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    Subject[PATCH] security/keys/trusted: Allow operation without hardware TPM
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    Date
    Rather than fail initialization of the trusted.ko module, arrange for
    the module to load, but rely on trusted_instantiate() to fail
    trusted-key operations.

    Fixes: 240730437deb ("KEYS: trusted: explicitly use tpm_chip structure...")
    Cc: Roberto Sassu <roberto.sassu@huawei.com>
    Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
    Cc: James Bottomley <jejb@linux.ibm.com>
    Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
    Cc: Mimi Zohar <zohar@linux.ibm.com>
    Cc: David Howells <dhowells@redhat.com>
    Signed-off-by: Dan Williams <dan.j.williams@intel.com>
    ---
    security/keys/trusted.c | 21 +++++++++++++++++----
    1 file changed, 17 insertions(+), 4 deletions(-)

    diff --git a/security/keys/trusted.c b/security/keys/trusted.c
    index bcc9c6ead7fd..d959597a688e 100644
    --- a/security/keys/trusted.c
    +++ b/security/keys/trusted.c
    @@ -45,6 +45,13 @@ struct sdesc {
    static struct crypto_shash *hashalg;
    static struct crypto_shash *hmacalg;

    +static struct device *chip_dev(struct tpm_chip *chip)
    +{
    + if (chip)
    + return &chip->dev;
    + return NULL;
    +}
    +
    static struct sdesc *init_sdesc(struct crypto_shash *alg)
    {
    struct sdesc *sdesc;
    @@ -1224,6 +1231,14 @@ static int __init init_digests(void)
    int ret;
    int i;

    + /*
    + * Hardware tpm operations are disabled, but allow the software
    + * module to initialize, and depend on trusted_instantiate() to
    + * fail any attempts to access the missing hardware.
    + */
    + if (!chip)
    + return 0;
    +
    ret = tpm_get_random(chip, digest, TPM_MAX_DIGEST_SIZE);
    if (ret < 0)
    return ret;
    @@ -1246,8 +1261,6 @@ static int __init init_trusted(void)
    int ret;

    chip = tpm_default_chip();
    - if (!chip)
    - return -ENOENT;
    ret = init_digests();
    if (ret < 0)
    goto err_put;
    @@ -1263,13 +1276,13 @@ static int __init init_trusted(void)
    err_free:
    kfree(digests);
    err_put:
    - put_device(&chip->dev);
    + put_device(chip_dev(chip));
    return ret;
    }

    static void __exit cleanup_trusted(void)
    {
    - put_device(&chip->dev);
    + put_device(chip_dev(chip));
    kfree(digests);
    trusted_shash_release();
    unregister_key_type(&key_type_trusted);
    \
     
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      Last update: 2019-03-19 00:58    [W:8.886 / U:0.332 seconds]
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