From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3CCB41494DB; Thu, 5 Sep 2024 10:04:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725530696; cv=none; b=bACqrRWUtZXOQGYfuKHK6MVFYT0HjHYtXajUcotGGscHK2DLqw1oUbOConLEpwSBIKQfZCtTVr1YeMY2yDKbost5fa1i9t1ykXQEfMPJqUkx6IOFeDw+K2xfoXfrcvy7k0yPHneQ3ccKNNK9f4RkVZsxR/pA7iN2jwzkyAPoieI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725530696; c=relaxed/simple; bh=iT1gwhw5hv92AUB0jLT3gff/lgF865d5r73hCneGCOE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=gTApYfGWL78t5NjkyAZuqpoPEfzWbffkI1brO0nIa6/dYiBaPtfHPZyL1oke5FvuIOSE5qDoTK2/QGF9UWFbq1gO8vaVtS0SbKG8GodM3OZLuX/mU+CapJqw5pH3zAzEEIWa0v1oRgSfejc8lYpzB62oAmVbYnVne9+yOBFkJwE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=W6pKHIhZ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="W6pKHIhZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B4669C4CEC3; Thu, 5 Sep 2024 10:04:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1725530696; bh=iT1gwhw5hv92AUB0jLT3gff/lgF865d5r73hCneGCOE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=W6pKHIhZ25Wnx4xnllU+jOAhiJ4RBcUu80NFPyDCGBTCvq5ip74oEeBCdE9uABBHT SWjmJhrMVxKT0kHSJuSt49nDJWjM21MyICozOR+zzpeLJHZ7I+SMPwjSLbtcGjkMbf ATPPjirSJcy22esYt6x6te/53FnX85/Shymmhcl4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Luiz Augusto von Dentz Subject: [PATCH 6.1 095/101] Bluetooth: SCO: Fix possible circular locking dependency on sco_connect_cfm Date: Thu, 5 Sep 2024 11:42:07 +0200 Message-ID: <20240905093719.839986185@linuxfoundation.org> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20240905093716.075835938@linuxfoundation.org> References: <20240905093716.075835938@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Luiz Augusto von Dentz commit 9a8ec9e8ebb5a7c0cfbce2d6b4a6b67b2b78e8f3 upstream. This attempts to fix the following trace: ====================================================== WARNING: possible circular locking dependency detected 6.3.0-rc2-g0b93eeba4454 #4703 Not tainted ------------------------------------------------------ kworker/u3:0/46 is trying to acquire lock: ffff888001fd9130 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}, at: sco_connect_cfm+0x118/0x4a0 but task is already holding lock: ffffffff831e3340 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_sync_conn_complete_evt+0x1ad/0x3d0 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (hci_cb_list_lock){+.+.}-{3:3}: __mutex_lock+0x13b/0xcc0 hci_sync_conn_complete_evt+0x1ad/0x3d0 hci_event_packet+0x55c/0x7c0 hci_rx_work+0x34c/0xa00 process_one_work+0x575/0x910 worker_thread+0x89/0x6f0 kthread+0x14e/0x180 ret_from_fork+0x2b/0x50 -> #1 (&hdev->lock){+.+.}-{3:3}: __mutex_lock+0x13b/0xcc0 sco_sock_connect+0xfc/0x630 __sys_connect+0x197/0x1b0 __x64_sys_connect+0x37/0x50 do_syscall_64+0x42/0x90 entry_SYSCALL_64_after_hwframe+0x70/0xda -> #0 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}: __lock_acquire+0x18cc/0x3740 lock_acquire+0x151/0x3a0 lock_sock_nested+0x32/0x80 sco_connect_cfm+0x118/0x4a0 hci_sync_conn_complete_evt+0x1e6/0x3d0 hci_event_packet+0x55c/0x7c0 hci_rx_work+0x34c/0xa00 process_one_work+0x575/0x910 worker_thread+0x89/0x6f0 kthread+0x14e/0x180 ret_from_fork+0x2b/0x50 other info that might help us debug this: Chain exists of: sk_lock-AF_BLUETOOTH-BTPROTO_SCO --> &hdev->lock --> hci_cb_list_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(hci_cb_list_lock); lock(&hdev->lock); lock(hci_cb_list_lock); lock(sk_lock-AF_BLUETOOTH-BTPROTO_SCO); *** DEADLOCK *** 4 locks held by kworker/u3:0/46: #0: ffff8880028d1130 ((wq_completion)hci0#2){+.+.}-{0:0}, at: process_one_work+0x4c0/0x910 #1: ffff8880013dfde0 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work+0x4c0/0x910 #2: ffff8880025d8070 (&hdev->lock){+.+.}-{3:3}, at: hci_sync_conn_complete_evt+0xa6/0x3d0 #3: ffffffffb79e3340 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_sync_conn_complete_evt+0x1ad/0x3d0 Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Greg Kroah-Hartman --- net/bluetooth/sco.c | 69 ++++++++++++++++++++++++++++++---------------------- 1 file changed, 40 insertions(+), 29 deletions(-) --- a/net/bluetooth/sco.c +++ b/net/bluetooth/sco.c @@ -239,27 +239,41 @@ static int sco_chan_add(struct sco_conn return err; } -static int sco_connect(struct hci_dev *hdev, struct sock *sk) +static int sco_connect(struct sock *sk) { struct sco_conn *conn; struct hci_conn *hcon; + struct hci_dev *hdev; int err, type; BT_DBG("%pMR -> %pMR", &sco_pi(sk)->src, &sco_pi(sk)->dst); + hdev = hci_get_route(&sco_pi(sk)->dst, &sco_pi(sk)->src, BDADDR_BREDR); + if (!hdev) + return -EHOSTUNREACH; + + hci_dev_lock(hdev); + if (lmp_esco_capable(hdev) && !disable_esco) type = ESCO_LINK; else type = SCO_LINK; if (sco_pi(sk)->setting == BT_VOICE_TRANSPARENT && - (!lmp_transp_capable(hdev) || !lmp_esco_capable(hdev))) - return -EOPNOTSUPP; + (!lmp_transp_capable(hdev) || !lmp_esco_capable(hdev))) { + err = -EOPNOTSUPP; + goto unlock; + } hcon = hci_connect_sco(hdev, type, &sco_pi(sk)->dst, sco_pi(sk)->setting, &sco_pi(sk)->codec); - if (IS_ERR(hcon)) - return PTR_ERR(hcon); + if (IS_ERR(hcon)) { + err = PTR_ERR(hcon); + goto unlock; + } + + hci_dev_unlock(hdev); + hci_dev_put(hdev); conn = sco_conn_add(hcon); if (!conn) { @@ -267,13 +281,15 @@ static int sco_connect(struct hci_dev *h return -ENOMEM; } - /* Update source addr of the socket */ - bacpy(&sco_pi(sk)->src, &hcon->src); - err = sco_chan_add(conn, sk, NULL); if (err) return err; + lock_sock(sk); + + /* Update source addr of the socket */ + bacpy(&sco_pi(sk)->src, &hcon->src); + if (hcon->state == BT_CONNECTED) { sco_sock_clear_timer(sk); sk->sk_state = BT_CONNECTED; @@ -282,6 +298,13 @@ static int sco_connect(struct hci_dev *h sco_sock_set_timer(sk, sk->sk_sndtimeo); } + release_sock(sk); + + return err; + +unlock: + hci_dev_unlock(hdev); + hci_dev_put(hdev); return err; } @@ -561,7 +584,6 @@ static int sco_sock_connect(struct socke { struct sockaddr_sco *sa = (struct sockaddr_sco *) addr; struct sock *sk = sock->sk; - struct hci_dev *hdev; int err; BT_DBG("sk %p", sk); @@ -570,37 +592,26 @@ static int sco_sock_connect(struct socke addr->sa_family != AF_BLUETOOTH) return -EINVAL; - lock_sock(sk); - if (sk->sk_state != BT_OPEN && sk->sk_state != BT_BOUND) { - err = -EBADFD; - goto done; - } + if (sk->sk_state != BT_OPEN && sk->sk_state != BT_BOUND) + return -EBADFD; - if (sk->sk_type != SOCK_SEQPACKET) { + 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) { - err = -EHOSTUNREACH; - goto done; - } - hci_dev_lock(hdev); + lock_sock(sk); /* Set destination address and psm */ bacpy(&sco_pi(sk)->dst, &sa->sco_bdaddr); + release_sock(sk); - err = sco_connect(hdev, sk); - hci_dev_unlock(hdev); - hci_dev_put(hdev); + err = sco_connect(sk); if (err) - goto done; + return err; + + lock_sock(sk); err = bt_sock_wait_state(sk, BT_CONNECTED, sock_sndtimeo(sk, flags & O_NONBLOCK)); -done: release_sock(sk); return err; }