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Commit bd2ab045 authored by Alexandre Belloni's avatar Alexandre Belloni Committed by Greg Kroah-Hartman
Browse files

rtc: xgene: fix possible race condition 



[ Upstream commit a652e00ee1233e251a337c28e18a1da59224e5ce ]

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: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent e29aba14

drivers/rtc/rtc-xgene.c

+11 −7
Original line number Original line Diff line number Diff line
@@ -168,6 +168,10 @@ static int xgene_rtc_probe(struct platform_device *pdev) 
	if (IS_ERR(pdata->csr_base))

	if (IS_ERR(pdata->csr_base))

		return PTR_ERR(pdata->csr_base);

		return PTR_ERR(pdata->csr_base);





	pdata->rtc = devm_rtc_allocate_device(&pdev->dev);

	if (IS_ERR(pdata->rtc))

		return PTR_ERR(pdata->rtc);



	irq = platform_get_irq(pdev, 0);

	irq = platform_get_irq(pdev, 0);

	if (irq < 0) {

	if (irq < 0) {

		dev_err(&pdev->dev, "No IRQ resource\n");

		dev_err(&pdev->dev, "No IRQ resource\n");
@@ -198,15 +202,15 @@ static int xgene_rtc_probe(struct platform_device *pdev) 
		return ret;

		return ret;

	}

	}





	pdata->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,

					 &xgene_rtc_ops, THIS_MODULE);

	if (IS_ERR(pdata->rtc)) {

		clk_disable_unprepare(pdata->clk);

		return PTR_ERR(pdata->rtc);

	}



	/* HW does not support update faster than 1 seconds */

	/* HW does not support update faster than 1 seconds */

	pdata->rtc->uie_unsupported = 1;

	pdata->rtc->uie_unsupported = 1;

	pdata->rtc->ops = &xgene_rtc_ops;



	ret = rtc_register_device(pdata->rtc);

	if (ret) {

		clk_disable_unprepare(pdata->clk);

		return ret;

	}





	return 0;

	return 0;

}

}