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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 5BE63C433FE for ; Thu, 9 Sep 2021 12:51:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 431F261104 for ; Thu, 9 Sep 2021 12:51:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1354468AbhIIMwm (ORCPT ); Thu, 9 Sep 2021 08:52:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:56650 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1355348AbhIIMpT (ORCPT ); Thu, 9 Sep 2021 08:45:19 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id D3928613AC; Thu, 9 Sep 2021 11:56:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631188561; bh=9OHCdoC2zS+9x1XGxywbtw+tpN9NjKwHyk7WhAEKvX4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rk9kexFUpftqxn6H64T5UR93WUH1bi8SexK7SyRgnOs09auqo44Ed9MZX3AmCcnQG ubr5ih9JaMrtgV432lc5Qc7Rynjl685FmnADro8r87P2c0wzWJ6D3ikfGZJT5IfqBa I60fgb0aJSdNKe7yAK6aTn3BbUR+v9IEdilduOlPniEWJt5Nqu9pTyt48UcRdneOby ADMDroW3SqzRMZ4BJZA95wxAuqmaMglgXZCdkmkHgZ1RZzztyG++S9P0ofJnWyE1Dq tf8zv7ftTvOJ613vbX1UCgo1WKTJ7uHAM2KoFZYpuA0EoeJDJUn3fNLTHbMPSX4AW1 3Zhmec96qJHEw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Desmond Cheong Zhi Xi , syzbot+66264bf2fd0476be7e6c@syzkaller.appspotmail.com, Marcel Holtmann , Sasha Levin , linux-bluetooth@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 5.4 043/109] Bluetooth: skip invalid hci_sync_conn_complete_evt Date: Thu, 9 Sep 2021 07:54:00 -0400 Message-Id: <20210909115507.147917-43-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210909115507.147917-1-sashal@kernel.org> References: <20210909115507.147917-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netdev@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 e8e7f108b016..82e42d8e2ea0 100644 --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -4202,6 +4202,21 @@ 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