From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 8D3A55581F7; Thu, 17 Sep 2026 15:30:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789659019; cv=none; b=f8LSjMkHxIHfeCHcI3R1AZRBPV6GBUQxrlDqFnDfBNaZQUZnClibDkaU9CZLzcnTlY9E8eFUDQR4IEUrApaowxc+Y7WXe9zl2vFtrktH5uK0sojgr+NtZ4xgDhsdwtzhhr8S9yC0vbnqOIG/dGqXetPDfuEus6nTHWLZsZ+PK2U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789659019; c=relaxed/simple; bh=v4u/J6vhtp9Ra/GILAjsGyTetLN03G4K7Q6MPPsGwtk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=fnmF8OrCKKq1sFZRIiWRKp2ESUr2Zng3R6qahnSSyYoRy/EJT+d/Iw4XjtxL8Ebn0Kl/dyxFlBq2kouAmT2AKsZac8lw6XbfCnMrB/G7DPhI4r02KQQPjzXzHlJ/XDFWO6xuulWOz2PVcUJ3mmT3f2l9/x/o+ow5HJ6Aigl0y7M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=L1x5o2Yq; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="L1x5o2Yq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DC0821F00899; Thu, 17 Sep 2026 15:30:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789659007; bh=w5ktI75tKqhjKXR1z08PXK7p+nJbxHT34gLtTObmXik=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=L1x5o2YqrMggnn0XgxAlDABiDqE52Taqo0uLulANZlMK5jD8RWC1CqiVAz5ENle0E vWrbxBP7W5g8wDX9EZHOrWGIakMuqlqAI9wuDh2E9uXJPl5dIzVSDd+DlXAxcfV000 hMdjvt9wOSgw1QzaLeWU986z7JQVbsLYoy0ufB6U= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+14ce1b05b7d5a989abbe@syzkaller.appspotmail.com, Aleksandr Nogikh , Luiz Augusto von Dentz , Sasha Levin Subject: [PATCH 7.2 111/733] Bluetooth: hci_core: Fix race condition during device registration Date: Thu, 17 Sep 2026 16:06:59 +0100 Message-ID: <20260917151353.749823532@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260917151350.597953846@linuxfoundation.org> References: <20260917151350.597953846@linuxfoundation.org> User-Agent: quilt/0.69 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 7.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Aleksandr Nogikh [ Upstream commit 57938bbdb9bf7fd41cbd5cd509ec10c4b22bec18 ] In hci_register_dev(), the power_on work item is queued to hdev->req_workqueue before initializing hdev->adv_monitors_idr and registering the MSFT extension via msft_register(). For devices marked with quirks such as HCI_QUIRK_RAW_DEVICE, the HCI_UNCONFIGURED flag is set on the device. When the power_on work item runs concurrently on another CPU, hci_power_on() detects that the device is unconfigured and immediately invokes hci_dev_do_close(), which calls msft_do_close(). Concurrently, msft_register() allocates the msft structure and exposes it to hdev->msft_data prior to calling mutex_init(&msft->filter_lock). If msft_do_close() executes while hdev->msft_data is already assigned but the mutex has not yet been initialized, mutex_lock(&msft->filter_lock) operates on an uninitialized mutex, triggering a DEBUG_LOCKS warning: DEBUG_LOCKS_WARN_ON(lock->magic != lock) WARNING: kernel/locking/mutex.c:625 at __mutex_lock_common kernel/locking/mutex.c:625 [inline] WARNING: kernel/locking/mutex.c:625 at __mutex_lock+0x12d8/0x1550 kernel/locking/mutex.c:821 ... Call Trace: msft_do_close+0x308/0x7b0 net/bluetooth/msft.c:693 hci_dev_close_sync+0x86b/0x10a0 net/bluetooth/hci_sync.c:5522 hci_dev_do_close net/bluetooth/hci_core.c:499 [inline] hci_power_on+0x32c/0x750 net/bluetooth/hci_core.c:937 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0x92d/0xe10 kernel/workqueue.c:3486 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Fix this by moving the queue_work() call in hci_register_dev() to after idr_init(&hdev->adv_monitors_idr) and msft_register(hdev) so that device structures and extensions are fully initialized before asynchronous tasks can access them. Additionally, assign hdev->msft_data in msft_register() only after mutex_init(&msft->filter_lock) has completed. Fixes: 9e14606d8f38 ("Bluetooth: msft: Extended monitor tracking by address filter") Assisted-by: Gemini:gemini-3.7-flash Gemini:gemini-3.1-pro-preview syzbot Reported-by: syzbot+14ce1b05b7d5a989abbe@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=14ce1b05b7d5a989abbe Link: https://syzkaller.appspot.com/ai_job?id=2bc9e8aa-ca6d-43e2-be2c-fd5d9f649d7e Signed-off-by: Aleksandr Nogikh Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin --- net/bluetooth/hci_core.c | 4 ++-- net/bluetooth/msft.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c index f346505c3f88c..f747492da5f66 100644 --- a/net/bluetooth/hci_core.c +++ b/net/bluetooth/hci_core.c @@ -2629,11 +2629,11 @@ int hci_register_dev(struct hci_dev *hdev) if (error) BT_WARN("register suspend notifier failed error:%d\n", error); - queue_work(hdev->req_workqueue, &hdev->power_on); - idr_init(&hdev->adv_monitors_idr); msft_register(hdev); + queue_work(hdev->req_workqueue, &hdev->power_on); + return id; err_wqueue: diff --git a/net/bluetooth/msft.c b/net/bluetooth/msft.c index ded68568e6c9b..d9dd722db3ebd 100644 --- a/net/bluetooth/msft.c +++ b/net/bluetooth/msft.c @@ -769,8 +769,8 @@ void msft_register(struct hci_dev *hdev) INIT_LIST_HEAD(&msft->handle_map); INIT_LIST_HEAD(&msft->address_filters); - hdev->msft_data = msft; mutex_init(&msft->filter_lock); + hdev->msft_data = msft; } void msft_release(struct hci_dev *hdev) -- 2.53.0