tpm2_load() allocates a blob indirectly via tpm2_key_decode() but it is not freed in all failure paths. Address this with a scope-based cleanup helper __free(). For legacy blobs, the implicit de-allocation is gets disable by no_free_ptr().

Cc: stable@vger.kernel.org # v5.13+ Fixes: f2219745250f ("security: keys: trusted: use ASN.1 TPM2 key format for the blobs") Signed-off-by: Jarkko Sakkinen jarkko@kernel.org --- v7: - Fix compiler warning. v6: - A new patch in this version. --- security/keys/trusted-keys/trusted_tpm2.c | 24 +++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c index 3205732fb4b7..00bc1afb32c8 100644 --- a/security/keys/trusted-keys/trusted_tpm2.c +++ b/security/keys/trusted-keys/trusted_tpm2.c @@ -98,9 +98,8 @@ struct tpm2_key_context { u32 priv_len; };

-static int tpm2_key_decode(struct trusted_key_payload *payload, - struct trusted_key_options *options, - u8 **buf) +static void *tpm2_key_decode(struct trusted_key_payload *payload, + struct trusted_key_options *options) { int ret; struct tpm2_key_context ctx; @@ -111,16 +110,15 @@ static int tpm2_key_decode(struct trusted_key_payload *payload, ret = asn1_ber_decoder(&tpm2key_decoder, &ctx, payload->blob, payload->blob_len); if (ret < 0) - return ret; + return ERR_PTR(ret);

if (ctx.priv_len + ctx.pub_len > MAX_BLOB_SIZE) - return -EINVAL; + return ERR_PTR(-EINVAL);

blob = kmalloc(ctx.priv_len + ctx.pub_len + 4, GFP_KERNEL); if (!blob) - return -ENOMEM; + return ERR_PTR(-ENOMEM);

- *buf = blob; options->keyhandle = ctx.parent;

memcpy(blob, ctx.priv, ctx.priv_len); @@ -128,7 +126,7 @@ static int tpm2_key_decode(struct trusted_key_payload *payload,

memcpy(blob, ctx.pub, ctx.pub_len);

- return 0; + return blob; }

int tpm2_key_parent(void *context, size_t hdrlen, @@ -372,6 +370,7 @@ static int tpm2_load_cmd(struct tpm_chip *chip, struct trusted_key_options *options, u32 *blob_handle) { + u8 *blob_ref __free(kfree) = NULL; struct tpm_buf buf; unsigned int private_len; unsigned int public_len; @@ -380,11 +379,14 @@ static int tpm2_load_cmd(struct tpm_chip *chip, int rc; u32 attrs;

- rc = tpm2_key_decode(payload, options, &blob); - if (rc) { + blob = tpm2_key_decode(payload, options); + if (IS_ERR(blob)) { /* old form */ blob = payload->blob; payload->old_format = 1; + } else { + /* Bind to cleanup: */ + blob_ref = blob; }

/* new format carries keyhandle but old format doesn't */ @@ -449,8 +451,6 @@ static int tpm2_load_cmd(struct tpm_chip *chip, (__be32 *) &buf.data[TPM_HEADER_SIZE]);

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

if (rc > 0)