From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752237AbeEQUTT (ORCPT ); Thu, 17 May 2018 16:19:19 -0400 Received: from mail.bootlin.com ([62.4.15.54]:38534 "EHLO mail.bootlin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751409AbeEQUTQ (ORCPT ); Thu, 17 May 2018 16:19:16 -0400 From: Alexandre Belloni To: linux-rtc@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Alexandre Belloni Subject: [PATCH 3/5] rtc: 88pm80x: fix possible race condition Date: Thu, 17 May 2018 22:18:58 +0200 Message-Id: <20180517201900.22055-3-alexandre.belloni@bootlin.com> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180517201900.22055-1-alexandre.belloni@bootlin.com> References: <20180517201900.22055-1-alexandre.belloni@bootlin.com> Sender: linux-kernel-owner@vger.kernel.org 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. Signed-off-by: Alexandre Belloni --- drivers/rtc/rtc-88pm80x.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/drivers/rtc/rtc-88pm80x.c b/drivers/rtc/rtc-88pm80x.c index f60c0d73c2f3..dae527f8c58e 100644 --- a/drivers/rtc/rtc-88pm80x.c +++ b/drivers/rtc/rtc-88pm80x.c @@ -290,6 +290,10 @@ static int pm80x_rtc_probe(struct platform_device *pdev) info->dev = &pdev->dev; dev_set_drvdata(&pdev->dev, info); + info->rtc_dev = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(info->rtc_dev)) + return PTR_ERR(info->rtc_dev); + ret = pm80x_request_irq(chip, info->irq, rtc_update_handler, IRQF_ONESHOT, "rtc", info); if (ret < 0) { @@ -298,10 +302,10 @@ static int pm80x_rtc_probe(struct platform_device *pdev) goto out; } - info->rtc_dev = devm_rtc_device_register(&pdev->dev, "88pm80x-rtc", - &pm80x_rtc_ops, THIS_MODULE); - if (IS_ERR(info->rtc_dev)) { - ret = PTR_ERR(info->rtc_dev); + info->rtc_dev->ops = &pm80x_rtc_ops; + + ret = rtc_register_device(info->rtc_dev); + if (ret) { dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret); goto out_rtc; } -- 2.17.0