Commit ffcaa217 authored by Jarkko Sakkinen's avatar Jarkko Sakkinen
Browse files

KEYS: trusted: Fix memory leak in tpm2_key_encode() 



'scratch' is never freed. Fix this by calling kfree() in the success, and
in the error case.

Cc: stable@vger.kernel.org # +v5.13
Fixes: f2219745 ("security: keys: trusted: use ASN.1 TPM2 key format for the blobs")
Signed-off-by: default avatarJarkko Sakkinen <jarkko@kernel.org>
parent 8f6a15f0

security/keys/trusted-keys/trusted_tpm2.c

+18 −6
Original line number Diff line number Diff line
@@ -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 +84,17 @@ 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 (WARN(IS_ERR(work1), "BUG: ASN.1 encoder failed")) {

		ret = PTR_ERR(work1);

		goto err;

	}



	kfree(scratch);

	return work1 - payload->blob;



err:

	kfree(scratch);

	return ret;

}



struct tpm2_key_context {