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rtc: ds1374: 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.

Link: https://lore.kernel.org/r/20200306073404.56921-1-alexandre.belloni@bootlin.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
This commit is contained in:
Alexandre Belloni 2020-03-06 08:34:01 +01:00
parent d238df15e5
commit c11af8131a
1 changed files with 9 additions and 6 deletions
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15
drivers/rtc/rtc-ds1374.c
View File

@ -620,6 +620,10 @@ static int ds1374_probe(struct i2c_client *client,
if (!ds1374)
return -ENOMEM;
ds1374->rtc = devm_rtc_allocate_device(&client->dev);
if (IS_ERR(ds1374->rtc))
return PTR_ERR(ds1374->rtc);
ds1374->client = client;
i2c_set_clientdata(client, ds1374);
@ -641,12 +645,11 @@ static int ds1374_probe(struct i2c_client *client,
device_set_wakeup_capable(&client->dev, 1);
}
ds1374->rtc = devm_rtc_device_register(&client->dev, client->name,
&ds1374_rtc_ops, THIS_MODULE);
if (IS_ERR(ds1374->rtc)) {
dev_err(&client->dev, "unable to register the class device\n");
return PTR_ERR(ds1374->rtc);
}
ds1374->rtc->ops = &ds1374_rtc_ops;
ret = rtc_register_device(ds1374->rtc);
if (ret)
return ret;
#ifdef CONFIG_RTC_DRV_DS1374_WDT
save_client = client;