reset: hisilicon: fix potential NULL pointer dereference

There is a potential execution path in which function
platform_get_resource() returns NULL. If this happens,
we will end up having a NULL pointer dereference.

Fix this by replacing devm_ioremap with devm_ioremap_resource,
which has the NULL check and the memory region request.

This code was detected with the help of Coccinelle.

Cc: stable@vger.kernel.org
Fixes: 97b7129cd2af ("reset: hisilicon: change the definition of hisi_reset_init")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

diff --git a/drivers/clk/hisilicon/reset.c b/drivers/clk/hisilicon/reset.c
index 2a5015c..43e82fa 100644 (file)
--- a/drivers/clk/hisilicon/reset.c
+++ b/drivers/clk/hisilicon/reset.c
@@ -109,9 +109,8 @@ struct hisi_reset_controller *hisi_reset_init(struct platform_device *pdev)
                return NULL;
 
        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-       rstc->membase = devm_ioremap(&pdev->dev,
-                               res->start, resource_size(res));
-       if (!rstc->membase)
+       rstc->membase = devm_ioremap_resource(&pdev->dev, res);
+       if (IS_ERR(rstc->membase))
                return NULL;
 
        spin_lock_init(&rstc->lock);