Re: [PATCH] efi/libstub: measure initrd to PCR9 independent of source

[Ard Biesheuvel]

(cc Ilias)

On Tue, 1 Oct 2024 at 05:20, Jeremy Linton <jeremy.linton@xxxxxxx> wrote:
>
> Currently the initrd is only measured if it can be loaded using the
> INITRD_MEDIA_GUID, if we are loading it from a path provided via the
> command line it is never measured. Lets move the check down a couple
> lines so the measurement happens independent of the source.
>
> Signed-off-by: Jeremy Linton <jeremy.linton@xxxxxxx>
> ---
>  drivers/firmware/efi/libstub/efi-stub-helper.c | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/firmware/efi/libstub/efi-stub-helper.c b/drivers/firmware/efi/libstub/efi-stub-helper.c
> index de659f6a815f..555f84287f0b 100644
> --- a/drivers/firmware/efi/libstub/efi-stub-helper.c
> +++ b/drivers/firmware/efi/libstub/efi-stub-helper.c
> @@ -621,10 +621,6 @@ efi_status_t efi_load_initrd(efi_loaded_image_t *image,
>         status = efi_load_initrd_dev_path(&initrd, hard_limit);
>         if (status == EFI_SUCCESS) {
>                 efi_info("Loaded initrd from LINUX_EFI_INITRD_MEDIA_GUID device path\n");
> -               if (initrd.size > 0 &&
> -                   efi_measure_tagged_event(initrd.base, initrd.size,
> -                                            EFISTUB_EVT_INITRD) == EFI_SUCCESS)
> -                       efi_info("Measured initrd data into PCR 9\n");
>         } else if (status == EFI_NOT_FOUND) {
>                 status = efi_load_initrd_cmdline(image, &initrd, soft_limit,
>                                                  hard_limit);
> @@ -637,6 +633,11 @@ efi_status_t efi_load_initrd(efi_loaded_image_t *image,
>         if (status != EFI_SUCCESS)
>                 goto failed;
>
> +       if (initrd.size > 0 &&
> +           efi_measure_tagged_event(initrd.base, initrd.size,
> +                                    EFISTUB_EVT_INITRD) == EFI_SUCCESS)
> +               efi_info("Measured initrd data into PCR 9\n");
> +
>         status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, sizeof(initrd),
>                              (void **)&tbl);
>         if (status != EFI_SUCCESS)
> --
> 2.46.1
>