Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: [PATCH v3 7/8] ima: Calculate and extend PCR with digests in
 ima_template_entry
From:   Mimi Zohar <zohar@linux.ibm.com>
To:     Roberto Sassu <roberto.sassu@huawei.com>,
        James.Bottomley@HansenPartnership.com,
        jarkko.sakkinen@linux.intel.com
Cc:     linux-integrity@vger.kernel.org,
        linux-security-module@vger.kernel.org,
        linux-kernel@vger.kernel.org, silviu.vlasceanu@huawei.com
Date:   Mon, 02 Mar 2020 23:03:42 -0500
In-Reply-To: <20200210100418.22049-1-roberto.sassu@huawei.com>
References: <20200210100418.22049-1-roberto.sassu@huawei.com>
Content-Type: text/plain; charset="UTF-8"
Mime-Version: 1.0
Content-Transfer-Encoding: 7bit
Message-Id: <1583208222.8544.168.camel@linux.ibm.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Mon, 2020-02-10 at 11:04 +0100, Roberto Sassu wrote:

> @@ -219,6 +214,8 @@ int ima_restore_measurement_entry(struct ima_template_entry *entry)
>  
>  int __init ima_init_digests(void)
>  {
> +	u16 digest_size;
> +	u16 crypto_id;
>  	int i;
>  
>  	if (!ima_tpm_chip)
> @@ -229,8 +226,17 @@ int __init ima_init_digests(void)
>  	if (!digests)
>  		return -ENOMEM;
>  
> -	for (i = 0; i < ima_tpm_chip->nr_allocated_banks; i++)
> +	for (i = 0; i < ima_tpm_chip->nr_allocated_banks; i++) {
>  		digests[i].alg_id = ima_tpm_chip->allocated_banks[i].alg_id;
> +		digest_size = ima_tpm_chip->allocated_banks[i].digest_size;
> +		crypto_id = ima_tpm_chip->allocated_banks[i].crypto_id;
> +
> +		/* for unmapped TPM algorithms digest is still a padded SHA1 */
> +		if (crypto_id == HASH_ALGO__LAST)
> +			digest_size = SHA1_DIGEST_SIZE;
> +
> +		memset(digests[i].digest, 0xff, digest_size);

Shouldn't the memset here be of the actual digest size even for
unmapped TPM algorithms.

> +	}
>  
>  	return 0;
>  }