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From:   Colin King <colin.king@canonical.com>
To:     Ryder Lee <ryder.lee@mediatek.com>,
        Jianjun Wang <jianjun.wang@mediatek.com>,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
        Rob Herring <robh@kernel.org>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        linux-pci@vger.kernel.org, linux-mediatek@lists.infradead.org,
        linux-arm-kernel@lists.infradead.org
Cc:     kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH][next] PCI: mediatek-gen3: Add missing null pointer check
Date:   Thu, 29 Apr 2021 12:00:40 +0100
Message-Id: <20210429110040.63119-1-colin.king@canonical.com>
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From: Colin Ian King <colin.king@canonical.com>

The call to platform_get_resource_byname can potentially return null, so
add a null pointer check to avoid a null pointer dereference issue.

Addresses-Coverity: ("Dereference null return")
Fixes: 441903d9e8f0 ("PCI: mediatek-gen3: Add MediaTek Gen3 driver for MT8192")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/pci/controller/pcie-mediatek-gen3.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/pci/controller/pcie-mediatek-gen3.c b/drivers/pci/controller/pcie-mediatek-gen3.c
index 20165e4a75b2..3c5b97716d40 100644
--- a/drivers/pci/controller/pcie-mediatek-gen3.c
+++ b/drivers/pci/controller/pcie-mediatek-gen3.c
@@ -721,6 +721,8 @@ static int mtk_pcie_parse_port(struct mtk_pcie_port *port)
 	int ret;
 
 	regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "pcie-mac");
+	if (!regs)
+		return -EINVAL;
 	port->base = devm_ioremap_resource(dev, regs);
 	if (IS_ERR(port->base)) {
 		dev_err(dev, "failed to map register base\n");
-- 
2.30.2