When TPM2 log has entries with more than 3 digests, or with digests
not listed in the log header, log gets misparsed, eventually
leading to kernel complaint that code tried to vmalloc 512MB of
memory (I have no idea what would happen on bigger system).
So code should not parse only first 3 digests: both event header
and event itself are already in memory, so we can parse any number
of digests, as long as we do not try to parse whole memory when
given count of 0xFFFFFFFF.
So this change:
* Rejects event entry with more digests than log header describes.
Digest types should be unique, and all should be described in
log header, so there cannot be more digests in the event than in
the header.
* Reject event entry with digest that is not described in the
log header. In theory code could hardcode information about
digest IDs already assigned by TCG, but if firmware authors
cannot get event log format right, why should anyone believe
that they got event log content right.
Cc: stable@vger.kernel.org
Fixes: 4d23cc323c ("tpm: add securityfs support for TPM 2.0 firmware event log")
Signed-off-by: Petr Vandrovec <petr@vmware.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Unlike the device driver support for TPM 1.2, the TPM 2.0 does
not support the securityfs pseudo files for displaying the
firmware event log.
This patch enables support for providing the TPM 2.0 event log in
binary form. TPM 2.0 event log supports a crypto agile format that
records multiple digests, which is different from TPM 1.2. This
patch enables the tpm_bios_log_setup for TPM 2.0 and adds the
event log parser which understand the TPM 2.0 crypto agile format.
Signed-off-by: Nayna Jain <nayna@linux.vnet.ibm.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Kenneth Goldman <kgold@linux.vnet.ibm.com>
Tested-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Petr Vandrovec