Re: [PATCH 1/2] tpm: Move tpm_get_random api into the TPM devicedriver

[H. Peter Anvin]

On 06/07/2012 11:47 AM, Kent Yoder wrote:
> Move the tpm_get_random api from the trusted keys code into the TPM
> device driver itself so that other callers can make use of it. Also,
> change the api slightly so that the number of bytes read is returned in
> the call, since the TPM command can potentially return fewer bytes than
> requested.
>
> Signed-off-by: Kent Yoder <key@xxxxxxxxxxxxxxxxxx>

> +int tpm_get_random(u32 chip_num, u8 *out, size_t *max)

/* ... */

>   	case Opt_new:
> -		ret = my_get_random(payload->key, payload->key_len);
> +		ret = tpm_get_random(TPM_ANY_NUM, payload->key,
> +				     &payload->key_len);

payload->key_len is unsigned int, not size_t; this causes an overwrite 
of blob_len on 64-bit platforms.

	-hpa


--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.

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