Merge tag 'keys-trusted-next-6.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd

Pull key fixes from Jarkko Sakkinen:
 "Two bug fixes for a memory corruption bug and a memory leak bug in the
  DCP trusted keys type.

  Just as a reminder DCP was a crypto coprocessor in i.MX SoCs"

* tag 'keys-trusted-next-6.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd:
  KEYS: trusted: dcp: fix leak of blob encryption key
  KEYS: trusted: fix DCP blob payload length assignment

Author: torvalds

security/keys/trusted-keys/trusted_dcp.c

@@ -186,51 +186,58 @@ static int do_aead_crypto(u8 *in, u8 *out, size_t len, u8 *key, u8 *nonce,
 	return ret;
 }
 
-static int decrypt_blob_key(u8 *key)
+static int decrypt_blob_key(u8 *encrypted_key, u8 *plain_key)
 {
-	return do_dcp_crypto(key, key, false);
+	return do_dcp_crypto(encrypted_key, plain_key, false);
 }
 
-static int encrypt_blob_key(u8 *key)
+static int encrypt_blob_key(u8 *plain_key, u8 *encrypted_key)
 {
-	return do_dcp_crypto(key, key, true);
+	return do_dcp_crypto(plain_key, encrypted_key, true);
 }
 
 static int trusted_dcp_seal(struct trusted_key_payload *p, char *datablob)
 {
 	struct dcp_blob_fmt *b = (struct dcp_blob_fmt *)p->blob;
 	int blen, ret;
+	u8 plain_blob_key[AES_KEYSIZE_128];
 
 	blen = calc_blob_len(p->key_len);
 	if (blen > MAX_BLOB_SIZE)
 		return -E2BIG;
 
 	b->fmt_version = DCP_BLOB_VERSION;
 	get_random_bytes(b->nonce, AES_KEYSIZE_128);
-	get_random_bytes(b->blob_key, AES_KEYSIZE_128);
+	get_random_bytes(plain_blob_key, AES_KEYSIZE_128);
 
-	ret = do_aead_crypto(p->key, b->payload, p->key_len, b->blob_key,
+	ret = do_aead_crypto(p->key, b->payload, p->key_len, plain_blob_key,
 			     b->nonce, true);
 	if (ret) {
 		pr_err("Unable to encrypt blob payload: %i\n", ret);
-		return ret;
+		goto out;
 	}
 
-	ret = encrypt_blob_key(b->blob_key);
+	ret = encrypt_blob_key(plain_blob_key, b->blob_key);
 	if (ret) {
 		pr_err("Unable to encrypt blob key: %i\n", ret);
-		return ret;
+		goto out;
 	}
 
-	b->payload_len = get_unaligned_le32(&p->key_len);
+	put_unaligned_le32(p->key_len, &b->payload_len);
 	p->blob_len = blen;
-	return 0;
+	ret = 0;
+
+out:
+	memzero_explicit(plain_blob_key, sizeof(plain_blob_key));
+
+	return ret;
 }
 
 static int trusted_dcp_unseal(struct trusted_key_payload *p, char *datablob)
 {
 	struct dcp_blob_fmt *b = (struct dcp_blob_fmt *)p->blob;
 	int blen, ret;
+	u8 plain_blob_key[AES_KEYSIZE_128];
 
 	if (b->fmt_version != DCP_BLOB_VERSION) {
 		pr_err("DCP blob has bad version: %i, expected %i\n",
@@ -248,21 +255,23 @@ static int trusted_dcp_unseal(struct trusted_key_payload *p, char *datablob)
 		goto out;
 	}
 
-	ret = decrypt_blob_key(b->blob_key);
+	ret = decrypt_blob_key(b->blob_key, plain_blob_key);
 	if (ret) {
 		pr_err("Unable to decrypt blob key: %i\n", ret);
 		goto out;
 	}
 
 	ret = do_aead_crypto(b->payload, p->key, p->key_len + DCP_BLOB_AUTHLEN,
-			     b->blob_key, b->nonce, false);
+			     plain_blob_key, b->nonce, false);
 	if (ret) {
 		pr_err("Unwrap of DCP payload failed: %i\n", ret);
 		goto out;
 	}
 
 	ret = 0;
 out:
+	memzero_explicit(plain_blob_key, sizeof(plain_blob_key));
+
 	return ret;
 }