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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 A204DC3A59F for ; Mon, 26 Aug 2019 16:30:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 74FE220874 for ; Mon, 26 Aug 2019 16:30:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732841AbfHZQa3 (ORCPT ); Mon, 26 Aug 2019 12:30:29 -0400 Received: from mga09.intel.com ([134.134.136.24]:55184 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729951AbfHZQa3 (ORCPT ); Mon, 26 Aug 2019 12:30:29 -0400 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 26 Aug 2019 09:30:28 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,433,1559545200"; d="scan'208";a="185008288" Received: from clevorn-mobl.ger.corp.intel.com (HELO localhost) ([10.252.35.202]) by orsmga006.jf.intel.com with ESMTP; 26 Aug 2019 09:30:22 -0700 Date: Mon, 26 Aug 2019 19:30:20 +0300 From: Jarkko Sakkinen To: Peter Jones Cc: Ard Biesheuvel , Roberto Sassu , Matthew Garrett , Bartosz Szczepanek , Lyude Paul , linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] efi+tpm: don't traverse an event log with no events Message-ID: <20190826163020.e7sahr3irqwwneey@linux.intel.com> References: <20190826153028.32639-1-pjones@redhat.com> <20190826153028.32639-2-pjones@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190826153028.32639-2-pjones@redhat.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: NeoMutt/20180716 Sender: linux-efi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org On Mon, Aug 26, 2019 at 11:30:28AM -0400, Peter Jones wrote: > When there are no entries to put into the final event log, some machines > will return the template they would have populated anyway. In this case > the nr_events field is 0, but the rest of the log is just garbage. > > This patch stops us from trying to iterate the table with > __calc_tpm2_event_size() when the number of events in the table is 0. > > Signed-off-by: Peter Jones > Tested-by: Lyude Paul > --- > drivers/firmware/efi/tpm.c | 14 +++++++++----- > 1 file changed, 9 insertions(+), 5 deletions(-) > > diff --git a/drivers/firmware/efi/tpm.c b/drivers/firmware/efi/tpm.c > index 1d3f5ca3eaa..be51ed17c6e 100644 > --- a/drivers/firmware/efi/tpm.c > +++ b/drivers/firmware/efi/tpm.c > @@ -75,11 +75,15 @@ int __init efi_tpm_eventlog_init(void) > goto out; > } > > - tbl_size = tpm2_calc_event_log_size((void *)efi.tpm_final_log > - + sizeof(final_tbl->version) > - + sizeof(final_tbl->nr_events), > - final_tbl->nr_events, > - log_tbl->log); > + tbl_size = 0; > + if (final_tbl->nr_events != 0) { > + void *events = (void *)efi.tpm_final_log > + + sizeof(final_tbl->version) > + + sizeof(final_tbl->nr_events); > + tbl_size = tpm2_calc_event_log_size(events, > + final_tbl->nr_events, > + log_tbl->log); > + } Reviewed-by: Jarkko Sakkinen /Jarkko