From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-1733193-1527156525-2-16744515789971816760 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.25, MAILING_LIST_MULTI -1, RCVD_IN_DNSWL_HI -5, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='US', FromHeader='org', MailFrom='org' X-Spam-charsets: plain='UTF-8' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=fm2; t= 1527156525; b=YH9fhR8GPogjrPQmYD/E7Ug4sBC7GoEL0emKR5/m1rnWASdO2v KnRcYcjffWZYOsv4AmQ5JORyk3z6R2Ff8G2h2EdVmNt20zCdfzxtdMIA5O81KgtG sMGiP+AePHNpeO5GoHH+kvUkVm/hjKec6k5PcAtMZSdJ6KGLZBSnGTp8tmS+eXUj R30kOHKhqhjkhhtAP2v3VFoTVZ9h0NqM2qKcP+mnqG5we0hIMK/NJm4THqqcD8IA czGC50CL0kTe0toEMpnKYrcPIbJVTUGjxtt9+xvVTpMuo3sGt9bXB3POvxqhxEwG cuk53gs4t/cNkNwriUFFRUQWSYGZLA7tbxnA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-type:sender :list-id; s=fm2; t=1527156525; bh=oRc0IIRgHHCAlEBJD1ai8pc+RdWGSf Qnp3amYbopjww=; b=gzG/9XZlSvukQ1nevzPG4r7kvtfPXtAsGmTbDLfirmz0ON Ge0omM5DPy6gOCW9ICEXzWCzFY42YXUTr3WLSgaKIvUjbjtDHfJgMnLVze7D4J+O KujIxz1xwE+MtLQCj9rA6cxwTLsZ84zVADuCisXlHNpDOwL4qyUZgbwXi8wBrUlW jt6vFFgGgs26g0M2f0agJ+f4K0Ae169xS5gkNgMAOGS88ky/Fg8UXSr1H7Ss6x8G lts64KiVMOrOM6XnopxRxNJGmUOhmPFiT31sz2sGE4Vzsf/jWPPFluXAQvs+PqJv 5RuvCXLbjd+WvQVgLhcOrrP28w+G+R3KBvDMUBXQ== ARC-Authentication-Results: i=1; mx3.messagingengine.com; arc=none (no signatures found); dkim=pass (1024-bit rsa key sha256) header.d=kernel.org header.i=@kernel.org header.b=yipjeYuc x-bits=1024 x-keytype=rsa x-algorithm=sha256 x-selector=default; dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-cm=none score=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 Authentication-Results: mx3.messagingengine.com; arc=none (no signatures found); dkim=pass (1024-bit rsa key sha256) header.d=kernel.org header.i=@kernel.org header.b=yipjeYuc x-bits=1024 x-keytype=rsa x-algorithm=sha256 x-selector=default; dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-cm=none score=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 X-ME-VSCategory: clean X-CM-Envelope: MS4wfH0qRWcALN+X7QMhnE9F7we6MzzOC1hZ3Fp7tf8AxPx13hnIm85OCAmnKlwNbegBYqc3ojNHqawvb/Skzh0rOAh/nOma+qx5wVxRLzmpkcUM8OPGqVRx CvZQnKZr8TIPn1GnCR9hBmruAfIZhg/QXoOMlIfk26/PCCP15N27n00CaNLYQ2REalKcAEtPYfpvAlN0erc+X7uFEEXcH3m8QSKbBb5CsqAOmmhDzNxOJDSU X-CM-Analysis: v=2.3 cv=Tq3Iegfh c=1 sm=1 tr=0 a=UK1r566ZdBxH71SXbqIOeA==:117 a=UK1r566ZdBxH71SXbqIOeA==:17 a=IkcTkHD0fZMA:10 a=VUJBJC2UJ8kA:10 a=P-IC7800AAAA:8 a=yMhMjlubAAAA:8 a=ag1SF4gXAAAA:8 a=_reXzBdDsLP_B_R58xkA:9 a=QEXdDO2ut3YA:10 a=d3PnA9EDa4IxuAV0gXij:22 a=Yupwre4RP9_Eg_Bd0iYG:22 X-ME-CMScore: 0 X-ME-CMCategory: none Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1031425AbeEXKI1 (ORCPT ); Thu, 24 May 2018 06:08:27 -0400 Received: from mail.kernel.org ([198.145.29.99]:55100 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1031229AbeEXKGF (ORCPT ); Thu, 24 May 2018 06:06:05 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexandre Belloni , Sasha Levin Subject: [PATCH 4.16 160/161] rtc: rp5c01: fix possible race condition Date: Thu, 24 May 2018 11:39:45 +0200 Message-Id: <20180524093037.431976454@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180524093018.331893860@linuxfoundation.org> References: <20180524093018.331893860@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alexandre Belloni [ Upstream commit bcdd559268039d8340d38fa58668393596e29fdc ] The probe function is not allowed to fail after registering the RTC 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* */ Switch to devm_rtc_allocate_device/rtc_register_device to register the rtc as late as possible. Signed-off-by: Alexandre Belloni Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/rtc/rtc-rp5c01.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) --- a/drivers/rtc/rtc-rp5c01.c +++ b/drivers/rtc/rtc-rp5c01.c @@ -249,16 +249,24 @@ static int __init rp5c01_rtc_probe(struc platform_set_drvdata(dev, priv); - rtc = devm_rtc_device_register(&dev->dev, "rtc-rp5c01", &rp5c01_rtc_ops, - THIS_MODULE); + rtc = devm_rtc_allocate_device(&dev->dev); if (IS_ERR(rtc)) return PTR_ERR(rtc); + + rtc->ops = &rp5c01_rtc_ops; + priv->rtc = rtc; error = sysfs_create_bin_file(&dev->dev.kobj, &priv->nvram_attr); if (error) return error; + error = rtc_register_device(rtc); + if (error) { + sysfs_remove_bin_file(&dev->dev.kobj, &priv->nvram_attr); + return error; + } + return 0; }