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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 4B043C433E0 for ; Tue, 23 Mar 2021 15:06:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 054BF6198C for ; Tue, 23 Mar 2021 15:06:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232598AbhCWPFn (ORCPT ); Tue, 23 Mar 2021 11:05:43 -0400 Received: from coyote.holtmann.net ([212.227.132.17]:57628 "EHLO mail.holtmann.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232384AbhCWPFR (ORCPT ); Tue, 23 Mar 2021 11:05:17 -0400 Received: from marcel-macbook.holtmann.net (p4fefce19.dip0.t-ipconnect.de [79.239.206.25]) by mail.holtmann.org (Postfix) with ESMTPSA id 1A97FCECE4; Tue, 23 Mar 2021 16:12:53 +0100 (CET) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 14.0 \(3654.60.0.2.21\)) Subject: Re: [PATCH v2] Bluetooth: check for zapped sk before connecting From: Marcel Holtmann In-Reply-To: <20210323163141.v2.1.I6c4306f6e8ba3ccc9106067d4eb70092f8cb2a49@changeid> Date: Tue, 23 Mar 2021 16:05:13 +0100 Cc: linux-bluetooth , CrosBT Upstreaming , Archie Pusaka , syzbot+abfc0f5e668d4099af73@syzkaller.appspotmail.com, Alain Michaud , Abhishek Pandit-Subedi , Guenter Roeck , "David S. Miller" , Jakub Kicinski , Johan Hedberg , Luiz Augusto von Dentz , LKML , netdev@vger.kernel.org Content-Transfer-Encoding: 7bit Message-Id: <94F81995-4C43-4788-9EF1-54FB3C905784@holtmann.org> References: <20210323163141.v2.1.I6c4306f6e8ba3ccc9106067d4eb70092f8cb2a49@changeid> To: Archie Pusaka X-Mailer: Apple Mail (2.3654.60.0.2.21) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Archie, > There is a possibility of receiving a zapped sock on > l2cap_sock_connect(). This could lead to interesting crashes, one > such case is tearing down an already tore l2cap_sock as is happened > with this call trace: > > __dump_stack lib/dump_stack.c:15 [inline] > dump_stack+0xc4/0x118 lib/dump_stack.c:56 > register_lock_class kernel/locking/lockdep.c:792 [inline] > register_lock_class+0x239/0x6f6 kernel/locking/lockdep.c:742 > __lock_acquire+0x209/0x1e27 kernel/locking/lockdep.c:3105 > lock_acquire+0x29c/0x2fb kernel/locking/lockdep.c:3599 > __raw_spin_lock_bh include/linux/spinlock_api_smp.h:137 [inline] > _raw_spin_lock_bh+0x38/0x47 kernel/locking/spinlock.c:175 > spin_lock_bh include/linux/spinlock.h:307 [inline] > lock_sock_nested+0x44/0xfa net/core/sock.c:2518 > l2cap_sock_teardown_cb+0x88/0x2fb net/bluetooth/l2cap_sock.c:1345 > l2cap_chan_del+0xa3/0x383 net/bluetooth/l2cap_core.c:598 > l2cap_chan_close+0x537/0x5dd net/bluetooth/l2cap_core.c:756 > l2cap_chan_timeout+0x104/0x17e net/bluetooth/l2cap_core.c:429 > process_one_work+0x7e3/0xcb0 kernel/workqueue.c:2064 > worker_thread+0x5a5/0x773 kernel/workqueue.c:2196 > kthread+0x291/0x2a6 kernel/kthread.c:211 > ret_from_fork+0x4e/0x80 arch/x86/entry/entry_64.S:604 > > Signed-off-by: Archie Pusaka > Reported-by: syzbot+abfc0f5e668d4099af73@syzkaller.appspotmail.com > Reviewed-by: Alain Michaud > Reviewed-by: Abhishek Pandit-Subedi > Reviewed-by: Guenter Roeck > --- > > Changes in v2: > * Modify locking order for better visibility > > net/bluetooth/l2cap_sock.c | 8 ++++++++ > 1 file changed, 8 insertions(+) patch has been applied to bluetooth-next tree. Regards Marcel