 1 file changed, 5 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..9c3fbb153b5b 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 +7360,11 @@ 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(priv->cm3_base))
+		priv->cm3_base = base;
 
-	return PTR_ERR_OR_ZERO(priv->cm3_base);
+	return PTR_ERR_OR_ZERO(base);
 }
 
 static int mvpp2_probe(struct platform_device *pdev)
-- 
2.17.1