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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 253BAC7618B for ; Thu, 25 Jul 2019 14:26:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EF0D621901 for ; Thu, 25 Jul 2019 14:26:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388321AbfGYO0b (ORCPT ); Thu, 25 Jul 2019 10:26:31 -0400 Received: from mx1.redhat.com ([209.132.183.28]:38346 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388214AbfGYO0b (ORCPT ); Thu, 25 Jul 2019 10:26:31 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 890383083047; Thu, 25 Jul 2019 14:26:30 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.21]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 6FBA91001B09; Thu, 25 Jul 2019 14:26:30 +0000 (UTC) Received: from zmail21.collab.prod.int.phx2.redhat.com (zmail21.collab.prod.int.phx2.redhat.com [10.5.83.24]) by colo-mx.corp.redhat.com (Postfix) with ESMTP id 3132CE160; Thu, 25 Jul 2019 14:26:30 +0000 (UTC) Date: Thu, 25 Jul 2019 10:26:29 -0400 (EDT) From: Vladis Dronov To: Marcel Holtmann Cc: Johan Hedberg , linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org, Suraj Sumangala , Frederic Danis , Loic Poulain , Balakrishna Godavarthi , syzkaller@googlegroups.com Message-ID: <74627941.4546902.1564064789961.JavaMail.zimbra@redhat.com> In-Reply-To: <2E234F47-724D-4CFB-93B5-48E5BDA6F230@holtmann.org> References: <20190725120909.31235-1-vdronov@redhat.com> <2E234F47-724D-4CFB-93B5-48E5BDA6F230@holtmann.org> Subject: Re: [PATCH] Bluetooth: hci_uart: check for missing tty operations in protocol handlers MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Originating-IP: [10.43.2.29, 10.4.195.24] Thread-Topic: Bluetooth: hci_uart: check for missing tty operations in protocol handlers Thread-Index: gnD96eYXODpIBBKB1hw8FR4695NsjA== X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.46]); Thu, 25 Jul 2019 14:26:30 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, Marcel, > why is this one hidden behind CONFIG_PM? The general baud rate changes are > independent of runtime power management support. hci_bcm calls hci_uart_set_flow_control() only from functions hidden behind #ifdef-CONFIG_PM (surely this can change in the future), and so without CONFIG_PM set it cannot hit the bug (as of now). So I've hidden the check for tiocm[gs]et() behind #ifdef-CONFIG_PM too. If you tell me it is better to remove this #ifdef, I'll remove it. > And I would introduce a bool hci_uart_has_tiocm_support(struct hci_uart *) > helper. Great, I will add it to the v2 fix. I guess a good place for it is hci_ldisc.c, near hci_uart_set_flow_control(), isn't it? Best regards, Vladis Dronov | Red Hat, Inc. | The Core Kernel | Senior Software Engineer ----- Original Message ----- > From: "Marcel Holtmann" > To: "Vladis Dronov" > Cc: "Johan Hedberg" , linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org, "Suraj > Sumangala" , "Frederic Danis" , "Loic Poulain" > , "Balakrishna Godavarthi" , syzkaller@googlegroups.com > Sent: Thursday, July 25, 2019 2:59:42 PM > Subject: Re: [PATCH] Bluetooth: hci_uart: check for missing tty operations in protocol handlers > > Hi Vladis, > > > Certain ttys operations (pty_unix98_ops) lack tiocmget() and tiocmset() > > functions which are called by the certain HCI UART protocols (hci_ath, > > hci_bcm, hci_intel, hci_mrvl, hci_qca) via hci_uart_set_flow_control() > > or directly. This leads to an execution at NULL and can be triggered by > > an unprivileged user. Fix this by adding a check for the missing tty > > operations to the protocols which use them. > > > > This fixes CVE-2019-10207. > > > > Link: > > https://syzkaller.appspot.com/bug?id=1b42faa2848963564a5b1b7f8c837ea7b55ffa50 > > Reported-by: syzbot+79337b501d6aa974d0f6@syzkaller.appspotmail.com > > Cc: stable@vger.kernel.org # v2.6.36+ > > Fixes: b3190df62861 ("Bluetooth: Support for Atheros AR300x serial chip") > > Fixes: 118612fb9165 ("Bluetooth: hci_bcm: Add suspend/resume PM functions") > > Fixes: ff2895592f0f ("Bluetooth: hci_intel: Add Intel baudrate > > configuration support") > > Fixes: 162f812f23ba ("Bluetooth: hci_uart: Add Marvell support") > > Fixes: fa9ad876b8e0 ("Bluetooth: hci_qca: Add support for Qualcomm > > Bluetooth chip wcn3990") > > Signed-off-by: Vladis Dronov > > --- > > drivers/bluetooth/hci_ath.c | 3 +++ > > drivers/bluetooth/hci_bcm.c | 5 +++++ > > drivers/bluetooth/hci_intel.c | 3 +++ > > drivers/bluetooth/hci_mrvl.c | 3 +++ > > drivers/bluetooth/hci_qca.c | 4 ++++ > > 5 files changed, 18 insertions(+) > > > > diff --git a/drivers/bluetooth/hci_ath.c b/drivers/bluetooth/hci_ath.c > > index a55be205b91a..99df8a13e47e 100644 > > --- a/drivers/bluetooth/hci_ath.c > > +++ b/drivers/bluetooth/hci_ath.c > > @@ -98,6 +98,9 @@ static int ath_open(struct hci_uart *hu) > > > > BT_DBG("hu %p", hu); > > > > + if (!hu->tty->driver->ops->tiocmget || !hu->tty->driver->ops->tiocmset) > > + return -ENOTSUPP; > > + > > ath = kzalloc(sizeof(*ath), GFP_KERNEL); > > if (!ath) > > return -ENOMEM; > > diff --git a/drivers/bluetooth/hci_bcm.c b/drivers/bluetooth/hci_bcm.c > > index 8905ad2edde7..8c3e09cc341c 100644 > > --- a/drivers/bluetooth/hci_bcm.c > > +++ b/drivers/bluetooth/hci_bcm.c > > @@ -406,6 +406,11 @@ static int bcm_open(struct hci_uart *hu) > > > > bt_dev_dbg(hu->hdev, "hu %p", hu); > > > > +#ifdef CONFIG_PM > > + if (!hu->tty->driver->ops->tiocmget || !hu->tty->driver->ops->tiocmset) > > + return -ENOTSUPP; > > +#endif > > + > > why is this one hidden behind CONFIG_PM? The general baud rate changes are > independent of runtime power management support. > > And I would introduce a bool hci_uart_has_tiocm_support(struct hci_uart *) > helper. > > Regards > > Marcel