tpm: fix: set continueSession attribute for the unseal operation

It's better to set the continueSession attribute for the unseal
operation so that the session object is not removed as a side-effect
when the operation is successful. Since a user process created the
session, it should be also decide when the session is destroyed.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Fixes: 5beb0c435b ("keys, trusted: seal with a TPM2 authorization policy")

1 files changed, 7 insertions, 3 deletions

diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index 66e04b41a73d..b28e4da3d2cf 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -20,7 +20,11 @@
 #include <keys/trusted-type.h>
 
 enum tpm2_object_attributes {
-        TPM2_ATTR_USER_WITH_AUTH        = BIT(6),
+        TPM2_OA_USER_WITH_AUTH          = BIT(6),
+};
+
+enum tpm2_session_attributes {
+        TPM2_SA_CONTINUE_SESSION        = BIT(0),
 };
 
 struct tpm2_startup_in {
@@ -489,7 +493,7 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
                 tpm_buf_append(&buf, options->policydigest,
                                options->policydigest_len);
         } else {
-                tpm_buf_append_u32(&buf, TPM2_ATTR_USER_WITH_AUTH);
+                tpm_buf_append_u32(&buf, TPM2_OA_USER_WITH_AUTH);
                 tpm_buf_append_u16(&buf, 0);
         }
 
@@ -627,7 +631,7 @@ static int tpm2_unseal(struct tpm_chip *chip,
                              options->policyhandle ?
                              options->policyhandle : TPM2_RS_PW,
                              NULL /* nonce */, 0,
-                             0 /* session_attributes */,
+                             TPM2_SA_CONTINUE_SESSION,
                              options->blobauth /* hmac */,
                              TPM_DIGEST_SIZE);