[PATCH] tpm: fix RC value check in tpm2_seal_trusted

[Jarkko Sakkinen]

Fixes: 5ca4c20cfd37 ("keys, trusted: select hash algorithm for TPM2 chips")
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
---
 drivers/char/tpm/tpm.h      | 5 +++++
 drivers/char/tpm/tpm2-cmd.c | 2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 4e5fb22..abc621e 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -523,6 +523,11 @@ static inline void tpm_add_ppi(struct tpm_chip *chip)
 }
 #endif
 
+static inline inline u32 tpm2_rc_value(u32 rc)
+{
+	return (rc & BIT(7)) ? rc & 0xff : rc;
+}
+
 int tpm2_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf);
 int tpm2_pcr_extend(struct tpm_chip *chip, int pcr_idx, u32 count,
 		    struct tpm2_digest *digests);
diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index 6c8174a..40b09ca 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -551,7 +551,7 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
 	tpm_buf_destroy(&buf);
 
 	if (rc > 0) {
-		if ((rc & TPM2_RC_HASH) == TPM2_RC_HASH)
+		if (tpm2_rc_value(rc) == TPM2_RC_HASH)
 			rc = -EINVAL;
 		else
 			rc = -EPERM;
-- 
2.9.3