From 7d61cbb945a753af08e247b5f10bdd5dbb8d6c80 Mon Sep 17 00:00:00 2001 From: Alexandre Belloni Date: Mon, 24 Sep 2018 16:25:34 +0200 Subject: [PATCH] rtc: armada38x: fix possible race condition 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: Alexandre Belloni --- drivers/rtc/rtc-armada38x.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/drivers/rtc/rtc-armada38x.c b/drivers/rtc/rtc-armada38x.c index bde53c8ccee2..b74338d6dde6 100644 --- a/drivers/rtc/rtc-armada38x.c +++ b/drivers/rtc/rtc-armada38x.c @@ -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"); @@ -560,28 +564,24 @@ 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; + + return ret; } #ifdef CONFIG_PM_SLEEP -- 2.45.2