Re: [PATCH v9 6/6] tpm: pass an array of tpm_extend_digest structures to tpm_pcr_extend()

From: Roberto Sassu <roberto.sassu@huawei.com>
To: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: Mimi Zohar <zohar@linux.ibm.com>, <david.safford@ge.com>,
	<monty.wiseman@ge.com>, <matthewgarrett@google.com>,
	<linux-integrity@vger.kernel.org>,
	<linux-security-module@vger.kernel.org>,
	<keyrings@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
	<silviu.vlasceanu@huawei.com>
Subject: Re: [PATCH v9 6/6] tpm: pass an array of tpm_extend_digest structures to tpm_pcr_extend()
Date: Mon, 4 Feb 2019 14:21:59 +0100	[thread overview]
Message-ID: <8b519a73-eb76-c700-69bc-17f7788cca08@huawei.com> (raw)
In-Reply-To: <20190204120746.GG26799@linux.intel.com>

On 2/4/2019 1:07 PM, Jarkko Sakkinen wrote:
> On Mon, Feb 04, 2019 at 10:14:38AM +0100, Roberto Sassu wrote:
>> On 2/1/2019 8:15 PM, Mimi Zohar wrote:
>>> Hi Roberto,
>>>
>>> Sorry for the delayed review.  A few comments inline below, minor
>>> suggestions.
>>>
>>>> diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
>>>> index cc12f3449a72..e6b2dcb0846a 100644
>>>> --- a/security/integrity/ima/ima.h
>>>> +++ b/security/integrity/ima/ima.h
>>>> @@ -56,6 +56,7 @@ extern int ima_policy_flag;
>>>>    extern int ima_hash_algo;
>>>>    extern int ima_appraise;
>>>>    extern struct tpm_chip *ima_tpm_chip;
>>>> +extern struct tpm_digest *digests;
>>>>    /* IMA event related data */
>>>>    struct ima_event_data {
>>>> diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c
>>>> index 6bb42a9c5e47..296a965b11ef 100644
>>>> --- a/security/integrity/ima/ima_init.c
>>>> +++ b/security/integrity/ima/ima_init.c
>>>> @@ -27,6 +27,7 @@
>>>>    /* name for boot aggregate entry */
>>>>    static const char boot_aggregate_name[] = "boot_aggregate";
>>>>    struct tpm_chip *ima_tpm_chip;
>>>> +struct tpm_digest *digests;
>>>
>>> "digests" is used in the new ima_init_digests() and in
>>> ima_pcr_extend().  It's nice that the initialization routines are
>>> grouped together here in ima_init.c, but wouldn't it better to define
>>> "digests" in ima_queued.c, where it is currently being used?
>>>    "digests" could then be defined as static.
>>
>> 'digests' and ima_init_digests() can be moved to ima_queue.c, but I have
>> to add the definition of ima_init_digests() to ima.h. Should I do it?
>>
>>
>>>>    /* Add the boot aggregate to the IMA measurement list and extend
>>>>     * the PCR register.
>>>> @@ -104,6 +105,24 @@ void __init ima_load_x509(void)
>>>>    }
>>>>    #endif
>>>> +int __init ima_init_digests(void)
>>>> +{
>>>> +	int i;
>>>> +
>>>> +	if (!ima_tpm_chip)
>>>> +		return 0;
>>>> +
>>>> +	digests = kcalloc(ima_tpm_chip->nr_allocated_banks, sizeof(*digests),
>>>> +			  GFP_NOFS);
>>>> +	if (!digests)
>>>> +		return -ENOMEM;
>>>> +
>>>> +	for (i = 0; i < ima_tpm_chip->nr_allocated_banks; i++)
>>>> +		digests[i].alg_id = ima_tpm_chip->allocated_banks[i].alg_id;
>>>> +
>>>> +	return 0;
>>>> +}
>>>> +
>>>>    int __init ima_init(void)
>>>>    {
>>>>    	int rc;
>>>> @@ -125,6 +144,9 @@ int __init ima_init(void)
>>>>    	ima_load_kexec_buffer();
>>>> +	rc = ima_init_digests();
>>>
>>> Ok. Getting the tpm chip is at the beginning of this function.
>>>    Deferring allocating "digests" to here, avoids having to free memory
>>> on failure.
>>>
>>> ima_load_kexec_buffer() restores prior measurements, but doesn't
>>> extend the TPM.  For anyone reading the code, a short comment above
>>> ima_load_kexec_buffer() would make sense.
>>
>> Ok. Should I resend the last patch again with the fixes you suggested?
> 
> Send the full patch set. For me it is easier then to apply the series
> rather than cherry-picking patches from random versions of the patch
> set.

I can include your fix in patch 4/6, if you prefer.

Roberto

> /Jarkko
> 

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