From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753030AbbK3F35 (ORCPT ); Mon, 30 Nov 2015 00:29:57 -0500 Received: from mga14.intel.com ([192.55.52.115]:25658 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752788AbbK3F31 (ORCPT ); Mon, 30 Nov 2015 00:29:27 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,363,1444719600"; d="scan'208";a="696420404" From: changbin.du@intel.com To: johnyoun@synopsys.com Cc: gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, "Du, Changbin" Subject: [PATCH 2/2] usb: dwc2: forbid queuing request to a disabled ep Date: Mon, 30 Nov 2015 13:21:28 +0800 Message-Id: <1448860888-9841-3-git-send-email-changbin.du@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1448860888-9841-1-git-send-email-changbin.du@intel.com> References: <1448860888-9841-1-git-send-email-changbin.du@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 dwc2 process the request queued on step 2, will cause kernel NULL pointer dereference exception. Signed-off-by: Du, Changbin --- drivers/usb/dwc2/gadget.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c index 586bbcd..4d637ab 100644 --- a/drivers/usb/dwc2/gadget.c +++ b/drivers/usb/dwc2/gadget.c @@ -786,6 +786,12 @@ static int dwc2_hsotg_ep_queue(struct usb_ep *ep, struct usb_request *req, ep->name, req, req->length, req->buf, req->no_interrupt, req->zero, req->short_not_ok); + if (!hs_ep->enabled) { + dev_warn(hs->dev, "%s: cannot queue to disabled ep\n", + __func__); + return -ESHUTDOWN; + } + /* Prevent new request submission when controller is suspended */ if (hs->lx_state == DWC2_L2) { dev_dbg(hs->dev, "%s: don't submit request while suspended\n", -- 2.5.0