| Message ID | 20190430093212.28425-1-alexandre.belloni@bootlin.com |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [1/4] rtc: digicolor: fix possible race condition | expand |
Hi Alexandre, On Tue, Apr 30 2019, Alexandre Belloni wrote: > 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 > struct before requesting the IRQ. > > Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Acked-by: Baruch Siach <baruch@tkos.co.il> baruch > --- > drivers/rtc/rtc-digicolor.c | 12 +++++++----- > 1 file changed, 7 insertions(+), 5 deletions(-) > > diff --git a/drivers/rtc/rtc-digicolor.c b/drivers/rtc/rtc-digicolor.c > index b253bf1b3531..5bb14c56bc9a 100644 > --- a/drivers/rtc/rtc-digicolor.c > +++ b/drivers/rtc/rtc-digicolor.c > @@ -192,6 +192,10 @@ static int __init dc_rtc_probe(struct platform_device *pdev) > if (IS_ERR(rtc->regs)) > return PTR_ERR(rtc->regs); > > + rtc->rtc_dev = devm_rtc_allocate_device(&pdev->dev); > + if (IS_ERR(rtc->rtc_dev)) > + return PTR_ERR(rtc->rtc_dev); > + > irq = platform_get_irq(pdev, 0); > if (irq < 0) > return irq; > @@ -200,12 +204,10 @@ static int __init dc_rtc_probe(struct platform_device *pdev) > return ret; > > platform_set_drvdata(pdev, rtc); > - rtc->rtc_dev = devm_rtc_device_register(&pdev->dev, pdev->name, > - &dc_rtc_ops, THIS_MODULE); > - if (IS_ERR(rtc->rtc_dev)) > - return PTR_ERR(rtc->rtc_dev); > > - return 0; > + rtc->rtc_dev->ops = &dc_rtc_ops; > + > + return rtc_register_device(rtc->rtc_dev); > } > > static const struct of_device_id dc_dt_ids[] = {
diff --git a/drivers/rtc/rtc-digicolor.c b/drivers/rtc/rtc-digicolor.c index b253bf1b3531..5bb14c56bc9a 100644 --- a/drivers/rtc/rtc-digicolor.c +++ b/drivers/rtc/rtc-digicolor.c @@ -192,6 +192,10 @@ static int __init dc_rtc_probe(struct platform_device *pdev) if (IS_ERR(rtc->regs)) return PTR_ERR(rtc->regs); + rtc->rtc_dev = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(rtc->rtc_dev)) + return PTR_ERR(rtc->rtc_dev); + irq = platform_get_irq(pdev, 0); if (irq < 0) return irq; @@ -200,12 +204,10 @@ static int __init dc_rtc_probe(struct platform_device *pdev) return ret; platform_set_drvdata(pdev, rtc); - rtc->rtc_dev = devm_rtc_device_register(&pdev->dev, pdev->name, - &dc_rtc_ops, THIS_MODULE); - if (IS_ERR(rtc->rtc_dev)) - return PTR_ERR(rtc->rtc_dev); - return 0; + rtc->rtc_dev->ops = &dc_rtc_ops; + + return rtc_register_device(rtc->rtc_dev); } static const struct of_device_id dc_dt_ids[] = {
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 struct before requesting the IRQ. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> --- drivers/rtc/rtc-digicolor.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-)