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=-8.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 448F7C37122 for ; Tue, 22 Jan 2019 02:08:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0F99920870 for ; Tue, 22 Jan 2019 02:08:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="jpsaCZIA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726825AbfAVCIE (ORCPT ); Mon, 21 Jan 2019 21:08:04 -0500 Received: from mail-it1-f194.google.com ([209.85.166.194]:51647 "EHLO mail-it1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726648AbfAVCID (ORCPT ); Mon, 21 Jan 2019 21:08:03 -0500 Received: by mail-it1-f194.google.com with SMTP id w18so19280197ite.1 for ; Mon, 21 Jan 2019 18:08:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:mime-version:content-disposition :user-agent; bh=uOAmpQ8tpNpwSSe+DsGaIGiIc0oKaybcAwK6+WCbZcw=; b=jpsaCZIAqTHZdmFnwF/0lMYHzTVvGF/JksLa305TJQ6Qv8Jz4X5dK6KaDRWyXICuTw UBU6p3fIr4FfYYeikWlaH3wmbpsSTFgzJVgz9naGL/sqcniFQTST24FImgimyq58AOCK 6T87GhqF19DLUGTy9duceB549cu3mUivZQkY1U/fdlj9+F4uvLlisPd6tdiswz+c8+59 RaRvtY+VrLm9IE2kuxrfR3tkRt0BldfV9ST6/2vngPucE3B0+P22phmun6ugjJUkjM8H +UwsJ+OGGDjbbMr8wkqnL+GKssDFJXooSFhj3dSHZbJi+ZZLQWOgyyvkxDzZlVeUo0+i F9ZQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:mime-version :content-disposition:user-agent; bh=uOAmpQ8tpNpwSSe+DsGaIGiIc0oKaybcAwK6+WCbZcw=; b=iPqkHcP0qo2GAM2Gpq5RPOS7wIQwV/4UoUQlmPlzmOUr+P9cdShoUZAJ/kbfYWIMwX dN1+S0N6uTEfvAtLroUsGSI2y8Pmrc8oDu93fDNjp9Hj3uqy9p7gFaFGA/JemIA1R1vv wTiRETbjlsLQyRz1ocKo+TSuWx6pYtCu7anf8KunquhBCqAzka4AYfOi/h1MpV2lPdRF mNSCOVZxXJWM+5bPzmVNWuAJYlZN3MagdtVVj9zNFPHfL8ZgP1b3cVWN2UxziTDhA1+p wcQModvvuYx1+CDOXoglQ2bSTqABhVSMmxQj/dhSAgAumMgi9kszPjVb/7ozpCKOolL3 i1Qg== X-Gm-Message-State: AHQUAubH2V3x3kr6C9AHmEwWI0ky299PweoinFTLU7YIbc23ZVcSzHL0 ivYdYOduwX7gk+La6COzY4c= X-Google-Smtp-Source: ALg8bN4z7Fy1crnJkxvo5I/44XE050nGIY8Wu6jfWIslfcUQmi5W4HLfk+HOee4d2/K61qG+oFaO7g== X-Received: by 2002:a24:88:: with SMTP id 130mr1116696ita.92.1548122882689; Mon, 21 Jan 2019 18:08:02 -0800 (PST) Received: from ubu-Virtual-Machine (66-188-57-61.dhcp.bycy.mi.charter.com. [66.188.57.61]) by smtp.gmail.com with ESMTPSA id w24sm5912958ioc.11.2019.01.21.18.08.01 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 21 Jan 2019 18:08:02 -0800 (PST) Date: Mon, 21 Jan 2019 21:07:59 -0500 From: Kimberly Brown To: Michael Kelley , Long Li , Sasha Levin , Dexuan Cui , Stephen Hemminger Cc: "K. Y. Srinivasan" , Haiyang Zhang , devel@linuxdriverproject.org, linux-kernel@vger.kernel.org Subject: [PATCH] Drivers: hv: vmbus: Add mutex lock to channel show functions Message-ID: <20190122020759.GA4054@ubu-Virtual-Machine> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The channel level "_show" functions are vulnerable to race conditions. Add a mutex lock and unlock around the call to the channel level "_show" functions in vmbus_chan_attr_show(). This problem was discussed here: https://lkml.org/lkml/2018/10/18/830 Signed-off-by: Kimberly Brown --- drivers/hv/vmbus_drv.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index 403fee01572c..e8189bc168da 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -1414,6 +1414,7 @@ static ssize_t vmbus_chan_attr_show(struct kobject *kobj, = container_of(attr, struct vmbus_chan_attribute, attr); const struct vmbus_channel *chan = container_of(kobj, struct vmbus_channel, kobj); + ssize_t ret; if (!attribute->show) return -EIO; @@ -1421,7 +1422,10 @@ static ssize_t vmbus_chan_attr_show(struct kobject *kobj, if (chan->state != CHANNEL_OPENED_STATE) return -EINVAL; - return attribute->show(chan, buf); + mutex_lock(&vmbus_connection.channel_mutex); + ret = attribute->show(chan, buf); + mutex_unlock(&vmbus_connection.channel_mutex); + return ret; } static const struct sysfs_ops vmbus_chan_sysfs_ops = { -- 2.17.1