tpm: fix checks for policy digest existence in tpm2_seal_trusted()

In my original patch sealing with policy was done with dynamically
allocated buffer that I changed later into an array so the checks in
tpm2-cmd.c became invalid. This patch fixes the issue.

Fixes: 5beb0c435bdd ("keys, trusted: seal with a TPM2 authorization policy")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Acked-by: Peter Huewe <peterhuewe@gmx.de>

1 files changed, 4 insertions, 8 deletions

diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index 45a634016f95..66e04b41a73d 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -478,20 +478,16 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
         tpm_buf_append_u8(&buf, payload->migratable);
 
         /* public */
-        if (options->policydigest)
-                tpm_buf_append_u16(&buf, 14 + options->digest_len);
-        else
-                tpm_buf_append_u16(&buf, 14);
-
+        tpm_buf_append_u16(&buf, 14 + options->policydigest_len);
         tpm_buf_append_u16(&buf, TPM2_ALG_KEYEDHASH);
         tpm_buf_append_u16(&buf, hash);
 
         /* policy */
-        if (options->policydigest) {
+        if (options->policydigest_len) {
                 tpm_buf_append_u32(&buf, 0);
-                tpm_buf_append_u16(&buf, options->digest_len);
+                tpm_buf_append_u16(&buf, options->policydigest_len);
                 tpm_buf_append(&buf, options->policydigest,
-                               options->digest_len);
+                               options->policydigest_len);
         } else {
                 tpm_buf_append_u32(&buf, TPM2_ATTR_USER_WITH_AUTH);
                 tpm_buf_append_u16(&buf, 0);