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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B51D9C4332F for ; Wed, 19 Oct 2022 08:58:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232036AbiJSI6I (ORCPT ); Wed, 19 Oct 2022 04:58:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49060 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231949AbiJSI5E (ORCPT ); Wed, 19 Oct 2022 04:57:04 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 051EC193EE; Wed, 19 Oct 2022 01:53:03 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 20F016186B; Wed, 19 Oct 2022 08:52:00 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 34B58C433C1; Wed, 19 Oct 2022 08:51:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1666169519; bh=lpoonZ2TlVs0iMtpGE/VUE4JhkN9JsM8I1mBYYrYK/M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hv1P2c1d6yK2aanKopY2Cd7BD4nIncDvU2xdaTF6zk+px/W/zQBE8vqmIe/oXWZuq AO5ggzH+Io5MbO1JBM85rfsqX9pxANId0dhMNIYKXF+/ZU9K0gPOXJ1jKL0tFlkvP7 A3mZW9oCZIJia03Wj0wEuWjrScpDFWapcTyJovPA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+844c7bf1b1aa4119c5de@syzkaller.appspotmail.com, Tetsuo Handa , Luiz Augusto von Dentz , Sasha Levin Subject: [PATCH 6.0 274/862] Bluetooth: avoid hci_dev_test_and_set_flag() in mgmt_init_hdev() Date: Wed, 19 Oct 2022 10:26:01 +0200 Message-Id: <20221019083302.138874417@linuxfoundation.org> X-Mailer: git-send-email 2.38.0 In-Reply-To: <20221019083249.951566199@linuxfoundation.org> References: <20221019083249.951566199@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Tetsuo Handa [ Upstream commit f74ca25d6d6629ffd4fd80a1a73037253b57d06b ] syzbot is again reporting attempt to cancel uninitialized work at mgmt_index_removed() [1], for setting of HCI_MGMT flag from mgmt_init_hdev() from hci_mgmt_cmd() from hci_sock_sendmsg() can race with testing of HCI_MGMT flag from mgmt_index_removed() from hci_sock_bind() due to lack of serialization via hci_dev_lock(). Since mgmt_init_hdev() is called with mgmt_chan_list_lock held, we can safely split hci_dev_test_and_set_flag() into hci_dev_test_flag() and hci_dev_set_flag(). Thus, in order to close this race, set HCI_MGMT flag after INIT_DELAYED_WORK() completed. This is a local fix based on mgmt_chan_list_lock. Lack of serialization via hci_dev_lock() might be causing different race conditions somewhere else. But a global fix based on hci_dev_lock() should deserve a future patch. Link: https://syzkaller.appspot.com/bug?extid=844c7bf1b1aa4119c5de Reported-by: syzbot+844c7bf1b1aa4119c5de@syzkaller.appspotmail.com Signed-off-by: Tetsuo Handa Fixes: 3f2893d3c142986a ("Bluetooth: don't try to cancel uninitialized works at mgmt_index_removed()") Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin --- net/bluetooth/mgmt.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c index 72e6595a71cc..3d1cd0666968 100644 --- a/net/bluetooth/mgmt.c +++ b/net/bluetooth/mgmt.c @@ -1050,7 +1050,7 @@ static void discov_off(struct work_struct *work) static void mgmt_init_hdev(struct sock *sk, struct hci_dev *hdev) { - if (hci_dev_test_and_set_flag(hdev, HCI_MGMT)) + if (hci_dev_test_flag(hdev, HCI_MGMT)) return; BT_INFO("MGMT ver %d.%d", MGMT_VERSION, MGMT_REVISION); @@ -1065,6 +1065,8 @@ static void mgmt_init_hdev(struct sock *sk, struct hci_dev *hdev) * it */ hci_dev_clear_flag(hdev, HCI_BONDABLE); + + hci_dev_set_flag(hdev, HCI_MGMT); } static int read_controller_info(struct sock *sk, struct hci_dev *hdev, -- 2.35.1