From patchwork Thu Feb 8 20:32:06 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Bottomley X-Patchwork-Id: 10207979 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 3BFF1602D8 for ; Thu, 8 Feb 2018 20:32:09 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 24BEB2966D for ; Thu, 8 Feb 2018 20:32:09 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1752A29674; Thu, 8 Feb 2018 20:32:09 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6768D2966D for ; Thu, 8 Feb 2018 20:32:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752176AbeBHUcI (ORCPT ); Thu, 8 Feb 2018 15:32:08 -0500 Received: from bedivere.hansenpartnership.com ([66.63.167.143]:59612 "EHLO bedivere.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752179AbeBHUcH (ORCPT ); Thu, 8 Feb 2018 15:32:07 -0500 Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 4F47D8EE171; Thu, 8 Feb 2018 12:32:07 -0800 (PST) Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id lqXF2ElypIEm; Thu, 8 Feb 2018 12:32:07 -0800 (PST) Received: from [153.66.254.194] (unknown [50.35.65.221]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by bedivere.hansenpartnership.com (Postfix) with ESMTPSA id E2B488EE0A4; Thu, 8 Feb 2018 12:32:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=hansenpartnership.com; s=20151216; t=1518121927; bh=Au19IYoRv8YIOJ2ldKES75jd4lH3lDjQr5N8AgCW6LM=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=ucttvP0hk+IdQQoE3HhyFODlaTyMqU+SDEYewkyZgoUfxMMpFS2o/XfQinaUv0u8k IUKry/NGycpegP/fR4Ka2EbZh2+mdbNXt5t0UkMYCYZ8SmbTaXb/XhQ2XR+wgoC1rE YEdoOm4ry7HIOMG6CoxaAiKITTeGjv/Mln7dyUyg= Message-ID: <1518121926.21828.17.camel@HansenPartnership.com> Subject: [PATCH v2 5/5] tpm_tis: fix potential buffer overruns caused by bit glitches on the bus From: James Bottomley To: linux-integrity@vger.kernel.org Cc: Jeremy Boone , Jarkko Sakkinen Date: Thu, 08 Feb 2018 12:32:06 -0800 In-Reply-To: <1518121576.21828.10.camel@HansenPartnership.com> References: <1518121576.21828.10.camel@HansenPartnership.com> X-Mailer: Evolution 3.20.5 Mime-Version: 1.0 Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Jeremy Boone Discrete TPMs are often connected over slow serial buses which, on some platforms, can have glitches causing bit flips. In all the driver _recv() functions, we need to use a u32 to unmarshal the response size, otherwise a bit flip of the 31st bit would cause the expected variable to go negative, which would then try to read a huge amount of data. Also sanity check that the expected amount of data is large enough for the TPM header. Signed-off-by: Jeremy Boone Cc: stable@vger.kernel.org Signed-off-by: James Bottomley --- drivers/char/tpm/tpm_tis_core.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c index fdde971bc810..7561922bc8f8 100644 --- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -202,7 +202,8 @@ static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count) { struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev); int size = 0; - int expected, status; + int status; + u32 expected; if (count < TPM_HEADER_SIZE) { size = -EIO; @@ -217,7 +218,7 @@ static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count) } expected = be32_to_cpu(*(__be32 *) (buf + 2)); - if (expected > count) { + if (expected > count || expected < TPM_HEADER_SIZE) { size = -EIO; goto out; }