From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751343AbdAQW2A (ORCPT ); Tue, 17 Jan 2017 17:28:00 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:46302 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751203AbdAQW15 (ORCPT ); Tue, 17 Jan 2017 17:27:57 -0500 Subject: Re: [PATCH v6] tpm: Check size of response before accessing data To: Jarkko Sakkinen References: <1484602871-20145-1-git-send-email-stefanb@linux.vnet.ibm.com> <20170117144905.4haeudj3v5ycohr3@intel.com> Cc: tpmdd-devel@lists.sourceforge.net, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org From: Stefan Berger Date: Tue, 17 Jan 2017 17:27:47 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.1.1 MIME-Version: 1.0 In-Reply-To: <20170117144905.4haeudj3v5ycohr3@intel.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 17011722-0056-0000-0000-0000027D8D46 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00006452; HX=3.00000240; KW=3.00000007; PH=3.00000004; SC=3.00000199; SDB=6.00809031; UDB=6.00394080; IPR=6.00586389; BA=6.00005066; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00013953; XFM=3.00000011; UTC=2017-01-17 22:27:54 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17011722-0057-0000-0000-000006B29F3B Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-01-17_15:,, 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-1701170296 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/17/2017 09:49 AM, Jarkko Sakkinen wrote: > On Mon, Jan 16, 2017 at 04:41:11PM -0500, Stefan Berger wrote: > >> + * @min_rx_length: minimum expected length of response > Please, rename as min_rsp_body_len and change the description > accordingly. > >> * @flags: tpm transmit flags - bitmap >> * @desc: command description used in the error message >> * >> @@ -434,25 +435,34 @@ ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz, >> * A positive number for a TPM error. >> */ >> ssize_t tpm_transmit_cmd(struct tpm_chip *chip, const void *cmd, >> - int len, unsigned int flags, const char *desc) >> + size_t cmd_length, size_t min_rx_length, >> + unsigned int flags, const char *desc) >> { >> const struct tpm_output_header *header; >> int err; >> + ssize_t len; >> >> - len = tpm_transmit(chip, (const u8 *)cmd, len, flags); >> + len = tpm_transmit(chip, (const u8 *)cmd, cmd_length, flags); >> if (len < 0) >> return len; >> else if (len < TPM_HEADER_SIZE) >> return -EFAULT; >> >> header = cmd; >> + if (len < be32_to_cpu(header->length)) >> + return -EFAULT; >> >> err = be32_to_cpu(header->return_code); >> if (err != 0 && desc) >> dev_err(&chip->dev, "A TPM error (%d) occurred %s\n", err, >> desc); >> + if (err) >> + return err; >> >> - return err; >> + if (be32_to_cpu(header->length) < min_rx_length) >> + return -EFAULT; >> + >> + return 0; >> } >> >> #define TPM_DIGEST_SIZE 20 >> @@ -468,7 +478,7 @@ static const struct tpm_input_header tpm_getcap_header = { >> }; >> >> ssize_t tpm_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap, >> - const char *desc) >> + const char *desc, size_t min_cap_length) > tpm_getcap update should be its own commit. tpm_getcap needs to pass something as min_rsp_body_length to tpm_transmit_cmd. What would it pass?