From mboxrd@z Thu Jan 1 00:00:00 1970 From: Manu Gautam Subject: Re: [PATCH] usb: dwc3: gadget: Fail request submission if it was already queued Date: Fri, 11 Jan 2019 13:54:46 +0530 Message-ID: References: <20190111060212.7390-1-mgautam@codeaurora.org> <87pnt3od02.fsf@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <87pnt3od02.fsf@linux.intel.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Felipe Balbi Cc: linux-arm-msm@vger.kernel.org, Greg Kroah-Hartman , "open list:DESIGNWARE USB3 DRD IP DRIVER" , open list List-Id: linux-arm-msm@vger.kernel.org Hi, On 1/11/2019 1:13 PM, Felipe Balbi wrote: > Hi, > > Manu Gautam writes: >> If a function driver tries to re-submit an already queued request, >> it can results in corruption of pending/started request lists. >> Catch such conditions and fail the request submission to DCD. >> >> Signed-off-by: Manu Gautam >> --- >> drivers/usb/dwc3/gadget.c | 6 ++++++ >> 1 file changed, 6 insertions(+) >> >> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c >> index 679c12e14522..51716c6b286a 100644 >> --- a/drivers/usb/dwc3/gadget.c >> +++ b/drivers/usb/dwc3/gadget.c >> @@ -1290,6 +1290,12 @@ static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req) >> &req->request, req->dep->name)) >> return -EINVAL; >> >> + if (req->request.status == -EINPROGRESS) { > this test is really not enough. What if gadget driver set status to > EINPROGRESS before submission? A better check would involve making sure > req isn't part of dep->pending_list or dep->started_list or > dep->cancelled_list. It's clear that this won't work very well as the > amount of requests grow. Thanks for quick review. 'request.status' check can be replaced: +if (!list_empty(&req->list) { And replace list_del with list_del_init from dwc3_gadget_giveback() > > Anyway, which gadget driver did this? Why is it only affecting dwc3? Function driver is not in upstream (f_mtp.c). > -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project