From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.bootlin.com ([62.4.15.54]:47051 "EHLO mail.bootlin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726632AbeIJB3v (ORCPT ); Sun, 9 Sep 2018 21:29:51 -0400 From: Alexandre Belloni To: linux-rtc@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mediatek@lists.infradead.org, Alexandre Belloni , Eddie Huang , Sean Wang Subject: [PATCH 1/3] rtc: mt6397: fix possible race condition Date: Sun, 9 Sep 2018 22:38:46 +0200 Message-Id: <20180909203848.3470-1-alexandre.belloni@bootlin.com> MIME-Version: 1.0 Sender: linux-rtc-owner@vger.kernel.org List-ID: 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. Cc: Eddie Huang Cc: Sean Wang Signed-off-by: Alexandre Belloni --- 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 385f8303bb41..e9a25ec4d434 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); -- 2.19.0.rc2