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=-5.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 88C5FC4360F for ; Thu, 28 Mar 2019 12:34:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5876C21773 for ; Thu, 28 Mar 2019 12:34:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726491AbfC1Meb (ORCPT ); Thu, 28 Mar 2019 08:34:31 -0400 Received: from mga07.intel.com ([134.134.136.100]:32596 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726029AbfC1Meb (ORCPT ); Thu, 28 Mar 2019 08:34:31 -0400 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 28 Mar 2019 05:34:30 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,280,1549958400"; d="scan'208";a="126618646" Received: from jsakkine-mobl1.tm.intel.com (HELO localhost) ([10.237.50.182]) by orsmga007.jf.intel.com with ESMTP; 28 Mar 2019 05:34:28 -0700 Date: Thu, 28 Mar 2019 14:34:28 +0200 From: Jarkko Sakkinen To: Tadeusz Struk Cc: grawity@gmail.com, James.Bottomley@HansenPartnership.com, linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH v4] tpm: fix an invalid condition in tpm_common_poll Message-ID: <20190328123428.GF7094@linux.intel.com> References: <155371155820.17863.10580533125620125669.stgit@tstruk-mobl1.jf.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <155371155820.17863.10580533125620125669.stgit@tstruk-mobl1.jf.intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Mar 27, 2019 at 11:32:38AM -0700, Tadeusz Struk wrote: > The poll condition should only check response_length, > because reads should only be issued if there is data to read. > The response_read flag only prevents double writes. > The problem was that the write set the response_read to false, > enqued a tpm job, and returned. Then application called poll > which checked the response_read flag and returned EPOLLIN. > Then the application called read, but got nothing. > After all that the async_work kicked in. > Added also mutex_lock around the poll check to prevent > other possible race conditions. > > Cc: stable@vger.kernel.org > Fixes: 9488585b21bef0df12 ("tpm: add support for partial reads") > Reported-by: Mantas Mikulėnas > Tested-by: Mantas Mikulėnas > Signed-off-by: Tadeusz Struk Reviewed-by: Jarkko Sakkinen Thank you, it is applied. /Jarkko