Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755914AbbLQKIk (ORCPT ); Thu, 17 Dec 2015 05:08:40 -0500 Received: from mga11.intel.com ([192.55.52.93]:32403 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755302AbbLQKIi (ORCPT ); Thu, 17 Dec 2015 05:08:38 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,440,1444719600"; d="scan'208";a="843122483" 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, lkp@01.org, fengguang.wu@intel.com, "Du, Changbin" Subject: [PATCH v3] usb: gadget: forbid queuing request to a disabled ep Date: Thu, 17 Dec 2015 18:00:31 +0800 Message-Id: <1450346431-8064-1-git-send-email-changbin.du@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <87h9jifi9x.fsf@saruman.tx.rr.com> References: <87h9jifi9x.fsf@saruman.tx.rr.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1566 Lines: 44 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 --- change from v2: igonre ep0 as it always enabled during usb session. change from v1: add WARN_ON_ONCE message. --- 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..0c5d9ea 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 (WARN_ON_ONCE(!ep->enabled && !ep->address)) + return -ESHUTDOWN; + return ep->ops->queue(ep, req, gfp_flags); } -- 2.5.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/