linux-kernel - Re: [PATCH v12 2/3] selftests: tdx: Test TDX attestation GetReport support

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Thu, 8 Sep 2022 22:08:35 -0700
From:   Sathyanarayanan Kuppuswamy 
        <sathyanarayanan.kuppuswamy@...ux.intel.com>
To:     "Huang, Kai" <kai.huang@...el.com>,
        "tglx@...utronix.de" <tglx@...utronix.de>,
        "mingo@...hat.com" <mingo@...hat.com>,
        "shuah@...nel.org" <shuah@...nel.org>,
        "x86@...nel.org" <x86@...nel.org>, "bp@...en8.de" <bp@...en8.de>,
        "dave.hansen@...ux.intel.com" <dave.hansen@...ux.intel.com>
Cc:     "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "ak@...ux.intel.com" <ak@...ux.intel.com>,
        "gregkh@...uxfoundation.org" <gregkh@...uxfoundation.org>,
        "wander@...hat.com" <wander@...hat.com>,
        "tim.gardner@...onical.com" <tim.gardner@...onical.com>,
        "hpa@...or.com" <hpa@...or.com>,
        "isaku.yamahata@...il.com" <isaku.yamahata@...il.com>,
        "kirill.shutemov@...ux.intel.com" <kirill.shutemov@...ux.intel.com>,
        "Luck, Tony" <tony.luck@...el.com>,
        "khalid.elmously@...onical.com" <khalid.elmously@...onical.com>,
        "marcelo.cerri@...onical.com" <marcelo.cerri@...onical.com>,
        "Cox, Philip" <philip.cox@...onical.com>,
        "linux-doc@...r.kernel.org" <linux-doc@...r.kernel.org>,
        "linux-kselftest@...r.kernel.org" <linux-kselftest@...r.kernel.org>
Subject: Re: [PATCH v12 2/3] selftests: tdx: Test TDX attestation GetReport
 support



On 9/8/22 8:48 PM, Huang, Kai wrote:
> On Wed, 2022-09-07 at 17:27 -0700, Kuppuswamy Sathyanarayanan wrote:
>> +TEST(verify_report)
>> +{
>> +	__u8 reportdata[TDX_REPORTDATA_LEN];
>> +	struct tdreport tdreport;
>> +	struct tdx_report_req req;
>> +	int devfd, i;
>> +
>> +	devfd = open(TDX_GUEST_DEVNAME, O_RDWR | O_SYNC);
>> +
>> +	ASSERT_LT(0, devfd);
>> +
>> +	/* Generate sample report data */
>> +	for (i = 0; i < TDX_REPORTDATA_LEN; i++)
>> +		reportdata[i] = i;
>> +
>> +	/* Initialize IOCTL request */
>> +	req.subtype     = 0;
>> +	req.reportdata  = (__u64)reportdata;
>> +	req.rpd_len     = TDX_REPORTDATA_LEN;
>> +	req.tdreport    = (__u64)&tdreport;
>> +	req.tdr_len     = sizeof(tdreport);
>> +
> 
> 'req' is a local variable, which isn't guaranteed to be zero. Looks you need to
> explicitly clear 'req' otherwise the req.reserved[7] may not be zero.

In the next version, I explicitly set it to 0. I could initialize the struct to
0. But doing it explicitly will show the expected values clearly.

memset(req.reserved, 0, sizeof(req.reserved));

> 

-- 
Sathyanarayanan Kuppuswamy
Linux Kernel Developer