[PATCH 5.2 271/313] KEYS: trusted: correctly initialize digests and fix locking issue

[Greg Kroah-Hartman]

From: Roberto Sassu <roberto.sassu@xxxxxxxxxx>

commit 9f75c82246313d4c2a6bc77e947b45655b3b5ad5 upstream.

Commit 0b6cf6b97b7e ("tpm: pass an array of tpm_extend_digest structures to
tpm_pcr_extend()") modifies tpm_pcr_extend() to accept a digest for each
PCR bank. After modification, tpm_pcr_extend() expects that digests are
passed in the same order as the algorithms set in chip->allocated_banks.

This patch fixes two issues introduced in the last iterations of the patch
set: missing initialization of the TPM algorithm ID in the tpm_digest
structures passed to tpm_pcr_extend() by the trusted key module, and
unreleased locks in the TPM driver due to returning from tpm_pcr_extend()
without calling tpm_put_ops().

Cc: stable@xxxxxxxxxxxxxxx
Fixes: 0b6cf6b97b7e ("tpm: pass an array of tpm_extend_digest structures to tpm_pcr_extend()")
Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
Suggested-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
Reviewed-by: Jerry Snitselaar <jsnitsel@xxxxxxxxxx>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/char/tpm/tpm-interface.c |   14 +++++++++-----
 security/keys/trusted.c          |    5 +++++
 2 files changed, 14 insertions(+), 5 deletions(-)

--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -320,18 +320,22 @@ int tpm_pcr_extend(struct tpm_chip *chip
 	if (!chip)
 		return -ENODEV;
 
-	for (i = 0; i < chip->nr_allocated_banks; i++)
-		if (digests[i].alg_id != chip->allocated_banks[i].alg_id)
-			return -EINVAL;
+	for (i = 0; i < chip->nr_allocated_banks; i++) {
+		if (digests[i].alg_id != chip->allocated_banks[i].alg_id) {
+			rc = EINVAL;
+			goto out;
+		}
+	}
 
 	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 		rc = tpm2_pcr_extend(chip, pcr_idx, digests);
-		tpm_put_ops(chip);
-		return rc;
+		goto out;
 	}
 
 	rc = tpm1_pcr_extend(chip, pcr_idx, digests[0].digest,
 			     "attempting extend a PCR value");
+
+out:
 	tpm_put_ops(chip);
 	return rc;
 }
--- a/security/keys/trusted.c
+++ b/security/keys/trusted.c
@@ -1228,11 +1228,16 @@ hashalg_fail:
 
 static int __init init_digests(void)
 {
+	int i;
+
 	digests = kcalloc(chip->nr_allocated_banks, sizeof(*digests),
 			  GFP_KERNEL);
 	if (!digests)
 		return -ENOMEM;
 
+	for (i = 0; i < chip->nr_allocated_banks; i++)
+		digests[i].alg_id = chip->allocated_banks[i].alg_id;
+
 	return 0;
 }