From 9cf4789e6e4673d0b2c96fa6bb0c35e81b43111a Mon Sep 17 00:00:00 2001 From: Alexandre Belloni Date: Wed, 11 Mar 2020 23:39:51 +0100 Subject: [PATCH] rtc: 88pm860x: fix possible race condition The RTC IRQ is requested before the struct rtc_device is allocated, this may lead to a NULL pointer dereference in the 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. Also remove the unnecessary error message as the core already prints the info. Link: https://lore.kernel.org/r/20200311223956.51352-1-alexandre.belloni@bootlin.com Signed-off-by: Alexandre Belloni --- drivers/rtc/rtc-88pm860x.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/drivers/rtc/rtc-88pm860x.c b/drivers/rtc/rtc-88pm860x.c index 4743b16a8d84..1526402e126b 100644 --- a/drivers/rtc/rtc-88pm860x.c +++ b/drivers/rtc/rtc-88pm860x.c @@ -336,6 +336,10 @@ static int pm860x_rtc_probe(struct platform_device *pdev) info->dev = &pdev->dev; dev_set_drvdata(&pdev->dev, info); + info->rtc_dev = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(info->rtc_dev)) + return PTR_ERR(info->rtc_dev); + ret = devm_request_threaded_irq(&pdev->dev, info->irq, NULL, rtc_update_handler, IRQF_ONESHOT, "rtc", info); @@ -377,13 +381,11 @@ static int pm860x_rtc_probe(struct platform_device *pdev) } } - info->rtc_dev = devm_rtc_device_register(&pdev->dev, "88pm860x-rtc", - &pm860x_rtc_ops, THIS_MODULE); - ret = PTR_ERR(info->rtc_dev); - if (IS_ERR(info->rtc_dev)) { - dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret); + info->rtc_dev->ops = &pm860x_rtc_ops; + + ret = rtc_register_device(info->rtc_dev); + if (ret) return ret; - } /* * enable internal XO instead of internal 3.25MHz clock since it can