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=-14.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 BFEFFC11F69 for ; Wed, 30 Jun 2021 07:24:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A217C61CD5 for ; Wed, 30 Jun 2021 07:24:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232870AbhF3H1H (ORCPT ); Wed, 30 Jun 2021 03:27:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44052 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232636AbhF3H1F (ORCPT ); Wed, 30 Jun 2021 03:27:05 -0400 Received: from mail-pj1-x1035.google.com (mail-pj1-x1035.google.com [IPv6:2607:f8b0:4864:20::1035]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 739C0C061766; Wed, 30 Jun 2021 00:24:36 -0700 (PDT) Received: by mail-pj1-x1035.google.com with SMTP id g4so1203772pjk.0; Wed, 30 Jun 2021 00:24:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=Zr28EiN6VTW0jAQmgor6rRPBvukZW16zav6uSZ93P58=; b=sEgaC4BLwiy3yFg8V7Dr/bWalMnVwBo7USwEiT8Gijwpggx3qwwlcPd8kMw8oyItuP XpRr9R6h9jzg82/eF9Qi9i15Wpo8++Wdv4d4ctpVQOkq/JgW+M+yUv1u2aiwaerW5XOa znqqETtPTFQGMsRWZOrvgSzsD3u/wgjat66ra6GaK/02P4HRrwZQQ8jCL38LBbDFdrXd 4oOYejiNrJOdk5eAV5osPa9WdRL57bIrrTKaWth6f2vabex0A9Z7uYwwufhUJkud5EoS X6A/VUWPg+GbDvSpAsAYnIe5MW906XcYroqkgwK2GDyvf/N9ab0KS3cB4hWp/E1R5Lyy XqFQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=Zr28EiN6VTW0jAQmgor6rRPBvukZW16zav6uSZ93P58=; b=YkYhygIzKespZU8YYfplG3G3p+SKMXnWhEmWFwwWdrIpy4GnBcXKAQ0NssXHNvxxCz IduMtrTLwdny7l774Ey8ImZ9QZ74F9tXBlLG4iUotvcvIRXF4rlmmW9ynUhE5FjfEYOO ycntqK8iS0NM36Y/F6FG0wIQfb+tlGrbtCJoMjCn8ebgqJ5LTFtTsgpC2RSy3DFXSAoJ xqot7eDT9yYYFe30wSqzvuykR6coh6NtzpNdmuExMPuZqektTNqJMbWFHc58nv8Mroa7 W/7LfniZzEnnP98Hpt+v0YP3q73+cdAw0ztOKKMASlLXCWRlaTZTceq+n1TfS9GLf+zj d7sw== X-Gm-Message-State: AOAM533F0Aijy69+wjsxU49H8rWMjduZSkuHlcBnct28LtfcRBM/swHT DOK1VqI8eXkyRbPK9QwB8Lo= X-Google-Smtp-Source: ABdhPJytYzBb9+z1b9aEN4qsdHsyEkthrIv5PCGbcvop4yE5z+/opRU4aIS9xcKvN7RiWK8y2vrypw== X-Received: by 2002:a17:902:eccb:b029:127:9520:ac96 with SMTP id a11-20020a170902eccbb02901279520ac96mr30710868plh.70.1625037875840; Wed, 30 Jun 2021 00:24:35 -0700 (PDT) Received: from [192.168.0.118] ([103.242.196.99]) by smtp.gmail.com with ESMTPSA id s123sm20152132pfb.78.2021.06.30.00.24.32 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 30 Jun 2021 00:24:35 -0700 (PDT) Subject: Re: [PATCH] char: tpm: vtpm_proxy: Fix race in init To: Jarkko Sakkinen Cc: peterhuewe@gmx.de, jgg@ziepe.ca, linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org, ldv-project@linuxtesting.org, andrianov@ispras.ru References: <20210623132226.140341-1-saubhik.mukherjee@gmail.com> <20210629172700.yxqnedbayumo5f24@kernel.org> <20210629210524.hze6yb23pps3flnv@kernel.org> From: Saubhik Mukherjee Message-ID: <2b7d8d44-791e-284a-a700-5465fbc2c100@gmail.com> Date: Wed, 30 Jun 2021 12:54:30 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <20210629210524.hze6yb23pps3flnv@kernel.org> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 6/30/21 2:35 AM, Jarkko Sakkinen wrote: > On Tue, Jun 29, 2021 at 08:27:00PM +0300, Jarkko Sakkinen wrote: >> On Wed, Jun 23, 2021 at 06:52:26PM +0530, Saubhik Mukherjee wrote: >>> vtpm_module_init calls vtpmx_init which calls misc_register. The file >>> operations callbacks are registered. So, vtpmx_fops_ioctl can execute in >>> parallel with rest of vtpm_module_init. vtpmx_fops_ioctl calls >>> vtpmx_ioc_new_dev, which calls vtpm_proxy_create_device, which calls >>> vtpm_proxy_work_start, which could read uninitialized workqueue. >>> >>> To avoid this, create workqueue before vtpmx init. >>> >>> Found by Linux Driver Verification project (linuxtesting.org). >>> >>> Signed-off-by: Saubhik Mukherjee >>> --- >>> drivers/char/tpm/tpm_vtpm_proxy.c | 19 +++++++++---------- >>> 1 file changed, 9 insertions(+), 10 deletions(-) >>> >>> diff --git a/drivers/char/tpm/tpm_vtpm_proxy.c b/drivers/char/tpm/tpm_vtpm_proxy.c >>> index 91c772e38bb5..225dfa026a8f 100644 >>> --- a/drivers/char/tpm/tpm_vtpm_proxy.c >>> +++ b/drivers/char/tpm/tpm_vtpm_proxy.c >>> @@ -697,23 +697,22 @@ static int __init vtpm_module_init(void) >>> { >>> int rc; >>> >>> - rc = vtpmx_init(); >>> - if (rc) { >>> - pr_err("couldn't create vtpmx device\n"); >>> - return rc; >>> - } >>> - >>> workqueue = create_workqueue("tpm-vtpm"); >>> if (!workqueue) { >>> pr_err("couldn't create workqueue\n"); >>> - rc = -ENOMEM; >>> - goto err_vtpmx_cleanup; >>> + return -ENOMEM; >>> + } >>> + >>> + rc = vtpmx_init(); >>> + if (rc) { >>> + pr_err("couldn't create vtpmx device\n"); >>> + goto err_destroy_workqueue; >>> } >>> >>> return 0; >>> >>> -err_vtpmx_cleanup: >>> - vtpmx_cleanup(); >>> +err_destroy_workqueue: >>> + destroy_workqueue(workqueue); >>> >>> return rc; >>> } >>> -- >>> 2.30.2 >>> >>> >> >> Reviewed-by: Jarkko Sakkinen > > Taking reviewed-by back. > > You're lacking fixes tag. Please re-send with one. > > /Jarkko > Thank you for noticing. I sent the patch containing the Fixes tag in reply to your last message. (https://lkml.org/lkml/2021/6/30/104)