From patchwork Tue Jul 4 13:54:18 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Steffen X-Patchwork-Id: 9825187 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 43C79602F0 for ; Tue, 4 Jul 2017 14:29:38 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 31EDC26E74 for ; Tue, 4 Jul 2017 14:29:38 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 25EC926E16; Tue, 4 Jul 2017 14:29:38 +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 lists.sourceforge.net (lists.sourceforge.net [216.34.181.88]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id A449426E16 for ; Tue, 4 Jul 2017 14:29:37 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=sfs-ml-1.v29.ch3.sourceforge.com) by sfs-ml-1.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1dSOpc-0002jJ-Ns; Tue, 04 Jul 2017 14:29:36 +0000 Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-1.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1dSOpb-0002j3-BG for tpmdd-devel@lists.sourceforge.net; Tue, 04 Jul 2017 14:29:35 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sourceforge.net; s=x; h=Content-Type:MIME-Version:Message-ID:Date:Subject:CC:To:From; bh=5Wp85UmCEC6n4uqwTAlt0XLCaePIPFGYyZaF68R2L2w=; b=QD5ZJrHR5dGcLIEt0KWhqHgCxlqtiSrrn3S8cpjVkukdGXxstCSGAv67QnqlqRA+Wl6I7CxIuiONleRgAvw5XBd07E1vX9jgEaNMe0bnvTs6g7F9QTa0geWx6n5U9PluKJg3Cb/11pjSjR9LZ1tfQ9rj9TI3EHwP3oVCR+Z9Gwk=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sf.net; s=x; h=Content-Type:MIME-Version:Message-ID:Date:Subject:CC:To:From; bh=5Wp85UmCEC6n4uqwTAlt0XLCaePIPFGYyZaF68R2L2w=; b=SqrlQrbhLOMb4lXjzERiJqiYG3igpdwMpDkDZFkQ9mRM3AkDeudAwbIuKYazVIs4ywcXOeWwE/ZaVptTvM/S73i2amtD0CYMnz7XYNC+S45IijwKoDgEHF8iZRpH+tK8OCgvgdy+pdjFUuZaLkOUE2vGzMzLmOG6laJn/ciyBeE=; Received-SPF: pass (sog-mx-1.v43.ch3.sourceforge.com: domain of infineon.com designates 217.10.52.18 as permitted sender) client-ip=217.10.52.18; envelope-from=alexander.steffen@infineon.com; helo=smtp2.infineon.com; Received: from smtp2.infineon.com ([217.10.52.18]) by sog-mx-1.v43.ch3.sourceforge.com with esmtps (TLSv1:AES256-SHA:256) (Exim 4.76) id 1dSOpa-0005r2-5O for tpmdd-devel@lists.sourceforge.net; Tue, 04 Jul 2017 14:29:35 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=infineon.com; i=@infineon.com; q=dns/txt; s=IFXMAIL; t=1499178574; x=1530714574; h=from:to:cc:subject:date:message-id:mime-version; bh=uB2+fHSyhrmLI+NBk46DLpfZBfzmGK0c7XCJcfEKeLg=; b=DtYEB7UbeRWZzbkbZnu3QPBrGRWFkeaV16OxGXBwz+xsA0fR8Csm7Vmz eeyFSSdJ4SYwOLAjz7PX1imvRk/GrdnYRIMsOejDC8DokmQFP53qbkvlc X+oZE5xlWJPg4Hb8wxOquGxRaD4eCHNAN5drKn9i8XMtwqpbuW4Rfa5jk c=; X-SBRS: None Received: from unknown (HELO mucxv003.muc.infineon.com) ([172.23.11.20]) by smtp2.infineon.com with ESMTP/TLS/AES256-GCM-SHA384; 04 Jul 2017 15:54:47 +0200 Received: from MUCSE608.infineon.com (unknown [172.23.7.109]) by mucxv003.muc.infineon.com (Postfix) with ESMTPS; Tue, 4 Jul 2017 15:54:46 +0200 (CEST) Received: from MUCSE603.infineon.com (172.23.7.104) by MUCSE608.infineon.com (172.23.7.109) with Microsoft SMTP Server (TLS) id 15.0.1263.5; Tue, 4 Jul 2017 15:54:47 +0200 Received: from ABGN5CG4522MQD.eu.infineon.com (172.29.170.97) by MUCSE603.infineon.com (172.23.7.104) with Microsoft SMTP Server (TLS) id 15.0.1263.5; Tue, 4 Jul 2017 15:54:46 +0200 From: Alexander Steffen To: Date: Tue, 4 Jul 2017 15:54:18 +0200 Message-ID: <20170704135419.1692-1-Alexander.Steffen@infineon.com> X-Mailer: git-send-email 2.11.1.windows.1 MIME-Version: 1.0 X-Originating-IP: [172.29.170.97] X-ClientProxiedBy: MUCSE601.infineon.com (172.23.7.102) To MUCSE603.infineon.com (172.23.7.104) X-Headers-End: 1dSOpa-0005r2-5O Subject: [tpmdd-devel] [PATCH 1/2] tpm-dev-common: Reject too short writes X-BeenThere: tpmdd-devel@lists.sourceforge.net X-Mailman-Version: 2.1.21 Precedence: list List-Id: Tpm Device Driver maintainance List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: stable@vger.kernel.org Errors-To: tpmdd-devel-bounces@lists.sourceforge.net X-Virus-Scanned: ClamAV using ClamSMTP tpm_common_write() in tpm-dev-common.c discards the information how much data has actually been written to the buffer. Instead, all other code has to rely on the commandSize field in the TPM command header to figure out how many valid bytes are supposed to be in the buffer. But there is nothing that enforces the value in the header to match the actual buffer contents. So by claiming a larger size in the header than has been written, stale buffer contents are sent to the TPM. With this commit, this problem is detected and rejected accordingly. This should have been fixed with CVE-2011-1161 long ago, but apparently a correct version of that patch never made it into the kernel. Cc: stable@vger.kernel.org Signed-off-by: Alexander Steffen --- drivers/char/tpm/tpm-dev-common.c | 2 +- drivers/char/tpm/tpm-interface.c | 9 ++++++--- drivers/char/tpm/tpm.h | 3 ++- 3 files changed, 9 insertions(+), 5 deletions(-) diff --git a/drivers/char/tpm/tpm-dev-common.c b/drivers/char/tpm/tpm-dev-common.c index 610638a..c39b581 100644 --- a/drivers/char/tpm/tpm-dev-common.c +++ b/drivers/char/tpm/tpm-dev-common.c @@ -119,7 +119,7 @@ ssize_t tpm_common_write(struct file *file, const char __user *buf, return -EPIPE; } out_size = tpm_transmit(priv->chip, space, priv->data_buffer, - sizeof(priv->data_buffer), 0); + sizeof(priv->data_buffer), in_size, 0); tpm_put_ops(priv->chip); if (out_size < 0) { diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index 3123a6e..a452cd0 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -375,6 +375,7 @@ static bool tpm_validate_command(struct tpm_chip *chip, * @chip: TPM chip to use * @buf: TPM command buffer * @bufsiz: length of the TPM command buffer + * @bufvalid: number of valid bytes in the TPM command buffer * @flags: tpm transmit flags - bitmap * * Return: @@ -382,7 +383,8 @@ static bool tpm_validate_command(struct tpm_chip *chip, * A negative number for system errors (errno). */ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space, - u8 *buf, size_t bufsiz, unsigned int flags) + u8 *buf, size_t bufsiz, size_t bufvalid, + unsigned int flags) { struct tpm_output_header *header = (void *)buf; int rc; @@ -401,7 +403,7 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space, ordinal = be32_to_cpu(*((__be32 *) (buf + 6))); if (count == 0) return -ENODATA; - if (count > bufsiz) { + if (count > bufsiz || count > bufvalid) { dev_err(&chip->dev, "invalid count value %x %zx\n", count, bufsiz); return -E2BIG; @@ -522,7 +524,8 @@ ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_space *space, int err; ssize_t len; - len = tpm_transmit(chip, space, (u8 *)buf, bufsiz, flags); + len = tpm_transmit(chip, space, (u8 *)buf, bufsiz, + be32_to_cpu(header->length), flags); if (len < 0) return len; diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index 71d661a..116f2b8 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -509,7 +509,8 @@ enum tpm_transmit_flags { }; ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space, - u8 *buf, size_t bufsiz, unsigned int flags); + u8 *buf, size_t bufsiz, size_t bufvalid, + unsigned int flags); ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_space *space, const void *buf, size_t bufsiz, size_t min_rsp_body_length, unsigned int flags,