[PATCH 4/5] efi_loader: fix GetInfo and SetInfo

[Ilias Apalodimas]

On Sat, 26 Oct 2024 at 09:41, Heinrich Schuchardt
<heinrich.schuchardt at canonical.com> wrote:
>
> * Some of our file system drivers cannot report a file size for
>   directories. Use a dummy value in this case.
> * For SetInfo the UEFI spec requires to ignore the file size field.
>
> Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt at canonical.com>
> ---
>  lib/efi_loader/efi_file.c | 30 ++++++++++++++++++++----------
>  1 file changed, 20 insertions(+), 10 deletions(-)
>
> diff --git a/lib/efi_loader/efi_file.c b/lib/efi_loader/efi_file.c
> index c92d8ccf004..95b3c890ee9 100644
> --- a/lib/efi_loader/efi_file.c
> +++ b/lib/efi_loader/efi_file.c
> @@ -864,8 +864,16 @@ static efi_status_t EFIAPI efi_file_getinfo(struct efi_file_handle *file,
>                 }
>
>                 ret = efi_get_file_size(fh, &file_size);
> -               if (ret != EFI_SUCCESS)
> -                       goto error;
> +               if (ret != EFI_SUCCESS) {
> +                       if (!fh->isdir)
> +                               goto error;
> +                       /*
> +                        * Some file drivers don't implement fs_size() for
> +                        * directories. Use a dummy non-zero value.
> +                        */
> +                       file_size = 4096;
> +                       ret = EFI_SUCCESS;
> +               }
>
>                 memset(info, 0, required_size);
>
> @@ -976,14 +984,16 @@ static efi_status_t EFIAPI efi_file_setinfo(struct efi_file_handle *file,
>                 }
>                 free(new_file_name);
>                 /* Check for truncation */
> -               ret = efi_get_file_size(fh, &file_size);
> -               if (ret != EFI_SUCCESS)
> -                       goto out;
> -               if (file_size != info->file_size) {
> -                       /* TODO: we do not support truncation */
> -                       EFI_PRINT("Truncation not supported\n");
> -                       ret = EFI_ACCESS_DENIED;
> -                       goto out;
> +               if (!fh->isdir) {
> +                       ret = efi_get_file_size(fh, &file_size);
> +                       if (ret != EFI_SUCCESS)
> +                               goto out;
> +                       if (file_size != info->file_size) {
> +                               /* TODO: we do not support truncation */
> +                               EFI_PRINT("Truncation not supported\n");
> +                               ret = EFI_ACCESS_DENIED;
> +                               goto out;
> +                       }
>                 }
>                 /*
>                  * We do not care for the other attributes
> --
> 2.45.2
>

Reviewed-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>