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=-20.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 C4080C433FE for ; Mon, 20 Sep 2021 17:06:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AFD4961B27 for ; Mon, 20 Sep 2021 17:06:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346578AbhITRHv (ORCPT ); Mon, 20 Sep 2021 13:07:51 -0400 Received: from mail.kernel.org ([198.145.29.99]:54482 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235055AbhITRFG (ORCPT ); Mon, 20 Sep 2021 13:05:06 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 363F261373; Mon, 20 Sep 2021 16:54:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1632156887; bh=3jNSMhNgV8VpDGHADUKhdFPeiU4t88d5JG+96o8RGMk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SbDFI2yHIiCUY09wbhYrmQoH+bwfnhM00YIWOJoxxHAXrQF5XSXDZbibe34DqtU8m ZVviqJ/+LAgdxSq4i+uX7i32N/aXEv5kJ+rmFl87E4qHS4KAUL2cbEBlbJSTlqTdvz 0WToPIFg9WAp3xPlTcIl9NIYpgdTVQaMwvnTpdk0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+66264bf2fd0476be7e6c@syzkaller.appspotmail.com, Desmond Cheong Zhi Xi , Marcel Holtmann , Sasha Levin Subject: [PATCH 4.9 131/175] Bluetooth: skip invalid hci_sync_conn_complete_evt Date: Mon, 20 Sep 2021 18:43:00 +0200 Message-Id: <20210920163922.363374245@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210920163918.068823680@linuxfoundation.org> References: <20210920163918.068823680@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Desmond Cheong Zhi Xi [ Upstream commit 92fe24a7db751b80925214ede43f8d2be792ea7b ] Syzbot reported a corrupted list in kobject_add_internal [1]. This happens when multiple HCI_EV_SYNC_CONN_COMPLETE event packets with status 0 are sent for the same HCI connection. This causes us to register the device more than once which corrupts the kset list. As this is forbidden behavior, we add a check for whether we're trying to process the same HCI_EV_SYNC_CONN_COMPLETE event multiple times for one connection. If that's the case, the event is invalid, so we report an error that the device is misbehaving, and ignore the packet. Link: https://syzkaller.appspot.com/bug?extid=66264bf2fd0476be7e6c [1] Reported-by: syzbot+66264bf2fd0476be7e6c@syzkaller.appspotmail.com Tested-by: syzbot+66264bf2fd0476be7e6c@syzkaller.appspotmail.com Signed-off-by: Desmond Cheong Zhi Xi Signed-off-by: Marcel Holtmann Signed-off-by: Sasha Levin --- net/bluetooth/hci_event.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c index 44eeb27e341a..f9484755a9ba 100644 --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -3761,6 +3761,21 @@ static void hci_sync_conn_complete_evt(struct hci_dev *hdev, switch (ev->status) { case 0x00: + /* The synchronous connection complete event should only be + * sent once per new connection. Receiving a successful + * complete event when the connection status is already + * BT_CONNECTED means that the device is misbehaving and sent + * multiple complete event packets for the same new connection. + * + * Registering the device more than once can corrupt kernel + * memory, hence upon detecting this invalid event, we report + * an error and ignore the packet. + */ + if (conn->state == BT_CONNECTED) { + bt_dev_err(hdev, "Ignoring connect complete event for existing connection"); + goto unlock; + } + conn->handle = __le16_to_cpu(ev->handle); conn->state = BT_CONNECTED; conn->type = ev->link_type; -- 2.30.2