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=-2.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS,T_DKIMWL_WL_HIGH,USER_AGENT_MUTT 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 A99F3C43219 for ; Mon, 29 Apr 2019 09:30:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 708202075E for ; Mon, 29 Apr 2019 09:30:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556530249; bh=owoB77c7NATgk+ooMeLl7iThCAiiTo0e/zgPyrGR8es=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=Hwp572smKQmkluyTmKmIwS9CN69hKraWRe6TeESpTeBNFUeEeSEB7MlKualc+FNuF P1ckHDjJ7Sl7tEf7KSpaTSmVoPcIodquAyJwS9Qi2Fv2TztfvmMie/dFuVWX9lPvr2 jaOkdUz0LSLDd1oEhXAXB62Fi4WaEH+ugmJ9QEOA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727639AbfD2Jat (ORCPT ); Mon, 29 Apr 2019 05:30:49 -0400 Received: from mail-lf1-f67.google.com ([209.85.167.67]:45497 "EHLO mail-lf1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727259AbfD2Jas (ORCPT ); Mon, 29 Apr 2019 05:30:48 -0400 Received: by mail-lf1-f67.google.com with SMTP id t11so7286144lfl.12 for ; Mon, 29 Apr 2019 02:30:47 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=U2nlqxL152YLC8xQ5ty7B2o8ABIvpmarGKYSJrerfTo=; b=sAxKMLc+lx3FYUAmSsiS1fBd5Xs1/bHqFbq0F2uIlhsPsl5FxcK2QBpB2wWsc+pX5S oMZC0XbiQq1FFedcBU5D6kTigkStFG4cHCd+AU9y3MJxsRlyw7frhMGxMctEjHKJe2BB hVvmBBTHy1RtOYb3k+RE4zqLTvhk9hb6QNvRwPE/qfc80G/BjAmwxnBQiS0BURUvNfab 5aepfGkGH7IJCcPzhTKX1VYSprChg2duXZ2NWBj1mGRvhj2O6ad2QrBrfWyPju5hLy0L bHieE0qWX/468OZVJV1B22K1IB/giL0Fkq5nzk84zCdv3FnK0euQ9Z1ima0v1K0RXcmP AgeA== X-Gm-Message-State: APjAAAXR3szlylWTKcy16ZqMOtv0fwGq6rKa9Fgvd5SYNPXZnaeWV6nZ iPkj/7lyamFAAhCMnA1gksM= X-Google-Smtp-Source: APXvYqwezKoTo4PC9+FCnNOn+sdBge4JnquQhZ5US/qYRjHE1FejPm1/cxsoZXKkTNOofYIIlnCzdA== X-Received: by 2002:ac2:538a:: with SMTP id g10mr23278229lfh.141.1556530247064; Mon, 29 Apr 2019 02:30:47 -0700 (PDT) Received: from xi.terra (c-74bee655.07-184-6d6c6d4.bbcust.telenor.se. [85.230.190.116]) by smtp.gmail.com with ESMTPSA id q78sm643054lje.93.2019.04.29.02.30.45 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 29 Apr 2019 02:30:46 -0700 (PDT) Received: from johan by xi.terra with local (Exim 4.91) (envelope-from ) id 1hL2cZ-000326-AT; Mon, 29 Apr 2019 11:30:47 +0200 Date: Mon, 29 Apr 2019 11:30:47 +0200 From: Johan Hovold To: Alan Stern , Oliver Neukum , Greg Kroah-Hartman Cc: linux-usb@vger.kernel.org, Johan Hovold Subject: Re: [PATCH 0/5] USB: fix tty unthrottle races Message-ID: <20190429093047.GH26546@localhost> References: <20190425160540.10036-1-johan@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190425160540.10036-1-johan@kernel.org> User-Agent: Mutt/1.11.4 (2019-03-13) Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Thu, Apr 25, 2019 at 06:05:35PM +0200, Johan Hovold wrote: > This series fixes a couple of long-standing issues in USB serial and > cdc-acm which essentially share the same implementation. > > As noted by Oliver a few years back, read-urb completion can race with > unthrottle() running on another CPU and this can potentially lead to > memory corruption. This particular bug in cdc-acm was unfortunately > reintroduced a year later. > > There's also a second race due to missing memory barriers which could > theoretically lead to the port staying throttled until reopened on > weakly ordered systems. A second set of memory barriers should address > that. > Note that the cdc-acm patches have so far only been compile tested. I've tested also the cdc-acm changes now. So unless anyone complains, I'll apply the USB-serial ones in a few days, and maybe Greg can pick up the cdc-acm patches. Johan