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From:   Roberto Sassu <roberto.sassu@huawei.com>
To:     <zohar@linux.ibm.com>, <jarkko.sakkinen@linux.intel.com>,
        <james.bottomley@hansenpartnership.com>,
        <linux-integrity@vger.kernel.org>
CC:     <linux-security-module@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <silviu.vlasceanu@huawei.com>,
        Roberto Sassu <roberto.sassu@huawei.com>
Subject: [PATCH 1/8] tpm: initialize crypto_id of allocated_banks to HASH_ALGO__LAST
Date:   Mon, 27 Jan 2020 18:04:36 +0100
Message-ID: <20200127170443.21538-2-roberto.sassu@huawei.com>
In-Reply-To: <20200127170443.21538-1-roberto.sassu@huawei.com>
References: <20200127170443.21538-1-roberto.sassu@huawei.com>
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chip->allocated_banks contains the list of TPM algorithm IDs of allocated
PCR banks. It also contains the corresponding ID of the crypto subsystem,
so that users of the TPM driver can calculate a digest for a PCR extend
operation.

However, if there is no mapping between TPM algorithm ID and crypto ID, the
crypto_id field in chip->allocated_banks remains set to zero (the array is
allocated and initialized with kcalloc() in tpm2_get_pcr_allocation()).
Zero should not be used as value for unknown mappings, as it is a valid
crypto ID (HASH_ALGO_MD4).

This patch initializes crypto_id to HASH_ALGO__LAST.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
---
 drivers/char/tpm/tpm2-cmd.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index 13696deceae8..760329598b99 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -525,6 +525,8 @@ static int tpm2_init_bank_info(struct tpm_chip *chip, u32 bank_index)
 		return 0;
 	}
 
+	bank->crypto_id = HASH_ALGO__LAST;
+
 	return tpm2_pcr_read(chip, 0, &digest, &bank->digest_size);
 }
 
-- 
2.17.1