From patchwork Wed Jan 19 23:38:03 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Gustavo A. R. Silva" X-Patchwork-Id: 12717887 X-Patchwork-Delegate: gustavo@embeddedor.com Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E0CB0C433EF for ; Wed, 19 Jan 2022 23:31:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344381AbiASXbd (ORCPT ); Wed, 19 Jan 2022 18:31:33 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55962 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229583AbiASXbc (ORCPT ); Wed, 19 Jan 2022 18:31:32 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B7D31C061574; Wed, 19 Jan 2022 15:31:31 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 5FFB3B81C34; Wed, 19 Jan 2022 23:31:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B425AC004E1; Wed, 19 Jan 2022 23:31:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1642635089; bh=wpaaWCiYZyAnyuuz1kY2kggtn4GBEDvuWq+07dNMQFk=; h=Date:From:To:Cc:Subject:From; b=io84APfNHqLHI5kNhwUZT5KvdPqWANNRAbPOvSh61dNTzPetytlYU00E1zQE/cWTD GUdBTOkcTVNXtdT1qWKdd59Yb8+PGAWbq1FG/ehBWJPAydk4k784MxWwMFyS8OCiSf qR75YfkvTTJ8jBSOtYClNRIrQt3Et4UF2MKkpzSbN/hY8XcJWwLu98o2F33BE9y8zT 5aDGPKY/g4U+jhWacZ8wAU7xQrisL3IZ6gdDgKn3JkYhuXlz18EZrobRPdbSk8JMJ8 qUuWPsPP0wQClq67t1lxzH0pt/b+aIqUks8NBm6ERdf8TQhs6mSe/WHbfBkwe9LHTM bf3fSvEio+49w== Date: Wed, 19 Jan 2022 17:38:03 -0600 From: "Gustavo A. R. Silva" To: Peter Huewe , Jarkko Sakkinen , Jason Gunthorpe Cc: linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" , linux-hardening@vger.kernel.org Subject: [PATCH][next] tpm: xen-tpmfront: Use struct_size() helper Message-ID: <20220119233803.GA66829@embeddedor> MIME-Version: 1.0 Content-Disposition: inline Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org Make use of the struct_size() helper instead of an open-coded version, in order to avoid any potential type mistakes or integer overflows that, in the worse scenario, could lead to heap overflows. Also, address the following sparse warning: drivers/char/tpm/xen-tpmfront.c:131:16: warning: using sizeof on a flexible structure Link: https://github.com/KSPP/linux/issues/160 Link: https://github.com/KSPP/linux/issues/174 Signed-off-by: Gustavo A. R. Silva Reviewed-by: Jarkko Sakkinen --- drivers/char/tpm/xen-tpmfront.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/char/tpm/xen-tpmfront.c b/drivers/char/tpm/xen-tpmfront.c index da5b30771418..f53e0cf1ec7e 100644 --- a/drivers/char/tpm/xen-tpmfront.c +++ b/drivers/char/tpm/xen-tpmfront.c @@ -126,16 +126,16 @@ static void vtpm_cancel(struct tpm_chip *chip) notify_remote_via_evtchn(priv->evtchn); } -static unsigned int shr_data_offset(struct vtpm_shared_page *shr) +static size_t shr_data_offset(struct vtpm_shared_page *shr) { - return sizeof(*shr) + sizeof(u32) * shr->nr_extra_pages; + return struct_size(shr, extra_pages, shr->nr_extra_pages); } static int vtpm_send(struct tpm_chip *chip, u8 *buf, size_t count) { struct tpm_private *priv = dev_get_drvdata(&chip->dev); struct vtpm_shared_page *shr = priv->shr; - unsigned int offset = shr_data_offset(shr); + size_t offset = shr_data_offset(shr); u32 ordinal; unsigned long duration; @@ -177,7 +177,7 @@ static int vtpm_recv(struct tpm_chip *chip, u8 *buf, size_t count) { struct tpm_private *priv = dev_get_drvdata(&chip->dev); struct vtpm_shared_page *shr = priv->shr; - unsigned int offset = shr_data_offset(shr); + size_t offset = shr_data_offset(shr); size_t length = shr->length; if (shr->state == VTPM_STATE_IDLE)