Re: [RFC PATCH v4] akcipher: new verify API for public key algorithms

[Herbert Xu]

On Fri, Jan 25, 2019 at 09:01:16PM +0300, Vitaly Chikunov wrote:
>
> @@ -781,36 +780,17 @@ static int tpm_key_verify_signature(const struct key *key,
>  	if (!req)
>  		goto error_free_tfm;
>  
> -	ret = -ENOMEM;
> -	outlen = crypto_akcipher_maxsize(tfm);
> -	output = kmalloc(outlen, GFP_KERNEL);
> -	if (!output)
> -		goto error_free_req;
> -
> -	sg_init_one(&sig_sg, sig->s, sig->s_size);
> -	sg_init_one(&digest_sg, output, outlen);
> -	akcipher_request_set_crypt(req, &sig_sg, &digest_sg, sig->s_size,
> -				   outlen);
> +	sg_init_table(&src_sg, 2);
> +	sg_set_buf(&src_sg[0], sig->s, sig->s_size);
> +	sg_set_buf(&src_sg[1], sig->digest, sig->digest_size);
> +	akcipher_request_set_crypt(req, &src_sg, NULL, sig->s_size,
> +				   sig->digest_size);

It's not clear that sig->digest is guaranteed to be kmalloc memory.
In any case, it's best not to mix unrelated changes in a single
patch.  So please keep the kmalloc on output and then copy
sig->digest into it and put output into the SG list.

Thanks,
-- 
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt