KEYS: trusted: correctly initialize digests and fix locking issue

Commit 0b6cf6b ("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: [email protected] Fixes: 0b6cf6b ("tpm: pass an array of tpm_extend_digest structures to tpm_pcr_extend()") Signed-off-by: Roberto Sassu <[email protected]> Suggested-by: Jarkko Sakkinen <[email protected]> Reviewed-by: Jerry Snitselaar <[email protected]> Reviewed-by: Jarkko Sakkinen <[email protected]> Signed-off-by: Jarkko Sakkinen <[email protected]>
IreneKnapp · Sep 24, 2019 · 9f75c82 · 9f75c82
1 parent 34cd83b
commit 9f75c82
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Showing 2 changed files with 14 additions and 5 deletions.
diff --git 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, u32 pcr_idx,
 	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;
 }

diff --git a/security/keys/trusted.c b/security/keys/trusted.c
@@ -1228,11 +1228,16 @@ static int __init trusted_shash_alloc(void)
 
 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;
 }