rtc: mxc: fix possible race condition (ebc2ec4e) · Commits · 戴 / test

The IRQ is requested before the struct rtc is allocated and registered, but this struct is used in the IRQ handler. This may lead to a NULL pointer dereference. Switch to devm_rtc_allocate_device/rtc_register_device to allocate the rtc struct before requesting the IRQ. Signed-off-by:

Alexandre Belloni <alexandre.belloni@bootlin.com>

drivers/rtc/rtc-mxc.c

+9 −7

Original line number	Diff line number	Diff line
		@@ -340,6 +340,13 @@ static int mxc_rtc_probe(struct platform_device *pdev)
		if (IS_ERR(pdata->ioaddr))
		return PTR_ERR(pdata->ioaddr);

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

		pdata->rtc = rtc;
		rtc->ops = &mxc_rtc_ops;

		pdata->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
		if (IS_ERR(pdata->clk_ipg)) {
		dev_err(&pdev->dev, "unable to get ipg clock!\n");
		@@ -402,14 +409,9 @@ static int mxc_rtc_probe(struct platform_device *pdev)
		dev_err(&pdev->dev, "failed to enable irq wake\n");
		}

		rtc = devm_rtc_device_register(&pdev->dev, pdev->name, &mxc_rtc_ops,
		THIS_MODULE);
		if (IS_ERR(rtc)) {
		ret = PTR_ERR(rtc);
		ret = rtc_register_device(rtc);
		if (ret)
		goto exit_put_clk_ref;
		}

		pdata->rtc = rtc;

		return 0;

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