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=-2.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 EA14EC43603 for ; Wed, 18 Dec 2019 12:37:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BC80B2146E for ; Wed, 18 Dec 2019 12:37:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="gMiz6Nra" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726932AbfLRMhV (ORCPT ); Wed, 18 Dec 2019 07:37:21 -0500 Received: from mail-pj1-f52.google.com ([209.85.216.52]:55007 "EHLO mail-pj1-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726545AbfLRMhV (ORCPT ); Wed, 18 Dec 2019 07:37:21 -0500 Received: by mail-pj1-f52.google.com with SMTP id ep17so817528pjb.4; Wed, 18 Dec 2019 04:37:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=to:cc:from:subject:message-id:date:user-agent:mime-version :content-transfer-encoding:content-language; bh=SDfBkN3VJf5jvQD3fKgAU+xo/Y2l5f5r8EL8+ID85KA=; b=gMiz6Nraeacz1pgHx0sxX6cGe+A7DVbn1+tUGN1ReWgzlEZQVWWz1fPBXsaQdg6WX5 AI4NGJA4oIJEhh8sXOlWxXjpJeQiacSdCVMsTvw7k79WrNrfZdyvF01ekd/99pIuNSk7 l6DFFgcQCfjaGV7ovXfpdi4oOaLE6fGAwLXmAtAecubjMYQ2LGma8xFNtzcIVQHxymR0 AZbswJYHVYVsGIcV8bNKpboO0lYKI/jZ7xguig4cSQTVtnJoSmKj2JCBK4wUmVTTmPsm SBrwtimlBVItCSWQDudgNrEGMagz41l1pFQehSZjTbXZA/IXsi0vtdMZIRdcbku3ivJl gRew== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:to:cc:from:subject:message-id:date:user-agent :mime-version:content-transfer-encoding:content-language; bh=SDfBkN3VJf5jvQD3fKgAU+xo/Y2l5f5r8EL8+ID85KA=; b=H1HNSn1ffMAHGfu0S7MYoAtfUK0wTLR5xZOlYYZVeL+XAhOMiAdi7rCC5wAiplx6LH Ohpz/Zp+AG7cfFeD3Zm2t/oskFEiRZ8zcdW7DSkAVjHY+94An3+kaAUY1Gg4F3f3auuN hmFgAfXItNHIbpWug+MaxeCCsHe2Xu7ocdyxUTRbSNH6U/CS7f+4Fv/81eZgMWi+o/0W gdINfDBVD2+vrWT2AwH8O6sLpRpt2zLLneNNI0BgqtGEWkHriCzoKFQawmF2qYxTkejF i5lVlqJXdlEE9WiaruGEtWUGFzMUAiRL7E4pUPv2dCGizXiRQqBLlSbdQ9w/lM5f4wiU YXQA== X-Gm-Message-State: APjAAAWZWYuB7TwVfafyhuSGd0GDFqzqWeZIt0Qe1mQm0NnoIq9z7K0X qkVByfwGbultYI0fjXbSmgSaWHmsrRr57g== X-Google-Smtp-Source: APXvYqwKHlr/DWW77+DCtxg0yDJBmtZIIAMafU7Trkih5YEuKsYAAz8HhqBoS+Zjq3bON0Kb2FCR5w== X-Received: by 2002:a17:902:a70c:: with SMTP id w12mr2529732plq.124.1576672640391; Wed, 18 Dec 2019 04:37:20 -0800 (PST) Received: from ?IPv6:2402:f000:1:1501:200:5efe:166.111.139.103? ([2402:f000:1:1501:200:5efe:a66f:8b67]) by smtp.gmail.com with ESMTPSA id x4sm3236162pfx.68.2019.12.18.04.37.18 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 18 Dec 2019 04:37:19 -0800 (PST) To: marcel@holtmann.org, johan.hedberg@gmail.com Cc: linux-bluetooth@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org From: Jia-Ju Bai Subject: [BUG] net: bluetooth: a possible sleep-in-atomic-context bug in disconnect_all_peers() Message-ID: Date: Wed, 18 Dec 2019 20:37:19 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.9.1 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The kernel module may sleep while holding a spinlock. The function call path (from bottom to top) in Linux 4.19 is: net/bluetooth/l2cap_core.c, 840:     mutex_lock in l2cap_get_ident net/bluetooth/l2cap_core.c, 1402:     l2cap_get_ident in l2cap_send_disconn_req net/bluetooth/l2cap_core.c, 736:     l2cap_send_disconn_req in l2cap_chan_close net/bluetooth/6lowpan.c, 1053:     l2cap_chan_close in disconnect_all_peers net/bluetooth/6lowpan.c, 1051:     spin_lock in disconnect_all_peers mutex_lock() can sleep at runtime. I am not sure how to properly fix this possible bug, so I only report it. This bug is found by a static analysis tool STCheck written by myself. Best wishes, Jia-Ju Bai