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Subject: Re: [PATCH v2] KEYS: trusted: allow module init if TPM is inactive or
 deactivated
To:     Tyler Hicks <tyhicks@canonical.com>
CC:     <jarkko.sakkinen@linux.intel.com>, <jejb@linux.ibm.com>,
        <zohar@linux.ibm.com>, <jgg@ziepe.ca>,
        <linux-integrity@vger.kernel.org>,
        <linux-security-module@vger.kernel.org>,
        <keyrings@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <crazyt2019+lml@gmail.com>, <nayna@linux.vnet.ibm.com>,
        <silviu.vlasceanu@huawei.com>
References: <20190802150733.1972-1-roberto.sassu@huawei.com>
 <20190802153030.GB26616@elm>
From:   Roberto Sassu <roberto.sassu@huawei.com>
Message-ID: <3222714a-a280-0708-f4c0-5db6d342d8dc@huawei.com>
Date:   Fri, 2 Aug 2019 17:34:58 +0200
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On 8/2/2019 5:30 PM, Tyler Hicks wrote:
> On 2019-08-02 17:07:33, Roberto Sassu wrote:
>> Commit c78719203fc6 ("KEYS: trusted: allow trusted.ko to initialize w/o a
>> TPM") allows the trusted module to be loaded even a TPM is not found to
>                                                     ^ if
> 
>> avoid module dependency problems.
>>
>> However, trusted module initialization can still fail if the TPM is
>> inactive or deactivated. This patch ignores tpm_get_random() errors in
>> init_digests() and returns -EFAULT in pcrlock() if the TPM didn't return
>> random data.
>>
>> Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
> 
> The code changes look correct to me.
> 
>    Reviewed-by: Tyler Hicks <tyhicks@canonical.com>
> 
> For whoever takes this patch through their tree, I think that adding the
> following Fixes tag would be useful (as well as cc'ing stable):
> 
>    Fixes: 240730437deb ("KEYS: trusted: explicitly use tpm_chip structure...")
> 
> I think it is also worth leaving a short note, in the commit message,
> for backporters that commit 782779b60faa ("tpm: Actually fail on TPM
> errors during "get random"") should be included with any backports of
> this patch.

Right, thanks. I wait for Jarkko's comments and I add both the Fixes tag
and the short note in the next version of the patch.

Roberto

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