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=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 04DF8C76195 for ; Fri, 19 Jul 2019 03:10:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DC26620873 for ; Fri, 19 Jul 2019 03:10:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726484AbfGSDKW (ORCPT ); Thu, 18 Jul 2019 23:10:22 -0400 Received: from inva021.nxp.com ([92.121.34.21]:57136 "EHLO inva021.nxp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726055AbfGSDKV (ORCPT ); Thu, 18 Jul 2019 23:10:21 -0400 Received: from inva021.nxp.com (localhost [127.0.0.1]) by inva021.eu-rdc02.nxp.com (Postfix) with ESMTP id 4C2EA200205; Fri, 19 Jul 2019 05:10:19 +0200 (CEST) Received: from invc005.ap-rdc01.nxp.com (invc005.ap-rdc01.nxp.com [165.114.16.14]) by inva021.eu-rdc02.nxp.com (Postfix) with ESMTP id 4A4AA200072; Fri, 19 Jul 2019 05:10:16 +0200 (CEST) Received: from titan.ap.freescale.net (TITAN.ap.freescale.net [10.192.208.233]) by invc005.ap-rdc01.nxp.com (Postfix) with ESMTP id 3BB04402A9; Fri, 19 Jul 2019 11:10:12 +0800 (SGT) From: Anson.Huang@nxp.com To: a.zummo@towertech.it, alexandre.belloni@bootlin.com, linux-rtc@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Linux-imx@nxp.com Subject: [PATCH V2] rtc: snvs: fix possible race condition Date: Fri, 19 Jul 2019 11:01:02 +0800 Message-Id: <20190719030102.6141-1-Anson.Huang@nxp.com> X-Mailer: git-send-email 2.9.5 X-Virus-Scanned: ClamAV using ClamSMTP Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Anson Huang The RTC IRQ is requested before the struct rtc_device is allocated, this may lead to a NULL pointer dereference in IRQ handler. To fix this issue, allocating the rtc_device struct and register rtc device before requesting the RTC IRQ. Using devm_rtc_allocate_device/rtc_register_device instead of devm_rtc_device_register. Signed-off-by: Anson Huang --- Changes since V1: - move devm_request_irq() to after rtc device register done, make sure everything is ready before enabling IRQ. --- drivers/rtc/rtc-snvs.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/drivers/rtc/rtc-snvs.c b/drivers/rtc/rtc-snvs.c index 7ee673a2..d9650e7 100644 --- a/drivers/rtc/rtc-snvs.c +++ b/drivers/rtc/rtc-snvs.c @@ -279,6 +279,10 @@ static int snvs_rtc_probe(struct platform_device *pdev) if (!data) return -ENOMEM; + data->rtc = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(data->rtc)) + return PTR_ERR(data->rtc); + data->regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "regmap"); if (IS_ERR(data->regmap)) { @@ -335,6 +339,13 @@ static int snvs_rtc_probe(struct platform_device *pdev) if (ret) dev_err(&pdev->dev, "failed to enable irq wake\n"); + data->rtc->ops = &snvs_rtc_ops; + ret = rtc_register_device(data->rtc); + if (ret) { + dev_err(&pdev->dev, "failed to register rtc: %d\n", ret); + goto error_rtc_device_register; + } + ret = devm_request_irq(&pdev->dev, data->irq, snvs_rtc_irq_handler, IRQF_SHARED, "rtc alarm", &pdev->dev); if (ret) { @@ -343,14 +354,6 @@ static int snvs_rtc_probe(struct platform_device *pdev) goto error_rtc_device_register; } - data->rtc = devm_rtc_device_register(&pdev->dev, pdev->name, - &snvs_rtc_ops, THIS_MODULE); - if (IS_ERR(data->rtc)) { - ret = PTR_ERR(data->rtc); - dev_err(&pdev->dev, "failed to register rtc: %d\n", ret); - goto error_rtc_device_register; - } - return 0; error_rtc_device_register: -- 2.7.4