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 95F9BC282DD for ; Wed, 8 Jan 2020 19:50:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6DDC32070E for ; Wed, 8 Jan 2020 19:50:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727689AbgAHTuC (ORCPT ); Wed, 8 Jan 2020 14:50:02 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:43428 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730398AbgAHTqB (ORCPT ); Wed, 8 Jan 2020 14:46:01 -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 1ipHHC-0006oF-Fz; Wed, 08 Jan 2020 19:45:58 +0000 Received: from ben by deadeye with local (Exim 4.93) (envelope-from ) id 1ipHHB-007dlz-Lg; Wed, 08 Jan 2020 19:45:57 +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 , "Arnd Bergmann" , "Baolin Wang" , "Felipe Balbi" Date: Wed, 08 Jan 2020 19:43:17 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 19/63] usb: gadget: Add the gserial port checking in gs_start_tx() 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 3.16.81-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Baolin Wang commit 511a36d2f357724312bb3776d2f6eed3890928b2 upstream. When usb gadget is set gadget serial function, it will be crash in below situation. It will clean the 'port->port_usb' pointer in gserial_disconnect() function when usb link is inactive, but it will release lock for disabling the endpoints in this function. Druing the lock release period, it maybe complete one request to issue gs_write_complete()--->gs_start_tx() function, but the 'port->port_usb' pointer had been set NULL, thus it will be crash in gs_start_tx() function. This patch adds the 'port->port_usb' pointer checking in gs_start_tx() function to avoid this situation. Signed-off-by: Baolin Wang Signed-off-by: Felipe Balbi Cc: Arnd Bergmann [bwh: Backported to 3.16: adjust filename] Signed-off-by: Ben Hutchings --- drivers/usb/gadget/u_serial.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) --- a/drivers/usb/gadget/u_serial.c +++ b/drivers/usb/gadget/u_serial.c @@ -363,10 +363,15 @@ __acquires(&port->port_lock) */ { struct list_head *pool = &port->write_pool; - struct usb_ep *in = port->port_usb->in; + struct usb_ep *in; int status = 0; bool do_tty_wake = false; + if (!port->port_usb) + return status; + + in = port->port_usb->in; + while (!port->write_busy && !list_empty(pool)) { struct usb_request *req; int len;