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: f221974525 ("security: keys: trusted: use ASN.1 TPM2 key format for the blobs")
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
This commit is contained in:
Jarkko Sakkinen 2024-05-20 02:31:53 +03:00
parent 8f6a15f095
commit ffcaa2172c

View File

@ -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 {