3 files changed, 15 insertions, 27 deletions

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 1c92dbeef736..83ece5639f86 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -308,42 +308,34 @@ EXPORT_SYMBOL_GPL(tpm_pcr_read);
  * tpm_pcr_extend - extend a PCR value in SHA1 bank.
  * @chip:	a &struct tpm_chip instance, %NULL for the default chip
  * @pcr_idx:	the PCR to be retrieved
- * @hash:	the hash value used to extend the PCR value
+ * @digests:	array of tpm_digest structures used to extend PCRs
  *
- * Note: with TPM 2.0 extends also those banks for which no digest was
- * specified in order to prevent malicious use of those PCR banks.
+ * Note: callers must pass a digest for every allocated PCR bank, in the same
+ * order of the banks in chip->allocated_banks.
  *
  * Return: same as with tpm_transmit_cmd()
  */
-int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, const u8 *hash)
+int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx,
+		   struct tpm_digest *digests)
 {
 	int rc;
-	struct tpm_digest *digest_list;
 	int i;
 
 	chip = tpm_find_get_ops(chip);
 	if (!chip)
 		return -ENODEV;
 
-	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
-		digest_list = kcalloc(chip->nr_allocated_banks,
-				      sizeof(*digest_list), GFP_KERNEL);
-		if (!digest_list)
-			return -ENOMEM;
-
-		for (i = 0; i < chip->nr_allocated_banks; i++) {
-			digest_list[i].alg_id = chip->allocated_banks[i].alg_id;
-			memcpy(digest_list[i].digest, hash, TPM_DIGEST_SIZE);
-		}
+	for (i = 0; i < chip->nr_allocated_banks; i++)
+		if (digests[i].alg_id != chip->allocated_banks[i].alg_id)
+			return -EINVAL;
 
-		rc = tpm2_pcr_extend(chip, pcr_idx, chip->nr_allocated_banks,
-				     digest_list);
-		kfree(digest_list);
+	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
+		rc = tpm2_pcr_extend(chip, pcr_idx, digests);
 		tpm_put_ops(chip);
 		return rc;
 	}
 
-	rc = tpm1_pcr_extend(chip, pcr_idx, hash,
+	rc = tpm1_pcr_extend(chip, pcr_idx, digests[0].digest,
 			     "attempting extend a PCR value");
 	tpm_put_ops(chip);
 	return rc;
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 4f85ce909122..2cce072f25b5 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -441,7 +441,7 @@ static inline u32 tpm2_rc_value(u32 rc)
 int tpm2_get_timeouts(struct tpm_chip *chip);
 int tpm2_pcr_read(struct tpm_chip *chip, u32 pcr_idx,
 		  struct tpm_digest *digest, u16 *digest_size_ptr);
-int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, u32 count,
+int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx,
 		    struct tpm_digest *digests);
 int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max);
 void tpm2_flush_context(struct tpm_chip *chip, u32 handle);
diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index 6967f15a6585..e74c5b7b64bf 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -246,12 +246,11 @@ struct tpm2_null_auth_area {
  *
  * @chip:	TPM chip to use.
  * @pcr_idx:	index of the PCR.
- * @count:	number of digests passed.
  * @digests:	list of pcr banks and corresponding digest values to extend.
  *
  * Return: Same as with tpm_transmit_cmd.
  */
-int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, u32 count,
+int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx,
 		    struct tpm_digest *digests)
 {
 	struct tpm_buf buf;
@@ -259,9 +258,6 @@ int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, u32 count,
 	int rc;
 	int i;
 
-	if (count > chip->nr_allocated_banks)
-		return -EINVAL;
-
 	rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_PCR_EXTEND);
 	if (rc)
 		return rc;
@@ -276,9 +272,9 @@ int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, u32 count,
 	tpm_buf_append_u32(&buf, sizeof(struct tpm2_null_auth_area));
 	tpm_buf_append(&buf, (const unsigned char *)&auth_area,
 		       sizeof(auth_area));
-	tpm_buf_append_u32(&buf, count);
+	tpm_buf_append_u32(&buf, chip->nr_allocated_banks);
 
-	for (i = 0; i < count; i++) {
+	for (i = 0; i < chip->nr_allocated_banks; i++) {
 		tpm_buf_append_u16(&buf, digests[i].alg_id);
 		tpm_buf_append(&buf, (const unsigned char *)&digests[i].digest,
 			       chip->allocated_banks[i].digest_size);