releases/4.9.28/tpm-fix-rc-value-check-in-tpm2_seal_trusted.patch

   1 From 7d761119a914ec0ac05ec2a5378d1f86e680967d Mon Sep 17 00:00:00 2001
   2 From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
   3 Date: Wed, 25 Jan 2017 23:00:22 +0200
   4 Subject: tpm: fix RC value check in tpm2_seal_trusted
   5
   6 From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
   7
   8 commit 7d761119a914ec0ac05ec2a5378d1f86e680967d upstream.
   9
  10 The error code handling is broken as any error code that has the same
  11 bits set as TPM_RC_HASH passes. Implemented tpm2_rc_value() helper to
  12 parse the error value from FMT0 and FMT1 error codes so that these types
  13 of mistakes are prevented in the future.
  14
  15 Fixes: 5ca4c20cfd37 ("keys, trusted: select hash algorithm for TPM2 chips")
  16 Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
  17 Reviewed-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
  18 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  19
  20 ---
  21  drivers/char/tpm/tpm.h      |    5 +++++
  22  drivers/char/tpm/tpm2-cmd.c |    2 +-
  23  2 files changed, 6 insertions(+), 1 deletion(-)
  24
  25 --- a/drivers/char/tpm/tpm.h
  26 +++ b/drivers/char/tpm/tpm.h
  27 @@ -518,6 +518,11 @@ static inline void tpm_add_ppi(struct tp
  28  }
  29  #endif
  30
  31 +static inline inline u32 tpm2_rc_value(u32 rc)
  32 +{
  33 +       return (rc & BIT(7)) ? rc & 0xff : rc;
  34 +}
  35 +
  36  int tpm2_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf);
  37  int tpm2_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash);
  38  int tpm2_get_random(struct tpm_chip *chip, u8 *out, size_t max);
  39 --- a/drivers/char/tpm/tpm2-cmd.c
  40 +++ b/drivers/char/tpm/tpm2-cmd.c
  41 @@ -529,7 +529,7 @@ out:
  42         tpm_buf_destroy(&buf);
  43
  44         if (rc > 0) {
  45 -               if ((rc & TPM2_RC_HASH) == TPM2_RC_HASH)
  46 +               if (tpm2_rc_value(rc) == TPM2_RC_HASH)
  47                         rc = -EINVAL;
  48                 else
  49                         rc = -EPERM;