linux-toradex.git/drivers/char/tpm/tpm1-cmd.c, branch v6.11

tpm: Add upgrade/reduced mode support for TPM1.2 modules

2022-08-03T20:56:19+00:00

In case a TPM in failure mode is detected, the TPM should be accessible
through a transparent communication channel for analysing purposes (e.g.
TPM_GetTestResult) or a field upgrade. Since a TPM in failure mode has
similar reduced functionality as in field upgrade mode, the flag
TPM_CHIP_FLAG_FIRMWARE_UPGRADE is also valid.

As described in TCG TPM Main Part1 Design Principles, Revision 116,
chapter 9.2.1. the TPM also allows an update function in case a TPM is
in failure mode.

If the TPM in failure mode is detected, the function tpm1_auto_startup()
sets TPM_CHIP_FLAG_FIRMWARE_UPGRADE flag, which is used later during
driver initialization/deinitialization to disable functionality which
makes no sense or will fail in the current TPM state. The following
functionality is affected:
 * Do not register TPM as a hwrng
 * Do not get pcr allocation
 * Do not register sysfs entries which provide information impossible to
   obtain in limited mode

Signed-off-by: Stefan Mahnke-Hartmann 
Reviewed-by: Jarkko Sakkinen 
Signed-off-by: Jarkko Sakkinen

tpm: fix some doc warnings in tpm1-cmd.c

2021-06-23T13:51:03+00:00

Fix the following make W=1 warnings:

  drivers/char/tpm/tpm1-cmd.c:325: warning: expecting prototype for tpm_startup(). Prototype was for tpm1_startup() instead
  drivers/char/tpm/tpm1-cmd.c:621: warning: expecting prototype for tpm_continue_selftest(). Prototype was for tpm1_continue_selftest() instead

Signed-off-by: Yang Yingliang 
Reviewed-by: Jarkko Sakkinen 
Signed-off-by: Jarkko Sakkinen

tpm: provide a way to override the chip returned durations

2019-11-12T19:45:36+00:00

Patch adds method ->update_durations to override returned
durations in case TPM chip misbehaves for TPM 1.2 drivers.

Cc: Peter Huewe 
Cc: Jason Gunthorpe 
Signed-off-by: Alexey Klimov 
Signed-off-by: Jerry Snitselaar 
Reviewed-by: Jarkko Sakkinen 
Tested-by: Jarkko Sakkinen  (!update_durations path)
Signed-off-by: Jarkko Sakkinen

tpm: tpm_ibm_vtpm: Fix unallocated banks

2019-08-04T21:55:00+00:00

The nr_allocated_banks and allocated banks are initialized as part of
tpm_chip_register. Currently, this is done as part of auto startup
function. However, some drivers, like the ibm vtpm driver, do not run
auto startup during initialization. This results in uninitialized memory
issue and causes a kernel panic during boot.

This patch moves the pcr allocation outside the auto startup function
into tpm_chip_register. This ensures that allocated banks are initialized
in any case.

Fixes: 879b589210a9 ("tpm: retrieve digest size of unknown algorithms with PCR read")
Reported-by: Michal Suchanek 
Signed-off-by: Nayna Jain 
Reviewed-by: Mimi Zohar 
Tested-by: Sachin Sant 
Tested-by: Michal Suchánek 
Reviewed-by: Jarkko Sakkinen 
Signed-off-by: Jarkko Sakkinen

tpm: Actually fail on TPM errors during "get random"

2019-06-24T20:57:49+00:00

A "get random" may fail with a TPM error, but those codes were returned
as-is to the caller, which assumed the result was the number of bytes
that had been written to the target buffer, which could lead to a kernel
heap memory exposure and over-read.

This fixes tpm1_get_random() to mask positive TPM errors into -EIO, as
before.

[   18.092103] tpm tpm0: A TPM error (379) occurred attempting get random
[   18.092106] usercopy: Kernel memory exposure attempt detected from SLUB object 'kmalloc-64' (offset 0, size 379)!

Link: https://bugzilla.redhat.com/show_bug.cgi?id=1650989
Reported-by: Phil Baker 
Reported-by: Craig Robson 
Fixes: 7aee9c52d7ac ("tpm: tpm1: rewrite tpm1_get_random() using tpm_buf structure")
Cc: Laura Abbott 
Cc: Tomas Winkler 
Cc: Jarkko Sakkinen 
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook 
Reviewed-by: Tomas Winkler 
Tested-by: Bartosz Szczepanek 
Reviewed-by: Jarkko Sakkinen 
Signed-off-by: Jarkko Sakkinen

tpm: retrieve digest size of unknown algorithms with PCR read

2019-02-13T07:48:51+00:00

Currently, the TPM driver retrieves the digest size from a table mapping
TPM algorithms identifiers to identifiers defined by the crypto subsystem.
If the algorithm is not defined by the latter, the digest size can be
retrieved from the output of the PCR read command.

The patch modifies the definition of tpm_pcr_read() and tpm2_pcr_read() to
pass the desired hash algorithm and obtain the digest size at TPM startup.
Algorithms and corresponding digest sizes are stored in the new structure
tpm_bank_info, member of tpm_chip, so that the information can be used by
other kernel subsystems.

tpm_bank_info contains: the TPM algorithm identifier, necessary to generate
the event log as defined by Trusted Computing Group (TCG); the digest size,
to pad/truncate a digest calculated with a different algorithm; the crypto
subsystem identifier, to calculate the digest of event data.

This patch also protects against data corruption that could happen in the
bus, by checking that the digest size returned by the TPM during a PCR read
matches the size of the algorithm passed to tpm2_pcr_read().

For the initial PCR read, when digest sizes are not yet available, this
patch ensures that the amount of data copied from the output returned by
the TPM does not exceed the size of the array data are copied to.

Signed-off-by: Roberto Sassu 
Reviewed-by: Jarkko Sakkinen 
Tested-by: Jarkko Sakkinen 
Acked-by: Mimi Zohar 
Signed-off-by: Jarkko Sakkinen

tpm: rename and export tpm2_digest and tpm2_algorithms

2019-02-13T07:48:51+00:00

Rename tpm2_* to tpm_* and move the definitions to include/linux/tpm.h so
that these can be used by other kernel subsystems (e.g. IMA).

Also, set the length of the digest array in tpm_digest to a new constant
named TPM_MAX_DIGEST_SIZE, equal to SHA512_DIGEST_SIZE.

Signed-off-by: Roberto Sassu 
Reviewed-by: Jarkko Sakkinen 
Tested-by: Jarkko Sakkinen 
Acked-by: Mimi Zohar 
Signed-off-by: Jarkko Sakkinen

tpm: dynamically allocate the allocated_banks array

2019-02-13T07:48:50+00:00

This patch renames active_banks (member of tpm_chip) to allocated_banks,
stores the number of allocated PCR banks in nr_allocated_banks (new member
of tpm_chip), and replaces the static array with a pointer to a dynamically
allocated array.

tpm2_get_pcr_allocation() determines if a PCR bank is allocated by checking
the mask in the TPML_PCR_SELECTION structure returned by the TPM for
TPM2_Get_Capability(). If a bank is not allocated, the TPM returns that
bank in TPML_PCR_SELECTION, with all bits in the mask set to zero. In this
case, the bank is not included in chip->allocated_banks, to avoid that TPM
driver users unnecessarily calculate a digest for that bank.

One PCR bank with algorithm set to SHA1 is always allocated for TPM 1.x.

As a consequence of the introduction of nr_allocated_banks,
tpm_pcr_extend() does not check anymore if the algorithm stored in tpm_chip
is equal to zero.

Signed-off-by: Roberto Sassu 
Tested-by: Jarkko Sakkinen 
Reviewed-by: Jarkko Sakkinen 
Signed-off-by: Jarkko Sakkinen

tpm: remove @flags from tpm_transmit()

2019-02-13T07:48:46+00:00

Remove @flags from tpm_transmit() API. It is no longer used for
anything.

Signed-off-by: Jarkko Sakkinen 
Reviewed-by: Stefan Berger 
Tested-by: Stefan Berger 
Reviewed-by: Jerry Snitselaar 
Reviewed-by: James Bottomley 
Tested-by: Alexander Steffen

tpm: remove @space from tpm_transmit()

2019-02-13T07:48:12+00:00

Remove @space from tpm_transmit() API` in order to completely remove the
bound between low-level transmission functionality and TPM spaces. The
only real dependency existing is the amount of data saved before trying
to send a command to the TPM.

It doesn't really matter if we save always a bit more than needed so
this commit changes the amount saved always to be the size of the TPM
header and three handles.

Cc: James Bottomley 
Signed-off-by: Jarkko Sakkinen 
Reviewed-by: Stefan Berger 
Tested-by: Stefan Berger 
Reviewed-by: Jerry Snitselaar 
Reviewed-by: James Bottomley 
Tested-by: Alexander Steffen