Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751314AbaLXBPO (ORCPT ); Tue, 23 Dec 2014 20:15:14 -0500 Received: from eusmtp01.atmel.com ([212.144.249.243]:2121 "EHLO eusmtp01.atmel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751062AbaLXBPN (ORCPT ); Tue, 23 Dec 2014 20:15:13 -0500 Message-ID: <549A138D.50204@atmel.com> Date: Wed, 24 Dec 2014 09:14:53 +0800 From: "Wu, Songjun" Organization: ATMEL User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.3.0 MIME-Version: 1.0 To: CC: , , , , Subject: Re: [PATCH] USB: gadget: udc: atmel: fix possible oops when unloading module References: <1419240374-12179-1-git-send-email-songjun.wu@atmel.com> <20141223162419.GB9147@saruman> In-Reply-To: <20141223162419.GB9147@saruman> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.168.5.13] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 在 12/24/2014 00:24, Felipe Balbi 写道: > On Mon, Dec 22, 2014 at 05:26:14PM +0800, Songjun Wu wrote: >> When unloading the module, the urb request will be dequeued >> and the completion routine will be excuted. >> If no urb packet, the urb request will not be added to the endpoint queue >> and the completion routine pointer in urb request is NULL. >> Accessing to the NULL function pointer will cause the oops issue. >> Add the code to check the urb request is in the endpoint queue or not. >> If the urb request is not in the endpoint queue, a negative error code >> will be returned. > > have you triggered the NULL pointer oops ? Care to add it to the commit > log. Executing the 'insmod g_hid.ko', then executing the 'rmmod g_hid.ko', the NULL pointer oops will be triggered. > > Also, which commit is this fixing ? Does this need to be backported ? > When was the bug introduced ? > >> Signed-off-by: Songjun Wu >> --- >> drivers/usb/gadget/udc/atmel_usba_udc.c | 12 +++++++++++- >> 1 file changed, 11 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/usb/gadget/udc/atmel_usba_udc.c b/drivers/usb/gadget/udc/atmel_usba_udc.c >> index ce88237..48629cc 100644 >> --- a/drivers/usb/gadget/udc/atmel_usba_udc.c >> +++ b/drivers/usb/gadget/udc/atmel_usba_udc.c >> @@ -828,7 +828,7 @@ static int usba_ep_dequeue(struct usb_ep *_ep, struct usb_request *_req) >> { >> struct usba_ep *ep = to_usba_ep(_ep); >> struct usba_udc *udc = ep->udc; >> - struct usba_request *req = to_usba_req(_req); >> + struct usba_request *req; >> unsigned long flags; >> u32 status; >> >> @@ -837,6 +837,16 @@ static int usba_ep_dequeue(struct usb_ep *_ep, struct usb_request *_req) >> >> spin_lock_irqsave(&udc->lock, flags); >> >> + list_for_each_entry(req, &ep->queue, queue) { >> + if (&req->req == _req) >> + break; >> + } >> + >> + if (&req->req != _req) { >> + spin_unlock_irqrestore(&udc->lock, flags); >> + return -EINVAL; >> + } >> + >> if (req->using_dma) { >> /* >> * If this request is currently being transferred, >> -- >> 1.7.9.5 >> > -- 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/