Re: [PATCH] KEYS: trusted: allow module init if TPM is inactive or deactivated
From: Jarkko Sakkinen <hidden>
Date: 2019-07-11 19:48:21
Also in:
keyrings, linux-integrity, lkml
On Fri, Jul 05, 2019 at 06:37:35PM +0200, 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
avoid module dependency problems.
Unfortunately, this does not completely solve the issue, as there could be
a case where a TPM is found but is not functional (the TPM commands return
an error). Specifically, after the tpm_chip structure is returned by
tpm_default_chip() in init_trusted(), the execution terminates after
init_digests() returns -EFAULT (due to the fact that tpm_get_random()
returns a positive value, but less than TPM_MAX_DIGEST_SIZE).
This patch fixes the issue by ignoring the TPM_ERR_DEACTIVATED and
TPM_ERR_DISABLED errors.
Why allow trusted module to initialize if TPM is not functional?
Also:
err = tpm_transmit_cmd(chip, &buf,
offsetof(struct tpm2_get_random_out,
buffer),
"attempting get random");
if (err) {
if (err > 0)
err = -EIO;
goto out;
}
/Jarkko