Merge tag 'keys-trusted-next-6.10-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd

fa8151ca · Linus Torvalds <[email protected]> · 2024-05-21 10:04:02 -07:00

Pull trusted keys fixes from Jarkko Sakkinen:
 "These are two bugs I found from trusted keys while working on a new
  RSA key type for TPM2. Both originate form v5.13.

  The memory leak is more crucial but I don't think it is either good
  idea if kernel throws WARN when ASN.1 parser fails, even if it is
  related to programming error, as it is not that mature code yet.

  There's at least two WARN's in that code but I picked just the one
  more likely to trigger. Planning to fix the other one too over time"

* tag 'keys-trusted-next-6.10-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd:
  KEYS: trusted: Do not use WARN when encode fails
  KEYS: trusted: Fix memory leak in tpm2_key_encode()

Commit: fa8151cabfaa4166feeb6e8a4df428d7c3d9fecd
Parents: 38da32ee · 050bf3c7

Merge commit. Changes below are compared with the first parent: 38da32ee.

Changes

1 files changed · +19 −6

File	Status	Add	Del	Content
security/keys/trusted-keys/trusted_tpm2.c	modified	+19	−6	View file

security/keys/trusted-keys/trusted_tpm2.c

View file

diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
index dfeec06..8b7dd73 100644
--- a/security/keys/trusted-keys/trusted_tpm2.c
+++ b/security/keys/trusted-keys/trusted_tpm2.c
@@ -38,6 +38,7 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
 	u8 *end_work = scratch + SCRATCH_SIZE;
 	u8 *priv, *pub;
 	u16 priv_len, pub_len;
+	int ret;
 
 	priv_len = get_unaligned_be16(src) + 2;
 	priv = src;
@@ -57,8 +58,10 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
 		unsigned char bool[3], *w = bool;
 		/* tag 0 is emptyAuth */
 		w = asn1_encode_boolean(w, w + sizeof(bool), true);
-		if (WARN(IS_ERR(w), "BUG: Boolean failed to encode"))
-			return PTR_ERR(w);
+		if (WARN(IS_ERR(w), "BUG: Boolean failed to encode")) {
+			ret = PTR_ERR(w);
+			goto err;
+		}
 		work = asn1_encode_tag(work, end_work, 0, bool, w - bool);
 	}
 
@@ -69,8 +72,10 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
 	 * trigger, so if it does there's something nefarious going on
 	 */
 	if (WARN(work - scratch + pub_len + priv_len + 14 > SCRATCH_SIZE,
-		 "BUG: scratch buffer is too small"))
-		return -EINVAL;
+		 "BUG: scratch buffer is too small")) {
+		ret = -EINVAL;
+		goto err;
+	}
 
 	work = asn1_encode_integer(work, end_work, options->keyhandle);
 	work = asn1_encode_octet_string(work, end_work, pub, pub_len);
@@ -79,10 +84,18 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
 	work1 = payload->blob;
 	work1 = asn1_encode_sequence(work1, work1 + sizeof(payload->blob),
 				     scratch, work - scratch);
-	if (WARN(IS_ERR(work1), "BUG: ASN.1 encoder failed"))
-		return PTR_ERR(work1);
+	if (IS_ERR(work1)) {
+		ret = PTR_ERR(work1);
+		pr_err("BUG: ASN.1 encoder failed with %d\n", ret);
+		goto err;
+	}
 
+	kfree(scratch);
 	return work1 - payload->blob;
+
+err:
+	kfree(scratch);
+	return ret;
 }
 
 struct tpm2_key_context {