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=-6.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 D9432C7618B for ; Thu, 25 Jul 2019 12:59:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BC35921951 for ; Thu, 25 Jul 2019 12:59:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729112AbfGYM7q convert rfc822-to-8bit (ORCPT ); Thu, 25 Jul 2019 08:59:46 -0400 Received: from coyote.holtmann.net ([212.227.132.17]:50657 "EHLO mail.holtmann.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725901AbfGYM7q (ORCPT ); Thu, 25 Jul 2019 08:59:46 -0400 Received: from marcel-macbook.fritz.box (p5B3D2BA7.dip0.t-ipconnect.de [91.61.43.167]) by mail.holtmann.org (Postfix) with ESMTPSA id A8EA1CEC82; Thu, 25 Jul 2019 15:08:20 +0200 (CEST) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 12.4 \(3445.104.11\)) Subject: Re: [PATCH] Bluetooth: hci_uart: check for missing tty operations in protocol handlers From: Marcel Holtmann In-Reply-To: <20190725120909.31235-1-vdronov@redhat.com> Date: Thu, 25 Jul 2019 14:59:42 +0200 Cc: Johan Hedberg , linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org, Suraj Sumangala , Frederic Danis , Loic Poulain , Balakrishna Godavarthi , syzkaller@googlegroups.com Content-Transfer-Encoding: 8BIT Message-Id: <2E234F47-724D-4CFB-93B5-48E5BDA6F230@holtmann.org> References: <20190725120909.31235-1-vdronov@redhat.com> To: Vladis Dronov X-Mailer: Apple Mail (2.3445.104.11) Sender: linux-bluetooth-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-bluetooth@vger.kernel.org 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