tpm_tis: Fix check_locality for correct locality acquisition

The TPM TIS specification says the TPM signals the acquisition of locality
when the TMP_ACCESS_REQUEST_USE bit goes to one *and* the
TPM_ACCESS_REQUEST_USE bit goes to zero.  Currently we only check the
former not the latter, so check both.  Adding the check on
TPM_ACCESS_REQUEST_USE should fix the case where the locality is
re-requested before the TPM has released it.  In this case the locality may
get released briefly before it is reacquired, which causes all sorts of
problems. However, with the added check, TPM_ACCESS_REQUEST_USE should
remain 1 until the second request for the locality is granted.

Cc: stable@ger.kernel.org
Fixes: 27084efee0c3 ("[PATCH] tpm: driver for next generation TPM chips")
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index 92c51c6cfd1b781efde95cea0e9aacba3776924c..f3ecde8df47d0546f33a56dd12eaa098b5b6a8a1 100644 (file)
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -125,7 +125,8 @@ static bool check_locality(struct tpm_chip *chip, int l)
        if (rc < 0)
                return false;
 
-       if ((access & (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) ==
+       if ((access & (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID
+                      | TPM_ACCESS_REQUEST_USE)) ==
            (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) {
                priv->locality = l;
                return true;