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=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,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 A6301C46467 for ; Wed, 1 Aug 2018 18:34:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6AEFD20840 for ; Wed, 1 Aug 2018 18:34:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6AEFD20840 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org 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 S2388150AbeHAUVw (ORCPT ); Wed, 1 Aug 2018 16:21:52 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:46030 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404098AbeHATDe (ORCPT ); Wed, 1 Aug 2018 15:03:34 -0400 Received: from localhost (D57E6652.static.ziggozakelijk.nl [213.126.102.82]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id C0210106F; Wed, 1 Aug 2018 17:01:27 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexandre Belloni , Sasha Levin Subject: [PATCH 4.17 159/336] rtc: tps6586x: fix possible race condition Date: Wed, 1 Aug 2018 18:48:14 +0200 Message-Id: <20180801165035.204445291@linuxfoundation.org> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180801165028.930831994@linuxfoundation.org> References: <20180801165028.930831994@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alexandre Belloni [ Upstream commit 63d22063073b0ab46d1e06fe633fb5de8f5c58e1 ] The probe function is not allowed to fail after the RTC is registered because the following may happen: CPU0: CPU1: sys_load_module() do_init_module() do_one_initcall() cmos_do_probe() rtc_device_register() __register_chrdev() cdev->owner = struct module* open("/dev/rtc0") rtc_device_unregister() module_put() free_module() module_free(mod->module_core) /* struct module *module is now freed */ chrdev_open() spin_lock(cdev_lock) cdev_get() try_module_get() module_is_live() /* dereferences already freed struct module* */ Signed-off-by: Alexandre Belloni Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/rtc/rtc-tps6586x.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) --- a/drivers/rtc/rtc-tps6586x.c +++ b/drivers/rtc/rtc-tps6586x.c @@ -276,14 +276,15 @@ static int tps6586x_rtc_probe(struct pla device_init_wakeup(&pdev->dev, 1); platform_set_drvdata(pdev, rtc); - rtc->rtc = devm_rtc_device_register(&pdev->dev, dev_name(&pdev->dev), - &tps6586x_rtc_ops, THIS_MODULE); + rtc->rtc = devm_rtc_allocate_device(&pdev->dev); if (IS_ERR(rtc->rtc)) { ret = PTR_ERR(rtc->rtc); - dev_err(&pdev->dev, "RTC device register: ret %d\n", ret); + dev_err(&pdev->dev, "RTC allocate device: ret %d\n", ret); goto fail_rtc_register; } + rtc->rtc->ops = &tps6586x_rtc_ops; + ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL, tps6586x_rtc_irq, IRQF_ONESHOT, @@ -294,6 +295,13 @@ static int tps6586x_rtc_probe(struct pla goto fail_rtc_register; } disable_irq(rtc->irq); + + ret = rtc_register_device(rtc->rtc); + if (ret) { + dev_err(&pdev->dev, "RTC device register: ret %d\n", ret); + goto fail_rtc_register; + } + return 0; fail_rtc_register: