From patchwork Sat Mar 26 07:09:28 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ying Hsu X-Patchwork-Id: 12792261 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 B75D9C433EF for ; Sat, 26 Mar 2022 07:09:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231738AbiCZHLL (ORCPT ); Sat, 26 Mar 2022 03:11:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54946 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229882AbiCZHLK (ORCPT ); Sat, 26 Mar 2022 03:11:10 -0400 Received: from mail-pg1-x529.google.com (mail-pg1-x529.google.com [IPv6:2607:f8b0:4864:20::529]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0D2C026D121 for ; Sat, 26 Mar 2022 00:09:35 -0700 (PDT) Received: by mail-pg1-x529.google.com with SMTP id c11so8166006pgu.11 for ; Sat, 26 Mar 2022 00:09:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=aY7Qm3duZzz4/ANMI52LqTxkdMO5YlOW9+CWZKbNUDQ=; b=I05Mab032aTpoTeimJ2ZOfF1xo8R9P0uXq5lBgIRm+2ywDCJ7TRBiojiTa2Sl4OyrW ENUppUa56EY/52pmYjwVkvLFtLbIrXRiqjns6jQiDFovrx+lkvG4JwIweL0YU8mdQjko 42818OZdanjVU+H50AQcXJKz2sx+o0LKLoabM= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=aY7Qm3duZzz4/ANMI52LqTxkdMO5YlOW9+CWZKbNUDQ=; b=iITdoDvUmOx8AQT5oBW+J4472DZEwWAdD7WVWL9e7o/mEsKpAAGp5H992QzVZ2jml7 Qej6A1ce6b4KrHUorkjlEX3O668Y9egFCFFC1BaxK26w7r40Sp/KAZRGfK7DehQh95hy RYQqf7yEhNzB4+UZLJ2BYUUfnB8nByrduEGvIqxWZeOaH2otu2rOlbXjB3N7fOxRyLnD tEvf3tu8hRNay67K7Z8H0V6wULlPQXQQqJNhLP8SCiAzkA8tnN2cstX4pgFcZhe5/994 IK/NVA1DSiXmfIoIC/lm2dxC7NgZWbgCZVH/F/3dBEBX4zmoSDQgUxQPbT2c8ZLyu0BF hTvQ== X-Gm-Message-State: AOAM531UvCvB0xJrgE1e7PeONoFxxvmTunio1Dq822emwpA3zgHPvP2A KVmZvHQBpblPRbFoeQF4ivp0Nw== X-Google-Smtp-Source: ABdhPJxLT1yAk+YxicpfYCc3ehIfT2Bhk4TwGg5YlmuZKXxtcXZhn3FYsvFWkuU6byOwpgW5/SuX6g== X-Received: by 2002:a05:6a00:815:b0:4fb:e46:511c with SMTP id m21-20020a056a00081500b004fb0e46511cmr7185978pfk.54.1648278574592; Sat, 26 Mar 2022 00:09:34 -0700 (PDT) Received: from localhost (0.223.81.34.bc.googleusercontent.com. [34.81.223.0]) by smtp.gmail.com with UTF8SMTPSA id j6-20020a17090a588600b001c699d77503sm7565679pji.2.2022.03.26.00.09.31 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 26 Mar 2022 00:09:33 -0700 (PDT) From: Ying Hsu To: marcel@holtmann.org Cc: chromeos-bluetooth-upstreaming@chromium.org, Ying Hsu , syzbot+2bef95d3ab4daa10155b@syzkaller.appspotmail.com, Joseph Hwang , "David S. Miller" , Desmond Cheong Zhi Xi , Jakub Kicinski , Johan Hedberg , Luiz Augusto von Dentz , Paolo Abeni , linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH v2] Bluetooth: fix dangling sco_conn and use-after-free in sco_sock_timeout Date: Sat, 26 Mar 2022 07:09:28 +0000 Message-Id: <20220326070853.v2.1.I67f8ad854ac2f48701902bfb34d6e2070011b779@changeid> X-Mailer: git-send-email 2.35.1.1021.g381101b075-goog MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-bluetooth@vger.kernel.org Connecting the same socket twice consecutively in sco_sock_connect() could lead to a race condition where two sco_conn objects are created but only one is associated with the socket. If the socket is closed before the SCO connection is established, the timer associated with the dangling sco_conn object won't be canceled. As the sock object is being freed, the use-after-free problem happens when the timer callback function sco_sock_timeout() accesses the socket. Here's the call trace: dump_stack+0x107/0x163 ? refcount_inc+0x1c/ print_address_description.constprop.0+0x1c/0x47e ? refcount_inc+0x1c/0x7b kasan_report+0x13a/0x173 ? refcount_inc+0x1c/0x7b check_memory_region+0x132/0x139 refcount_inc+0x1c/0x7b sco_sock_timeout+0xb2/0x1ba process_one_work+0x739/0xbd1 ? cancel_delayed_work+0x13f/0x13f ? __raw_spin_lock_init+0xf0/0xf0 ? to_kthread+0x59/0x85 worker_thread+0x593/0x70e kthread+0x346/0x35a ? drain_workqueue+0x31a/0x31a ? kthread_bind+0x4b/0x4b ret_from_fork+0x1f/0x30 Link: https://syzkaller.appspot.com/bug?extid=2bef95d3ab4daa10155b Reported-by: syzbot+2bef95d3ab4daa10155b@syzkaller.appspotmail.com Fixes: e1dee2c1de2b ("Bluetooth: fix repeated calls to sco_sock_kill") Signed-off-by: Ying Hsu Reviewed-by: Joseph Hwang --- Tested this commit using a C reproducer on qemu-x86_64 for 8 hours. Changes in v2: - Adding Link, Reported-by, and Fixes tags in comment. net/bluetooth/sco.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) diff --git a/net/bluetooth/sco.c b/net/bluetooth/sco.c index 8eabf41b2993..380c63194736 100644 --- a/net/bluetooth/sco.c +++ b/net/bluetooth/sco.c @@ -574,19 +574,24 @@ static int sco_sock_connect(struct socket *sock, struct sockaddr *addr, int alen addr->sa_family != AF_BLUETOOTH) return -EINVAL; - if (sk->sk_state != BT_OPEN && sk->sk_state != BT_BOUND) - return -EBADFD; + lock_sock(sk); + if (sk->sk_state != BT_OPEN && sk->sk_state != BT_BOUND) { + err = -EBADFD; + goto done; + } - if (sk->sk_type != SOCK_SEQPACKET) - return -EINVAL; + if (sk->sk_type != SOCK_SEQPACKET) { + err = -EINVAL; + goto done; + } hdev = hci_get_route(&sa->sco_bdaddr, &sco_pi(sk)->src, BDADDR_BREDR); - if (!hdev) - return -EHOSTUNREACH; + if (!hdev) { + err = -EHOSTUNREACH; + goto done; + } hci_dev_lock(hdev); - lock_sock(sk); - /* Set destination address and psm */ bacpy(&sco_pi(sk)->dst, &sa->sco_bdaddr);