[PATCH] rtc: mt6397: check return value after calling platform_get_resource()

[Yang Yingliang]

It will cause null-ptr-deref if platform_get_resource() returns NULL,
we need check the return value.

Fixes: fc2979118f3f ("rtc: mediatek: Add MT6397 RTC driver")
Signed-off-by: Yang Yingliang <yangyingliang at huawei.com>
---
 drivers/rtc/rtc-mt6397.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/rtc/rtc-mt6397.c b/drivers/rtc/rtc-mt6397.c
index 80dc479a6ff0..1d297af80f87 100644
--- a/drivers/rtc/rtc-mt6397.c
+++ b/drivers/rtc/rtc-mt6397.c
@@ -269,6 +269,8 @@ static int mtk_rtc_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -EINVAL;
 	rtc->addr_base = res->start;
 
 	rtc->data = of_device_get_match_data(&pdev->dev);
-- 
2.25.1