From patchwork Wed Sep 25 10:16:19 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 11160383 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 363B114DB for ; Wed, 25 Sep 2019 10:16:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1DCE921D7C for ; Wed, 25 Sep 2019 10:16:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389138AbfIYKQj (ORCPT ); Wed, 25 Sep 2019 06:16:39 -0400 Received: from mga18.intel.com ([134.134.136.126]:21948 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727141AbfIYKQj (ORCPT ); Wed, 25 Sep 2019 06:16:39 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 25 Sep 2019 03:16:38 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,547,1559545200"; d="scan'208";a="340366339" Received: from dariusvo-mobl.ger.corp.intel.com (HELO localhost) ([10.249.39.150]) by orsmga004.jf.intel.com with ESMTP; 25 Sep 2019 03:16:35 -0700 From: Jarkko Sakkinen To: linux-integrity@vger.kernel.org Cc: Peter Jones , linux-efi@vger.kernel.org, stable@vger.kernel.org, Lyude Paul , Jarkko Sakkinen , Matthew Garrett , Ard Biesheuvel , linux-kernel@vger.kernel.org (open list) Subject: [PATCH v2 2/2] efi+tpm: don't traverse an event log with no events Date: Wed, 25 Sep 2019 13:16:19 +0300 Message-Id: <20190925101622.31457-2-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190925101622.31457-1-jarkko.sakkinen@linux.intel.com> References: <20190925101622.31457-1-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org From: Peter Jones 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. Fixes: c46f3405692d ("tpm: Reserve the TPM final events table") Cc: linux-efi@vger.kernel.org Cc: linux-integrity@vger.kernel.org Cc: stable@vger.kernel.org Signed-off-by: Peter Jones Tested-by: Lyude Paul Reviewed-by: Jarkko Sakkinen Acked-by: Matthew Garrett Acked-by: Ard Biesheuvel Signed-off-by: Jarkko Sakkinen --- drivers/firmware/efi/tpm.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/firmware/efi/tpm.c b/drivers/firmware/efi/tpm.c index 1d3f5ca3eaaf..b9ae5c6f9b9c 100644 --- a/drivers/firmware/efi/tpm.c +++ b/drivers/firmware/efi/tpm.c @@ -75,11 +75,16 @@ 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); + } memblock_reserve((unsigned long)final_tbl, tbl_size + sizeof(*final_tbl)); early_memunmap(final_tbl, sizeof(*final_tbl));