Re: [PATCH] efi_loader: capsule: remove authentication data

Please ignore this patch as I mistakenly sent out v1.

-Takahiro Akashi

On Tue, Jul 20, 2021 at 02:44:42PM +0900, AKASHI Takahiro wrote:

If capsule authentication is disabled and yet a capsule file is signed, its signature must be removed from image data to flush. Otherwise, the firmware will be corrupted after update.

Fixes: 04be98bd6bcf ("efi: capsule: Add support for uefi capsule authentication") Signed-off-by: AKASHI Takahiro takahiro.akashi@linaro.org

---

lib/efi_loader/efi_capsule.c | 70 +++++++++++++++++++++++++++++------- 1 file changed, 57 insertions(+), 13 deletions(-)

diff --git a/lib/efi_loader/efi_capsule.c b/lib/efi_loader/efi_capsule.c index b0dffd3ac9ce..5d156c730faa 100644 --- a/lib/efi_loader/efi_capsule.c +++ b/lib/efi_loader/efi_capsule.c @@ -206,6 +206,39 @@ skip: return NULL; }

+/**

• • efi_remove_auth_hdr - remove authentication data from image
• • @image: Pointer to pointer to Image
• • @image_size: Pointer to Image size
• • Remove the authentication data from image if possible.
• • Update @image and @image_size.
• • Return: status code
• */

+static efi_status_t efi_remove_auth_hdr(void **image, efi_uintn_t *image_size) +{

• struct efi_firmware_image_authentication *auth_hdr;
• efi_status_t ret = EFI_INVALID_PARAMETER;
• auth_hdr = (struct efi_firmware_image_authentication *)*image;
• if (*image_size < sizeof(*auth_hdr))

• goto out;
  

• if (auth_hdr->auth_info.hdr.dwLength <=

•    offsetof(struct win_certificate_uefi_guid, cert_data))
  

• goto out;
  

• *image = (uint8_t *)*image + sizeof(auth_hdr->monotonic_count) +

• auth_hdr->auth_info.hdr.dwLength;
  

• *image_size = *image_size - auth_hdr->auth_info.hdr.dwLength -

• sizeof(auth_hdr->monotonic_count);
  

• ret = EFI_SUCCESS;

+out:

• return ret;

+}

#if defined(CONFIG_EFI_CAPSULE_AUTHENTICATE)

#if defined(CONFIG_EFI_PKEY_DTB_EMBED) @@ -271,21 +304,15 @@ efi_status_t efi_capsule_authenticate(const void *capsule, efi_uintn_t capsule_s if (capsule == NULL || capsule_size == 0) goto out;

• auth_hdr = (struct efi_firmware_image_authentication *)capsule;
• if (capsule_size < sizeof(*auth_hdr))

• goto out;
  

• if (auth_hdr->auth_info.hdr.dwLength <=

•    offsetof(struct win_certificate_uefi_guid, cert_data))
  

• *image = (uint8_t *)capsule;

• *image_size = capsule_size;

• if (efi_remove_auth_hdr(image, image_size) != EFI_SUCCESS) goto out;

• auth_hdr = (struct efi_firmware_image_authentication *)capsule; if (guidcmp(&auth_hdr->auth_info.cert_type, &efi_guid_cert_type_pkcs7)) goto out;

• *image = (uint8_t *)capsule + sizeof(auth_hdr->monotonic_count) +

• auth_hdr->auth_info.hdr.dwLength;
  

• *image_size = capsule_size - auth_hdr->auth_info.hdr.dwLength -

• sizeof(auth_hdr->monotonic_count);
  

  memcpy(&monotonic_count, &auth_hdr->monotonic_count, sizeof(monotonic_count));

@@ -367,7 +394,7 @@ static efi_status_t efi_capsule_update_firmware( { struct efi_firmware_management_capsule_header *capsule; struct efi_firmware_management_capsule_image_header *image;

• size_t capsule_size;

• size_t capsule_size, image_binary_size; void *image_binary, *vendor_code; efi_handle_t *handles; efi_uintn_t no_handles;

@@ -429,13 +456,30 @@ static efi_status_t efi_capsule_update_firmware( }

/* do update */

• if (IS_ENABLED(CONFIG_EFI_CAPSULE_AUTHENTICATE) &&
  

•     !(image->image_capsule_support &
  

• 		CAPSULE_SUPPORT_AUTHENTICATION)) {
  

• 	/* no signature */
  

• 	ret = EFI_SECURITY_VIOLATION;
  

• 	goto out;
  

• }
  

• image_binary = (void *)image + sizeof(*image);

• vendor_code = image_binary + image->update_image_size;
  

• image_binary_size = image->update_image_size;
  

• vendor_code = image_binary + image_binary_size;
  

• if (!IS_ENABLED(CONFIG_EFI_CAPSULE_AUTHENTICATE) &&
  

•     (image->image_capsule_support &
  

• 		CAPSULE_SUPPORT_AUTHENTICATION)) {
  

• 	ret = efi_remove_auth_hdr(&image_binary,
  

• 				  &image_binary_size);
  

• 	if (ret != EFI_SUCCESS)
  

• 		goto out;
  

• }
  
  

  abort_reason = NULL; ret = EFI_CALL(fmp->set_image(fmp, image->update_image_index, image_binary,

• 			      image->update_image_size,
  

• 			      image_binary_size,
  		      vendor_code, NULL,
  		      &abort_reason));
  

  if (ret != EFI_SUCCESS) {

-- 2.31.0