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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2EB67C433F5 for ; Fri, 29 Apr 2022 16:53:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1379346AbiD2Q4r (ORCPT ); Fri, 29 Apr 2022 12:56:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56732 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1379341AbiD2Q4q (ORCPT ); Fri, 29 Apr 2022 12:56:46 -0400 Received: from mail-wm1-x32b.google.com (mail-wm1-x32b.google.com [IPv6:2a00:1450:4864:20::32b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 88D50DA6EB for ; Fri, 29 Apr 2022 09:53:26 -0700 (PDT) Received: by mail-wm1-x32b.google.com with SMTP id m62so4939665wme.5 for ; Fri, 29 Apr 2022 09:53:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=message-id:date:mime-version:user-agent:subject:content-language:to :cc:references:from:in-reply-to:content-transfer-encoding; bh=gF0XSQXvhEerOtZQE67Fv/RM3gJgfWvh3o2fwzeA8OY=; b=hELuasXky3HZCxMFNpSgD5FdIPEXNRdTxdKAxbkPN05aGII+4JoICUbBkMAlUTurAQ L6rq3PGkAHUUnTQyc77gwoC8jb5v/4xaWEPra41O5oJAGpi+LgDune8CEKlVMPUtHY5P O/eEEHdM+XZr2XIG5aK+qgjTUCrdJ2kHBbMajpFupqsvaP9vRtzwB0Uz4+Gf5AIA7gk1 KPjzG5830EmbPOv1yaRsPTilWcM1cjJVjRJl5rDGhF8BxYtXAaIZptSN0yV0YbnkLHQr wwI4EMsxsemAwyf5szkcjYyIShJriszMFsxF7nBAvq0Ooi0nz6OicKvtuEQr7uHCvJX5 ePBA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=gF0XSQXvhEerOtZQE67Fv/RM3gJgfWvh3o2fwzeA8OY=; b=SYMBIFC7cGc052MD2vanHIyNt55YC++19melzMh0q3QTOnj0XhtxDfiMSxdNAHwbXh wZ2NFIwiJustajGSoeDSMS0V6POxdvwlWJtuzPdoalXS4KOJp8ezjr//5RN3WXszcTQx 3xVOZmNQNohfODjrVsruRYceSm/lALYLLLb2+u4n4qNw5yXTvNyEg76VEa2tDJt//CLS 8GWtXNXKOz0iscHkUKdiM6tBiUD6UvZz/DoWEt++jVlw/lfTM/8QCtpzswIMVZmjoaLZ dA5BmlB5jf+JTbT3+JhutF+Em5qhAy/DSGx0PE7vjjGQ1cBIPPpOqhgjrO/09eK2x1uB 45rQ== X-Gm-Message-State: AOAM533WJ2UhiM8SBUvbMARcbtG002q7IvJNEaPNfIc4IIDYoQvUHlfn lLH64/0IjMlX9SXkWMHvLlmT/g== X-Google-Smtp-Source: ABdhPJx4wGrPBGJPFmNxW8tuM/QQdlgSJgzr9IKK/k91ySYvrwxQTmHM+rRPDy4KJY2hydWvfeXNAg== X-Received: by 2002:a05:600c:3547:b0:393:eee3:39df with SMTP id i7-20020a05600c354700b00393eee339dfmr3998609wmq.181.1651251205114; Fri, 29 Apr 2022 09:53:25 -0700 (PDT) Received: from [192.168.86.34] (cpc90716-aztw32-2-0-cust825.18-1.cable.virginm.net. [86.26.103.58]) by smtp.googlemail.com with ESMTPSA id o11-20020a05600c4fcb00b00391447f7fd4sm3642655wmq.24.2022.04.29.09.53.23 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 29 Apr 2022 09:53:24 -0700 (PDT) Message-ID: Date: Fri, 29 Apr 2022 17:53:23 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.7.0 Subject: Re: [PATCH] misc: fastrpc: fix an incorrect NULL check on list iterator Content-Language: en-US To: Xiaomeng Tong Cc: amahesh@qti.qualcomm.com, arnd@arndb.de, gregkh@linuxfoundation.org, jorge.ramirez-ortiz@linaro.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org References: <20220327062202.5720-1-xiam0nd.tong@gmail.com> From: Srinivas Kandagatla In-Reply-To: <20220327062202.5720-1-xiam0nd.tong@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On 27/03/2022 07:22, Xiaomeng Tong wrote: > The bug is here: > if (!buf) { > > The list iterator value 'buf' will *always* be set and non-NULL > by list_for_each_entry(), so it is incorrect to assume that the > iterator value will be NULL if the list is empty (in this case, the > check 'if (!buf) {' will always be false and never exit expectly). > > To fix the bug, use a new variable 'iter' as the list iterator, > while use the original variable 'buf' as a dedicated pointer to > point to the found element. > > Cc: stable@vger.kernel.org > Fixes: 2419e55e532de ("misc: fastrpc: add mmap/unmap support") > Signed-off-by: Xiaomeng Tong LGTM, Reviewed-by: Srinivas Kandagatla > --- > drivers/misc/fastrpc.c | 9 +++++---- > 1 file changed, 5 insertions(+), 4 deletions(-) > > diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c > index aa1682b94a23..45aaf54a7560 100644 > --- a/drivers/misc/fastrpc.c > +++ b/drivers/misc/fastrpc.c > @@ -1353,17 +1353,18 @@ static int fastrpc_req_munmap_impl(struct fastrpc_user *fl, > struct fastrpc_req_munmap *req) > { > struct fastrpc_invoke_args args[1] = { [0] = { 0 } }; > - struct fastrpc_buf *buf, *b; > + struct fastrpc_buf *buf = NULL, *iter, *b; > struct fastrpc_munmap_req_msg req_msg; > struct device *dev = fl->sctx->dev; > int err; > u32 sc; > > spin_lock(&fl->lock); > - list_for_each_entry_safe(buf, b, &fl->mmaps, node) { > - if ((buf->raddr == req->vaddrout) && (buf->size == req->size)) > + list_for_each_entry_safe(iter, b, &fl->mmaps, node) { > + if ((iter->raddr == req->vaddrout) && (iter->size == req->size)) { > + buf = iter; > break; > - buf = NULL; > + } > } > spin_unlock(&fl->lock); >