From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755306AbbLDH3Q (ORCPT ); Fri, 4 Dec 2015 02:29:16 -0500 Received: from mga14.intel.com ([192.55.52.115]:47467 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754997AbbLDH3O (ORCPT ); Fri, 4 Dec 2015 02:29:14 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,380,1444719600"; d="scan'208";a="612384487" From: changbin.du@intel.com To: balbi@ti.com Cc: gregkh@linuxfoundation.org, John.Youn@synopsys.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, "Du, Changbin" Subject: [PATCH] usb: gadget: forbid queuing request to a disabled ep Date: Fri, 4 Dec 2015 15:21:16 +0800 Message-Id: <1449213676-27334-1-git-send-email-changbin.du@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <0C18FE92A7765D4EB9EE5D38D86A563A01DE83B2@SHSMSX103.ccr.corp.intel.com> References: <0C18FE92A7765D4EB9EE5D38D86A563A01DE83B2@SHSMSX103.ccr.corp.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Du, Changbin" Queue a request to disabled ep doesn't make sense, and induce caller make mistakes. Here is a example for the android mtp gadget function driver. A mem corruption can happen on below senario. 1) On disconnect, mtp driver disable its EPs, 2) During send_file_work and receive_file_work, mtp queues a request to ep. (The mtp driver need improve its synchronization logic!) 3) mtp_function_unbind is invoked and all mtp requests are freed. 4) when udc process the request queued on step 2, will cause kernel NULL pointer dereference exception. Signed-off-by: Du, Changbin --- This patch is seprated from below patches because gadget layer has added the 'enabled' flag in v4.4. so abandon it and submit new one. [PATCH 0/2] Two fix for dwc2 gadget driver usb: dwc2: add ep enabled flag to avoid double enable/disable usb: dwc2: forbid queuing request to a disabled ep --- include/linux/usb/gadget.h | 3 +++ 1 file changed, 3 insertions(+) diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h index 3d583a1..d813bd2 100644 --- a/include/linux/usb/gadget.h +++ b/include/linux/usb/gadget.h @@ -402,6 +402,9 @@ static inline void usb_ep_free_request(struct usb_ep *ep, static inline int usb_ep_queue(struct usb_ep *ep, struct usb_request *req, gfp_t gfp_flags) { + if (!ep->enabled) + return -ESHUTDOWN; + return ep->ops->queue(ep, req, gfp_flags); } -- 2.5.0