[PATCH] remoteproc: qcom: Fix potential NULL dereference in adsp_init_mmio()

From: Zhang Changzhong <zhangchangzhong@huawei.com>
To: Andy Gross <agross@kernel.org>,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	Ohad Ben-Cohen <ohad@wizery.com>,
	Sibi Sankar <sibis@codeaurora.org>,
	Rohit kumar <rohitkr@codeaurora.org>
Cc: Zhang Changzhong <zhangchangzhong@huawei.com>,
	<linux-arm-msm@vger.kernel.org>,
	<linux-remoteproc@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>
Subject: [PATCH] remoteproc: qcom: Fix potential NULL dereference in adsp_init_mmio()
Date: Tue, 8 Dec 2020 09:54:20 +0800	[thread overview]
Message-ID: <1607392460-20516-1-git-send-email-zhangchangzhong@huawei.com> (raw)

platform_get_resource() may fail and in this case a NULL dereference
will occur.

Fix it to use devm_platform_ioremap_resource() instead of calling
platform_get_resource() and devm_ioremap().

This is detected by Coccinelle semantic patch.

@@
expression pdev, res, n, t, e, e1, e2;
@@

res = \(platform_get_resource\|platform_get_resource_byname\)(pdev, t,
n);
+ if (!res)
+   return -EINVAL;
... when != res == NULL
e = devm_ioremap(e1, res->start, e2);

Fixes: dc160e449122 ("remoteproc: qcom: Introduce Non-PAS ADSP PIL driver")
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
---
 drivers/remoteproc/qcom_q6v5_adsp.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/remoteproc/qcom_q6v5_adsp.c b/drivers/remoteproc/qcom_q6v5_adsp.c
index efb2c1a..8674b73 100644
--- a/drivers/remoteproc/qcom_q6v5_adsp.c
+++ b/drivers/remoteproc/qcom_q6v5_adsp.c
@@ -362,15 +362,12 @@ static int adsp_init_mmio(struct qcom_adsp *adsp,
 				struct platform_device *pdev)
 {
 	struct device_node *syscon;
-	struct resource *res;
 	int ret;
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	adsp->qdsp6ss_base = devm_ioremap(&pdev->dev, res->start,
-			resource_size(res));
-	if (!adsp->qdsp6ss_base) {
+	adsp->qdsp6ss_base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(adsp->qdsp6ss_base)) {
 		dev_err(adsp->dev, "failed to map QDSP6SS registers\n");
-		return -ENOMEM;
+		return PTR_ERR(adsp->qdsp6ss_base);
 	}
 
 	syscon = of_parse_phandle(pdev->dev.of_node, "qcom,halt-regs", 0);
-- 
2.9.5

