Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751951AbdCCPT7 (ORCPT ); Fri, 3 Mar 2017 10:19:59 -0500 Received: from mga11.intel.com ([192.55.52.93]:32420 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751583AbdCCPTw (ORCPT ); Fri, 3 Mar 2017 10:19:52 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.35,237,1484035200"; d="scan'208";a="71844053" From: Jarkko Sakkinen To: tpmdd-devel@lists.sourceforge.net Cc: linux-security-module@vger.kernel.org, James.Bottomley@HansenPartnership.com, dhowells@redhat.com, Jarkko Sakkinen , Peter Huewe , Marcel Selhorst , Jason Gunthorpe , linux-kernel@vger.kernel.org (open list) Subject: [PATCH v3 1/7] tpm: move length validation to tpm_transmit() Date: Fri, 3 Mar 2017 17:19:02 +0200 Message-Id: <20170303151912.14752-2-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.9.3 In-Reply-To: <20170303151912.14752-1-jarkko.sakkinen@linux.intel.com> References: <20170303151912.14752-1-jarkko.sakkinen@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1987 Lines: 65 Check that the length matches the length reported by the response header already in tpm_transmit() to improve validation. Signed-off-by: Jarkko Sakkinen Tested-by: James Bottomley Reviewed-by: James Bottomley --- drivers/char/tpm/tpm-interface.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index bd2128e..708d356 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -343,6 +343,7 @@ EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration); ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz, unsigned int flags) { + const struct tpm_output_header *header = (void *)buf; ssize_t rc; u32 count, ordinal; unsigned long stop; @@ -406,9 +407,18 @@ ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz, out_recv: rc = chip->ops->recv(chip, (u8 *) buf, bufsiz); - if (rc < 0) + if (rc < 0) { dev_err(&chip->dev, "tpm_transmit: tpm_recv: error %zd\n", rc); + goto out; + } else if (rc < TPM_HEADER_SIZE) { + rc = -EFAULT; + goto out; + } + + if (rc != be32_to_cpu(header->length)) + goto out; + out: if (chip->dev.parent) pm_runtime_put_sync(chip->dev.parent); @@ -438,19 +448,13 @@ ssize_t tpm_transmit_cmd(struct tpm_chip *chip, const void *buf, size_t bufsiz, size_t min_rsp_body_length, unsigned int flags, const char *desc) { - const struct tpm_output_header *header; + const struct tpm_output_header *header = buf; int err; ssize_t len; len = tpm_transmit(chip, (const u8 *)buf, bufsiz, flags); if (len < 0) return len; - else if (len < TPM_HEADER_SIZE) - return -EFAULT; - - header = buf; - if (len != be32_to_cpu(header->length)) - return -EFAULT; err = be32_to_cpu(header->return_code); if (err != 0 && desc) -- 2.9.3