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 082B7C7EE22 for ; Mon, 1 May 2023 09:51:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232306AbjEAJvb (ORCPT ); Mon, 1 May 2023 05:51:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45660 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232284AbjEAJv0 (ORCPT ); Mon, 1 May 2023 05:51:26 -0400 Received: from mail-pj1-x102d.google.com (mail-pj1-x102d.google.com [IPv6:2607:f8b0:4864:20::102d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 30E5BE4A; Mon, 1 May 2023 02:51:24 -0700 (PDT) Received: by mail-pj1-x102d.google.com with SMTP id 98e67ed59e1d1-24e01ba9e03so517082a91.1; Mon, 01 May 2023 02:51:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1682934683; x=1685526683; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=wAyKklJP4RAwcGyHLElFHWzPziFPamUTZVBn88mFHEM=; b=GqMfQC7PQxWSJHUrzTkIrUFwPjo7AQsDMlPtX/wojI4kRyPoU76VlXhPhhdiWO2liC M1Y5g5GAs0zZLbMPhMZnI5FkpQ2WCSHTYZ3mqeftXv/E7ReZJOyGSksVcK4kvfbXG8N5 GmgMAXvRjp9iE5FQl3/M4krfXy8951z3lHS5+DK9cKhcX+DFLC3eowFmt7twD7yU14+K YDNV1J+//dvM0DHYoKBmtLshIcTTakJsr7tDmbpkhFzI7A7Ox2INx6MUn4eXx7voZlE6 7cq5cS9ggipGlO+YFALA7YmsWyxxwtqk1jHXjO/1utZCrMII0jf38EZ2JKSUr/E1CTrc i6eg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1682934683; x=1685526683; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=wAyKklJP4RAwcGyHLElFHWzPziFPamUTZVBn88mFHEM=; b=flKWZVthQgECi7qZxI+TGlRc63Wqm+XloM+2DrzY1FKs2vMRqQDG4G9yxrZSM1mWmd we9ysisSAOJtXXpOvPJ48JnRBpzFjJIqKYRMtkw8nU0xOmynnyFU/pPXyLj7ucYaDP/x W3Bm5QLuc1w1Azi2dikaIeJZ0xgJHF8Cx22w5apg0F0cAJplqG3GhvjuH6aq2iLRWuJi iAwqCADH+N2wV5Td9HTPW1jGVwWpU4UoiZtuv4VN4Ga096N3+W9rOmT6BGc93lFkhKw2 S73kSZEqpnXvCtuAPRaNNJ97/kSQRlPvueP4zL/MaXUfRqFkSP/Pwonvda+rGgrWHyTC wLiA== X-Gm-Message-State: AC+VfDwURUefprrKj7xQqpCQ+poRxPM1TyugkaZmWq7r0jHz1+MeqnIG ml5nCo0UsUyA4+Ox0GWfW7w= X-Google-Smtp-Source: ACHHUZ7bXlwoLS0yE+UKf5JmSxUljwc8fOGS1fiKev+OTVuxC2eEjE3byoVXgpmu5zrdQewi4e6A0w== X-Received: by 2002:a17:90a:bc89:b0:24e:134e:96db with SMTP id x9-20020a17090abc8900b0024e134e96dbmr619501pjr.22.1682934683254; Mon, 01 May 2023 02:51:23 -0700 (PDT) Received: from [183.173.17.116] ([183.173.17.116]) by smtp.gmail.com with ESMTPSA id h16-20020a17090aea9000b00247164c1947sm5180481pjz.0.2023.05.01.02.51.20 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 01 May 2023 02:51:22 -0700 (PDT) Message-ID: Date: Mon, 1 May 2023 17:51:20 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.10.0 Subject: Re: [BUG][RESEND] Bluetooth: L2CAP: possible data race in __sco_sock_close() Content-Language: en-US To: Luiz Augusto von Dentz Cc: marcel@holtmann.org, johan.hedberg@gmail.com, "David S. Miller" , edumazet@google.com, Jakub Kicinski , pabeni@redhat.com, linux-bluetooth@vger.kernel.org, netdev@vger.kernel.org, Linux Kernel , baijiaju1990@outlook.com References: From: Tuo Li In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Thanks for your reply and interests. Our static analysis tool is still to be improved, and any feedback on it would be appreciated. On 2023/4/29 5:24, Luiz Augusto von Dentz wrote: > Hi, > > On Fri, Apr 28, 2023 at 3:27 AM Li Tuo wrote: >> Hello, >> >> Our static analysis tool finds a possible data race in the l2cap protocol >> in Linux 6.3.0-rc7: >> >> In most calling contexts, the variable sk->sk_socket is accessed >> with holding the lock sk->sk_callback_lock. Here is an example: >> >> l2cap_sock_accept() --> Line 346 in net/bluetooth/l2cap_sock.c >> bt_accept_dequeue() --> Line 368 in net/bluetooth/l2cap_sock.c >> sock_graft() --> Line 240 in net/bluetooth/af_bluetooth.c >> write_lock_bh(&sk->sk_callback_lock); --> Line 2081 in include/net/sock.h (Lock sk->sk_callback_lock) >> sk_set_socket() --> Line 2084 in include/net/sock.h >> sk->sk_socket = sock; --> Line 2054 in include/net/sock.h (Access sk->sk_socket) >> >> However, in the following calling context: >> >> sco_sock_shutdown() --> Line 1227 in net/bluetooth/sco.c >> __sco_sock_close() --> Line 1243 in net/bluetooth/sco.c >> BT_DBG(..., sk->sk_socket); --> Line 431 in net/bluetooth/sco.c (Access sk->sk_socket) >> >> the variable sk->sk_socket is accessed without holding the lock >> sk->sk_callback_lock, and thus a data race may occur. >> >> Reported-by: BassCheck > Need to check in detail what it means to hold the sk_callback_lock, > btw is this static analysis tool of yours something public that we can > use in our CI to detect these problems? > >