| From 0be5073dd79810a242e120feb935937c51c0bc5b Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Sun, 9 Sep 2018 22:38:46 +0200 |
| Subject: rtc: mt6397: fix possible race condition |
| |
| From: Alexandre Belloni <alexandre.belloni@bootlin.com> |
| |
| [ Upstream commit babab2f86440352d24e76118fdd7d40cab5fd7bf ] |
| |
| 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 |
| before requesting the IRQ. |
| |
| Acked-by: Eddie Huang <eddie.huang@mediatek.com> |
| Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| drivers/rtc/rtc-mt6397.c | 13 ++++++++----- |
| 1 file changed, 8 insertions(+), 5 deletions(-) |
| |
| diff --git a/drivers/rtc/rtc-mt6397.c b/drivers/rtc/rtc-mt6397.c |
| index 385f8303bb412..e9a25ec4d434f 100644 |
| --- a/drivers/rtc/rtc-mt6397.c |
| +++ b/drivers/rtc/rtc-mt6397.c |
| @@ -332,6 +332,10 @@ static int mtk_rtc_probe(struct platform_device *pdev) |
| |
| platform_set_drvdata(pdev, rtc); |
| |
| + rtc->rtc_dev = devm_rtc_allocate_device(rtc->dev); |
| + if (IS_ERR(rtc->rtc_dev)) |
| + return PTR_ERR(rtc->rtc_dev); |
| + |
| ret = request_threaded_irq(rtc->irq, NULL, |
| mtk_rtc_irq_handler_thread, |
| IRQF_ONESHOT | IRQF_TRIGGER_HIGH, |
| @@ -344,11 +348,11 @@ static int mtk_rtc_probe(struct platform_device *pdev) |
| |
| device_init_wakeup(&pdev->dev, 1); |
| |
| - rtc->rtc_dev = rtc_device_register("mt6397-rtc", &pdev->dev, |
| - &mtk_rtc_ops, THIS_MODULE); |
| - if (IS_ERR(rtc->rtc_dev)) { |
| + rtc->rtc_dev->ops = &mtk_rtc_ops; |
| + |
| + ret = rtc_register_device(rtc->rtc_dev); |
| + if (ret) { |
| dev_err(&pdev->dev, "register rtc device failed\n"); |
| - ret = PTR_ERR(rtc->rtc_dev); |
| goto out_free_irq; |
| } |
| |
| @@ -365,7 +369,6 @@ static int mtk_rtc_remove(struct platform_device *pdev) |
| { |
| struct mt6397_rtc *rtc = platform_get_drvdata(pdev); |
| |
| - rtc_device_unregister(rtc->rtc_dev); |
| free_irq(rtc->irq, rtc->rtc_dev); |
| irq_dispose_mapping(rtc->irq); |
| |
| -- |
| 2.20.1 |
| |