From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E6E54C433F5 for ; Sun, 9 Sep 2018 20:39:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8DDA22064D for ; Sun, 9 Sep 2018 20:39:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8DDA22064D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bootlin.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726795AbeIJB3w (ORCPT ); Sun, 9 Sep 2018 21:29:52 -0400 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 Received: by mail.bootlin.com (Postfix, from userid 110) id 990CB2071D; Sun, 9 Sep 2018 22:38:57 +0200 (CEST) Received: from localhost (unknown [88.191.26.124]) by mail.bootlin.com (Postfix) with ESMTPSA id 6C27D203DC; Sun, 9 Sep 2018 22:38:57 +0200 (CEST) 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> X-Mailer: git-send-email 2.19.0.rc2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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