[PATCH] tpm2_load_command leaks memory

From: Dhiraj Shah
Date: Thu Jun 10 2021 - 05:50:27 EST


tpm2_key_decode allocates memory which is stored in blob and it's not freed.

Signed-off-by: Dhiraj Shah <find.dhiraj@xxxxxxxxx>
---
security/keys/trusted-keys/trusted_tpm2.c | 41 +++++++++++++++--------
1 file changed, 27 insertions(+), 14 deletions(-)

diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
index 0165da386289..52dd43bb8cdb 100644
--- a/security/keys/trusted-keys/trusted_tpm2.c
+++ b/security/keys/trusted-keys/trusted_tpm2.c
@@ -378,22 +378,31 @@ static int tpm2_load_cmd(struct tpm_chip *chip,
}

/* new format carries keyhandle but old format doesn't */
- if (!options->keyhandle)
- return -EINVAL;
+ if (!options->keyhandle) {
+ rc = -EINVAL;
+ goto err;
+ }

/* must be big enough for at least the two be16 size counts */
- if (payload->blob_len < 4)
- return -EINVAL;
+ if (payload->blob_len < 4) {
+ rc = -EINVAL;
+ goto err;
+ }

private_len = get_unaligned_be16(blob);

/* must be big enough for following public_len */
- if (private_len + 2 + 2 > (payload->blob_len))
- return -E2BIG;
+ if (private_len + 2 + 2 > (payload->blob_len)) {
+ rc = -E2BIG;
+ goto err;
+ }

public_len = get_unaligned_be16(blob + 2 + private_len);
- if (private_len + 2 + public_len + 2 > payload->blob_len)
- return -E2BIG;
+
+ if (private_len + 2 + public_len + 2 > payload->blob_len) {
+ rc = -E2BIG;
+ goto err;
+ }

pub = blob + 2 + private_len + 2;
/* key attributes are always at offset 4 */
@@ -406,13 +415,16 @@ static int tpm2_load_cmd(struct tpm_chip *chip,
payload->migratable = 1;

blob_len = private_len + public_len + 4;
- if (blob_len > payload->blob_len)
- return -E2BIG;

- rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_LOAD);
- if (rc)
- return rc;
+ if (blob_len > payload->blob_len) {
+ rc = -E2BIG;
+ goto err;
+ }

+ if (tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_LOAD) != 0)
+ rc = -ENOMEM;
+ goto out;
+ }
tpm_buf_append_u32(&buf, options->keyhandle);
tpm2_buf_append_auth(&buf, TPM2_RS_PW,
NULL /* nonce */, 0,
@@ -433,9 +445,10 @@ static int tpm2_load_cmd(struct tpm_chip *chip,
(__be32 *) &buf.data[TPM_HEADER_SIZE]);

out:
+ tpm_buf_destroy(&buf);
+err:
if (blob != payload->blob)
kfree(blob);
- tpm_buf_destroy(&buf);

if (rc > 0)
rc = -EPERM;
--
2.30.1 (Apple Git-130)