From patchwork Sat May 22 00:44:21 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wesley Cheng X-Patchwork-Id: 12274255 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=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 F2E0BC4707E for ; Sat, 22 May 2021 00:44:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CD95B613DB for ; Sat, 22 May 2021 00:44:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230401AbhEVAqF (ORCPT ); Fri, 21 May 2021 20:46:05 -0400 Received: from so254-9.mailgun.net ([198.61.254.9]:27332 "EHLO so254-9.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230280AbhEVAp7 (ORCPT ); Fri, 21 May 2021 20:45:59 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1621644274; h=Message-Id: Date: Subject: Cc: To: From: Sender; bh=v70XeN85MmH6JrlfKKi2igLz2OW8mPpsFWoQ9lHM85k=; b=r8yRJcJhjMxz0kzLpaOa3bcHjgC9r4ngZYAz3DgX0Q/Dcg3Obja7B8qzhr++JQC9VsFhnQ97 5NZkj2IOzvcwWKDG1+v+R9zZzeysXY2L80k+TNQ3WefbZnDzHIwJIOJ2la6a/YCDAwHl9i9b rwJJyAmI3h9iArGTs5QADizc1go= X-Mailgun-Sending-Ip: 198.61.254.9 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-n07.prod.us-east-1.postgun.com with SMTP id 60a853eab15734c8f966ad1f (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Sat, 22 May 2021 00:44:26 GMT Sender: wcheng=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 3F757C433D3; Sat, 22 May 2021 00:44:26 +0000 (UTC) Received: from wcheng-linux.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: wcheng) by smtp.codeaurora.org (Postfix) with ESMTPSA id 2F96BC433D3; Sat, 22 May 2021 00:44:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 2F96BC433D3 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=wcheng@codeaurora.org From: Wesley Cheng To: balbi@kernel.org, gregkh@linuxfoundation.org Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, jackp@codeaurora.org, Wesley Cheng Subject: [PATCH] usb: gadget: f_fs: Ensure io_completion_wq is idle during unbind Date: Fri, 21 May 2021 17:44:21 -0700 Message-Id: <1621644261-1236-1-git-send-email-wcheng@codeaurora.org> X-Mailer: git-send-email 2.7.4 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org During unbind, ffs_func_eps_disable() will be executed, resulting in completion callbacks for any pending USB requests. When using AIO, irrespective of the completion status, io_data work is queued to io_completion_wq to evaluate and handle the completed requests. Since work runs asynchronously to the unbind() routine, there can be a scenario where the work runs after the USB gadget has been fully removed, resulting in accessing of a resource which has been already freed. (i.e. usb_ep_free_request() accessing the USB ep structure) Explicitly drain the io_completion_wq, instead of relying on the destroy_workqueue() (in ffs_data_put()) to make sure no pending completion work items are running. Signed-off-by: Wesley Cheng --- drivers/usb/gadget/function/f_fs.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c index bf10919..d4844af 100644 --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -3567,6 +3567,9 @@ static void ffs_func_unbind(struct usb_configuration *c, ffs->func = NULL; } + /* Drain any pending AIO completions */ + drain_workqueue(ffs->io_completion_wq); + if (!--opts->refcnt) functionfs_unbind(ffs);