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    Subject[PATCH 1/6] rtc: 88pm860x: fix possible race condition
    Date
    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.

    Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
    ---
    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
    --
    2.24.1
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