rtc: snvs: fix possible race condition (6fd4fe9b) · Commits · 戴 / test

The RTC IRQ is requested before the struct rtc_device is allocated, this may lead to a NULL pointer dereference in IRQ handler. To fix this issue, allocating the rtc_device struct before requesting the RTC IRQ using devm_rtc_allocate_device, and use rtc_register_device to register the RTC device. Signed-off-by:

Anson Huang <Anson.Huang@nxp.com> Reviewed-by:

Dong Aisheng <aisheng.dong@nxp.com> Link: https://lore.kernel.org/r/20190716071858.36750-1-Anson.Huang@nxp.com Signed-off-by:

Alexandre Belloni <alexandre.belloni@bootlin.com>

drivers/rtc/rtc-snvs.c

+7 −4

Original line number	Diff line number	Diff line
		@@ -279,6 +279,10 @@ static int snvs_rtc_probe(struct platform_device *pdev)
		if (!data)
		return -ENOMEM;

		data->rtc = devm_rtc_allocate_device(&pdev->dev);
		if (IS_ERR(data->rtc))
		return PTR_ERR(data->rtc);

		data->regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "regmap");

		if (IS_ERR(data->regmap)) {
		@@ -343,10 +347,9 @@ static int snvs_rtc_probe(struct platform_device *pdev)
		goto error_rtc_device_register;
		}

		data->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
		&snvs_rtc_ops, THIS_MODULE);
		if (IS_ERR(data->rtc)) {
		ret = PTR_ERR(data->rtc);
		data->rtc->ops = &snvs_rtc_ops;
		ret = rtc_register_device(data->rtc);
		if (ret) {
		dev_err(&pdev->dev, "failed to register rtc: %d\n", ret);
		goto error_rtc_device_register;
		}

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