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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no 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 D735BC43603 for ; Tue, 17 Dec 2019 00:58:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A9F8E206D3 for ; Tue, 17 Dec 2019 00:58:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727030AbfLQA6W (ORCPT ); Mon, 16 Dec 2019 19:58:22 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:34892 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726783AbfLQAvj (ORCPT ); Mon, 16 Dec 2019 19:51:39 -0500 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1ih15I-0003Kl-Hs; Tue, 17 Dec 2019 00:51:32 +0000 Received: from ben by deadeye with local (Exim 4.93-RC7) (envelope-from ) id 1ih15I-0005YV-BL; Tue, 17 Dec 2019 00:51:32 +0000 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Johan Hovold" Date: Tue, 17 Dec 2019 00:46:48 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 074/136] USB: serial: ti_usb_3410_5052: fix port-close races In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.80-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Johan Hovold commit 6f1d1dc8d540a9aa6e39b9cb86d3a67bbc1c8d8d upstream. Fix races between closing a port and opening or closing another port on the same device which could lead to a failure to start or stop the shared interrupt URB. The latter could potentially cause a use-after-free or worse in the completion handler on driver unbind. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Johan Hovold Signed-off-by: Ben Hutchings --- drivers/usb/serial/ti_usb_3410_5052.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) --- a/drivers/usb/serial/ti_usb_3410_5052.c +++ b/drivers/usb/serial/ti_usb_3410_5052.c @@ -542,7 +542,6 @@ static void ti_close(struct usb_serial_p struct ti_port *tport; int port_number; int status; - int do_unlock; unsigned long flags; tdev = usb_get_serial_data(port->serial); @@ -569,16 +568,13 @@ static void ti_close(struct usb_serial_p "%s - cannot send close port command, %d\n" , __func__, status); - /* if mutex_lock is interrupted, continue anyway */ - do_unlock = !mutex_lock_interruptible(&tdev->td_open_close_lock); + mutex_lock(&tdev->td_open_close_lock); --tport->tp_tdev->td_open_port_count; - if (tport->tp_tdev->td_open_port_count <= 0) { + if (tport->tp_tdev->td_open_port_count == 0) { /* last port is closed, shut down interrupt urb */ usb_kill_urb(port->serial->port[0]->interrupt_in_urb); - tport->tp_tdev->td_open_port_count = 0; } - if (do_unlock) - mutex_unlock(&tdev->td_open_close_lock); + mutex_unlock(&tdev->td_open_close_lock); }