Re: [PATCH v4 5/6] tpm: Increase TPM_BUFSIZE to 8kB for chunking support

[Jarkko Sakkinen]

On Mon, Oct 26, 2026 at 01:48:57AM +0530, Arun Menon wrote:
> From: Arun Menon <armenon@xxxxxxxxxx>
> 
> The size of the command is checked against TPM_BUFSIZE early on before
> even sending it to the backend. We therefore need to increase the
> TPM_BUFSIZE to allow support for larger commands.
> 
> For now, 8KB seems sufficient for ML-KEM and ML-DSA algorithms and it is
> also order-1 safe.
> 
> Signed-off-by: Arun Menon <armenon@xxxxxxxxxx>

In what timeline? Or is it out of spectrum timeline?

> ---
>  include/linux/tpm_command.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/include/linux/tpm_command.h b/include/linux/tpm_command.h
> index fc446a1282e2..4ad11068b090 100644
> --- a/include/linux/tpm_command.h
> +++ b/include/linux/tpm_command.h
> @@ -434,7 +434,7 @@ struct tpm2_context {
>   */
>  
>  #define TPM_DIGEST_SIZE		20	/* Max TPM v1.2 PCR size */
> -#define TPM_BUFSIZE		4096
> +#define TPM_BUFSIZE		8192
>  
>  /*
>   * SHA-512 is, as of today, the largest digest in the TCG algorithm repository.
> -- 
> 2.54.0
> 

Br, Jarkko