From: Alexandre Belloni <alexandre.belloni@bootlin.com>
To: Alessandro Zummo <a.zummo@towertech.it>,
Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: linux-rtc@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 1/6] rtc: 88pm860x: fix possible race condition
Date: Wed, 11 Mar 2020 23:39:51 +0100 [thread overview]
Message-ID: <20200311223956.51352-1-alexandre.belloni@bootlin.com> (raw)
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
next reply other threads:[~2020-03-11 22:40 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-11 22:39 Alexandre Belloni [this message]
2020-03-11 22:39 ` [PATCH 2/6] rtc: 88pm860x: stop setting a default time Alexandre Belloni
2020-03-11 22:39 ` [PATCH 3/6] rtc: 88pm860x: stop calling unused callback Alexandre Belloni
2020-03-11 22:39 ` [PATCH 4/6] rtc: 88pm860x: set range Alexandre Belloni
2020-03-11 22:39 ` [PATCH 5/6] rtc: 88pm860x: stop mangling alarm time Alexandre Belloni
2020-03-11 22:39 ` [PATCH 6/6] rtc: 88pm860x: switch to rtc_time64_to_tm/rtc_tm_to_time64 Alexandre Belloni
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