From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751042AbdALUjA (ORCPT ); Thu, 12 Jan 2017 15:39:00 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:48591 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751008AbdALUi7 (ORCPT ); Thu, 12 Jan 2017 15:38:59 -0500 Subject: Re: [tpmdd-devel] [PATCH RFC v2 3/5] tpm: infrastructure for TPM spaces From: James Bottomley To: Jarkko Sakkinen , tpmdd-devel@lists.sourceforge.net Cc: open list , linux-security-module@vger.kernel.org Date: Thu, 12 Jan 2017 12:38:52 -0800 In-Reply-To: <20170112174612.9314-4-jarkko.sakkinen@linux.intel.com> References: <20170112174612.9314-1-jarkko.sakkinen@linux.intel.com> <20170112174612.9314-4-jarkko.sakkinen@linux.intel.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.16.5 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 17011220-0008-0000-0000-0000068B8825 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00006421; HX=3.00000240; KW=3.00000007; PH=3.00000004; SC=3.00000199; SDB=6.00806770; UDB=6.00392642; IPR=6.00584101; BA=6.00005052; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00013906; XFM=3.00000011; UTC=2017-01-12 20:38:57 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17011220-0009-0000-0000-00003E979028 Message-Id: <1484253532.5807.16.camel@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-01-12_14:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1612050000 definitions=main-1701120270 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2017-01-12 at 19:46 +0200, Jarkko Sakkinen wrote: > +static int tpm2_map_response(struct tpm_chip *chip, u32 cc, u8 *rsp, > size_t len) > +{ > + struct tpm_space *space = &chip->work_space; > + u32 phandle; > + u32 vhandle; > + u32 attrs; > + int i; > + int rc; > + > + if (!tpm2_find_cc_attrs(chip, cc, &attrs)) { > + /* should never happen */ > + dev_err(&chip->dev, "TPM returned a different CC: > 0x%04x\n", > + cc); > + rc = -EFAULT; > + goto out_err; > + } > + > + if (!((attrs >> TPM2_CC_ATTR_RHANDLE) & 1)) > + return 0; > + > + phandle = be32_to_cpup((__be32 *)&rsp[TPM_HEADER_SIZE]); I think we have to check the command return code here. We can't blindly fish handles out of the response if the TPM returned an error because they won't exist and we'll pull rubbish from the buffer. Incremental patch below. Note I think we should use get_unaligned_be32 because we're pulling a 32 bit word from something that's on byte 6 (so misaligned): some architectures will trigger an unaligned trap for this (it's not a problem: they trap handle it, it just slows down processing a lot). James --- commit d17ad905ff7b114f7efd23f930e9a541ccdf7621 Author: James Bottomley Date: Wed Jan 11 22:01:29 2017 -0800 check return code diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index 61422e6..8009ed4 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -90,6 +90,7 @@ enum tpm2_structures { }; enum tpm2_return_codes { + TPM2_RC_SUCCESS = 0x0000, TPM2_RC_HASH = 0x0083, /* RC_FMT1 */ TPM2_RC_HANDLE = 0x008B, TPM2_RC_INITIALIZE = 0x0100, /* RC_VER1 */ diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c index ca55feb..44e5501 100644 --- a/drivers/char/tpm/tpm2-space.c +++ b/drivers/char/tpm/tpm2-space.c @@ -16,6 +16,7 @@ */ #include +#include #include "tpm.h" enum tpm2_handle_types { @@ -167,9 +168,13 @@ static int tpm2_map_response(struct tpm_chip *chip, u32 cc, u8 *rsp, size_t len) u32 phandle; u32 vhandle; u32 attrs; + u32 return_code = get_unaligned_be32((__be32 *)&rsp[6]); int i; int rc; + if (return_code != TPM2_RC_SUCCESS) + return 0; + if (!tpm2_find_cc_attrs(chip, cc, &attrs)) { /* should never happen */ dev_err(&chip->dev, "TPM returned a different CC: 0x%04x\n",