clk: hisilicon: fix potential NULL dereference in hisi_clk_alloc()

platform_get_resource() may fail and return NULL, so we should
better check it's return value to avoid a NULL pointer dereference
a bit later in the code.

This is detected by Coccinelle semantic patch.

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

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

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Fixes: 322269163a36 ("clk: hisilicon: add hisi_clk_alloc function.")
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

diff --git a/drivers/clk/hisilicon/clk.c b/drivers/clk/hisilicon/clk.c
index 29046b8334c2ffdb37bfe6dc76ee94a64e956d29..953c8dacef8b095b89e94db1553ac18e54b559ac 100644 (file)
--- a/drivers/clk/hisilicon/clk.c
+++ b/drivers/clk/hisilicon/clk.c
@@ -49,6 +49,8 @@ struct hisi_clock_data *hisi_clk_alloc(struct platform_device *pdev,
                return NULL;
 
        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       if (!res)
+               return NULL;
        clk_data->base = devm_ioremap(&pdev->dev,
                                res->start, resource_size(res));
        if (!clk_data->base)