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=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 1B4E5C10F13 for ; Tue, 16 Apr 2019 07:25:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DD992206BA for ; Tue, 16 Apr 2019 07:25:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727828AbfDPHZf (ORCPT ); Tue, 16 Apr 2019 03:25:35 -0400 Received: from mga01.intel.com ([192.55.52.88]:35405 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727783AbfDPHZf (ORCPT ); Tue, 16 Apr 2019 03:25:35 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 16 Apr 2019 00:25:34 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,355,1549958400"; d="scan'208";a="141052766" Received: from jsakkine-mobl1.tm.intel.com (HELO localhost) ([10.237.50.189]) by fmsmga008.fm.intel.com with ESMTP; 16 Apr 2019 00:25:32 -0700 Date: Tue, 16 Apr 2019 10:25:31 +0300 From: Jarkko Sakkinen To: Greg KH Cc: stable@vger.kernel.org, James Morris , Tomas Winkler , Jerry Snitselaar Subject: Re: [PATCH] tpm/tpm_crb: Avoid unaligned reads in crb_recv() Message-ID: <20190416072531.GA12275@linux.intel.com> References: <20190410135432.28684-1-jarkko.sakkinen@linux.intel.com> <20190415104824.GB9397@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190415104824.GB9397@kroah.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.10.1 (2018-07-13) Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Mon, Apr 15, 2019 at 12:48:25PM +0200, Greg KH wrote: > On Wed, Apr 10, 2019 at 04:54:32PM +0300, Jarkko Sakkinen wrote: > > commit 3d7a850fdc1a2e4d2adbc95cc0fc962974725e88 upstream > > > > The current approach to read first 6 bytes from the response and then tail > > of the response, can cause the 2nd memcpy_fromio() to do an unaligned read > > (e.g. read 32-bit word from address aligned to a 16-bits), depending on how > > memcpy_fromio() is implemented. If this happens, the read will fail and the > > memory controller will fill the read with 1's. > > > > This was triggered by 170d13ca3a2f, which should be probably refined to > > check and react to the address alignment. Before that commit, on x86 > > memcpy_fromio() turned out to be memcpy(). By a luck GCC has done the right > > thing (from tpm_crb's perspective) for us so far, but we should not rely on > > that. Thus, it makes sense to fix this also in tpm_crb, not least because > > the fix can be then backported to stable kernels and make them more robust > > when compiled in differing environments. > > > > Cc: stable@vger.kernel.org > > Cc: James Morris > > Cc: Tomas Winkler > > Cc: Jerry Snitselaar > > Fixes: 30fc8d138e91 ("tpm: TPM 2.0 CRB Interface") > > Signed-off-by: Jarkko Sakkinen > > Reviewed-by: Jerry Snitselaar > > Acked-by: Tomas Winkler > > --- > > backport v4.4.178 > > drivers/char/tpm/tpm_crb.c | 22 ++++++++++++++++------ > > 1 file changed, 16 insertions(+), 6 deletions(-) > > I need a 4.9.y version first before I can take a 4.4.y version, as we do > not want anyone to have a regression moving from 4.4.y to a newer > kernel. OK, will do. /Jarkko