From: James Bottomley James.Bottomley@HansenPartnership.com
commit 3d9ae54af1d02a7c0edc55c77d7df2b921e58a87 upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/char/tpm/tpm_tis_core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -68,7 +68,8 @@ static bool check_locality(struct tpm_ch 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;