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Commit ba8c4cc7 authored by Alexandre Belloni's avatar Alexandre Belloni Committed by Greg Kroah-Hartman
Browse files

rtc: armada38x: fix possible race condition 



[ Upstream commit 7d61cbb945a753af08e247b5f10bdd5dbb8d6c80 ]

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
before requesting the IRQ.

Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 44bb1b12

drivers/rtc/rtc-armada38x.c

+11 −11
Original line number Diff line number Diff line
@@ -514,7 +514,6 @@ MODULE_DEVICE_TABLE(of, armada38x_rtc_of_match_table); 


static __init int armada38x_rtc_probe(struct platform_device *pdev)

{

	const struct rtc_class_ops *ops;

	struct resource *res;

	struct armada38x_rtc *rtc;

	const struct of_device_id *match;
@@ -551,6 +550,11 @@ static __init int armada38x_rtc_probe(struct platform_device *pdev) 
		dev_err(&pdev->dev, "no irq\n");

		return rtc->irq;

	}



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

	if (IS_ERR(rtc->rtc_dev))

		return PTR_ERR(rtc->rtc_dev);



	if (devm_request_irq(&pdev->dev, rtc->irq, armada38x_rtc_alarm_irq,

				0, pdev->name, rtc) < 0) {

		dev_warn(&pdev->dev, "Interrupt not available.\n");
@@ -560,29 +564,25 @@ static __init int armada38x_rtc_probe(struct platform_device *pdev) 


	if (rtc->irq != -1) {

		device_init_wakeup(&pdev->dev, 1);

		ops = &armada38x_rtc_ops;

		rtc->rtc_dev->ops = &armada38x_rtc_ops;

	} else {

		/*

		 * If there is no interrupt available then we can't

		 * use the alarm

		 */

		ops = &armada38x_rtc_ops_noirq;

		rtc->rtc_dev->ops = &armada38x_rtc_ops_noirq;

	}

	rtc->data = (struct armada38x_rtc_data *)match->data;





	/* Update RTC-MBUS bridge timing parameters */

	rtc->data->update_mbus_timing(rtc);



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

						ops, THIS_MODULE);

	if (IS_ERR(rtc->rtc_dev)) {

		ret = PTR_ERR(rtc->rtc_dev);

	ret = rtc_register_device(rtc->rtc_dev);

	if (ret)

		dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);



	return ret;

}

	return 0;

}



#ifdef CONFIG_PM_SLEEP

static int armada38x_rtc_suspend(struct device *dev)