From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BFC90C4363A for ; Thu, 29 Oct 2020 16:02:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4A75120738 for ; Thu, 29 Oct 2020 16:02:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="gil/00/O" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728567AbgJ2QCt (ORCPT ); Thu, 29 Oct 2020 12:02:49 -0400 Received: from z5.mailgun.us ([104.130.96.5]:21796 "EHLO z5.mailgun.us" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728560AbgJ2QCt (ORCPT ); Thu, 29 Oct 2020 12:02:49 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1603987369; h=In-Reply-To: Content-Type: MIME-Version: References: Message-ID: Subject: Cc: To: From: Date: Sender; bh=mwrkVzoPFVrb40b/lFDQN9OPUP730QXZl59lU+BuS4E=; b=gil/00/Odk2laesnc4HHFZWaNWCpLcAuo4kaHJdQO17/vHeyyBtweBByzkeOd2SMtc3ennQq tEKzyYwg48lIHDA6u1pfV4r0d08sXL5YZflkNCOufPzlF3jlmQL8ynrEs5VkWWZXtMOZDSW6 bc18OZJ+ug2MDTDWOA3HxMPIbKs= X-Mailgun-Sending-Ip: 104.130.96.5 X-Mailgun-Sid: WyIxZTE2YSIsICJsaW51eC11c2JAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n06.prod.us-west-2.postgun.com with SMTP id 5f9ae777940cfd47f14663b0 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Thu, 29 Oct 2020 16:01:59 GMT Sender: jackp=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 4822CC43382; Thu, 29 Oct 2020 16:01:59 +0000 (UTC) Received: from jackp-linux.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: jackp) by smtp.codeaurora.org (Postfix) with ESMTPSA id 0BA8AC433C9; Thu, 29 Oct 2020 16:01:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 0BA8AC433C9 Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=fail smtp.mailfrom=jackp@codeaurora.org Date: Thu, 29 Oct 2020 09:01:43 -0700 From: Jack Pham To: Peter Chen Cc: Felipe Balbi , Ruslan Bilovol , Greg Kroah-Hartman , Thinh Nguyen , Andy Shevchenko , "linux-usb@vger.kernel.org" , Ferry Toth Subject: Re: [PATCH v2] usb: gadget: audio: Free requests only after callback Message-ID: <20201029160143.GA31406@jackp-linux.qualcomm.com> References: <20201029062144.3574-1-jackp@codeaurora.org> <20201029082424.GA30677@b29397-desktop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201029082424.GA30677@b29397-desktop> User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Thu, Oct 29, 2020 at 08:24:52AM +0000, Peter Chen wrote: > On 20-10-28 23:21:44, Jack Pham wrote: > > As per the kernel doc for usb_ep_dequeue(), it states that "this > > routine is asynchronous, that is, it may return before the completion > > routine runs". And indeed since v5.0 the dwc3 gadget driver updated > > its behavior to place dequeued requests on to a cancelled list to be > > given back later after the endpoint is stopped. > > > > The free_ep() was incorrectly assuming that a request was ready to > > be freed after calling dequeue which results in a use-after-free > > in dwc3 when it traverses its cancelled list. Fix this by moving > > the usb_ep_free_request() call to the callback itself in case the > > ep is disabled. > > > > Fixes: eb9fecb9e69b0 ("usb: gadget: f_uac2: split out audio core") > > Reported-and-tested-by: Ferry Toth > > Signed-off-by: Jack Pham > > --- > > v2: call free_request() in case of ep_dequeue() failure > > > > drivers/usb/gadget/function/u_audio.c | 12 +++++++++--- > > 1 file changed, 9 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/usb/gadget/function/u_audio.c b/drivers/usb/gadget/function/u_audio.c > > index e6d32c536781..6e69ccf02c95 100644 > > --- a/drivers/usb/gadget/function/u_audio.c > > +++ b/drivers/usb/gadget/function/u_audio.c > > @@ -89,7 +89,12 @@ static void u_audio_iso_complete(struct usb_ep *ep, struct usb_request *req) > > struct snd_uac_chip *uac = prm->uac; > > > > /* i/f shutting down */ > > - if (!prm->ep_enabled || req->status == -ESHUTDOWN) > > + if (!prm->ep_enabled) { > > + usb_ep_free_request(ep, req); > > + return; > > + } > > + > > + if (req->status == -ESHUTDOWN) > > return; > > > > /* > > @@ -336,8 +341,9 @@ static inline void free_ep(struct uac_rtd_params *prm, struct usb_ep *ep) > > > > for (i = 0; i < params->req_number; i++) { > > if (prm->ureq[i].req) { > > - usb_ep_dequeue(ep, prm->ureq[i].req); > > - usb_ep_free_request(ep, prm->ureq[i].req); > > + if (usb_ep_dequeue(ep, prm->ureq[i].req)) > > + usb_ep_free_request(ep, req); > > There is a build error for "req", otherwise: > > Reviewed-and-tested-by: Peter Chen Sorry, careless mistake!! Thanks for testing, V3 on its way. Jack > > + /* else will be freed in u_audio_iso_complete() */ > > prm->ureq[i].req = NULL; > > } > > } > > -- > > 2.24.0 > >