Re: [PATCH 2/6] security/keys/encrypted: Clean up request_trusted_key()

[Mimi Zohar]

On Mon, 2019-03-18 at 23:06 -0700, Dan Williams wrote:

< snip >

> +/*
> + * request_trusted_key - request the trusted key
> + *
> + * Trusted keys are sealed to PCRs and other metadata. Although userspace
> + * manages both trusted/encrypted key-types, like the encrypted key type
> + * data, trusted key type data is not visible decrypted from userspace.
> + */
> +static struct key *request_trusted_key(const char *trusted_desc,
> +				const u8 **master_key, size_t *master_keylen)
> +{
> +	struct trusted_key_payload *tpayload;
> +	struct key_type *type;
> +	struct key *tkey;
> +
> +	type = key_type_lookup("trusted");

The associated key_type_put() will need to be called.

> +	if (IS_ERR(type)) {
> +		tkey = (struct key *)type;
> +		goto error;
> +	}
> +	tkey = request_key(type, trusted_desc, NULL);
> +	if (IS_ERR(tkey))
> +		goto error;
> +
> +	down_read(&tkey->sem);
> +	tpayload = tkey->payload.data[0];
> +	*master_key = tpayload->key;
> +	*master_keylen = tpayload->key_len;
> +error:
> +	return tkey;
> +}
> +



> diff --git a/security/keys/key.c b/security/keys/key.c
> index 696f1c092c50..9045b62afb04 100644
> --- a/security/keys/key.c
> +++ b/security/keys/key.c
> @@ -706,6 +706,7 @@ struct key_type *key_type_lookup(const char *type)
>  found_kernel_type:
>  	return ktype;
>  }
> +EXPORT_SYMBOL_GPL(key_type_lookup);

Only the kernel is calling key_type_lookup(). ÂWhy does
key_type_lookup() need to be exported?

Mimi

>  
>  void key_set_timeout(struct key *key, unsigned timeout)
>  {
>