Booting an EFI application directly from a raw block device creates
a device path without a file path node. efi_dp_split_file_path()
propagated this as a NULL file path, which was then exposed through
the Loaded Image Protocol.
The EDK2 shell dereferences LoadedImage->FilePath while looking
for startup.nsh and crashed barebox after the countdown.
Return an allocated empty device path for device-only images instead,
and make LoadImage() handle split failures explicitly.
Assisted-by: Codex:gpt-5.5
Fixes: ba9c4217b8ea ("efi: loader: boot: implement LoadImage BootService")
Signed-off-by: Ahmad Fatoum <[email protected]>
---
efi/loader/boot.c | 16 ++++++++++------
efi/loader/devicepath.c | 11 ++++++++++-
2 files changed, 20 insertions(+), 7 deletions(-)
diff --git a/efi/loader/boot.c b/efi/loader/boot.c
index adcfd96b4648..b92e6bb33093 100644
--- a/efi/loader/boot.c
+++ b/efi/loader/boot.c
@@ -1983,7 +1983,7 @@ efi_status_t EFIAPI efiloader_load_image(bool boot_policy,
struct efi_loaded_image_obj **image_obj =
(struct efi_loaded_image_obj **)image_handle;
efi_status_t ret;
- void *dest_buffer;
+ void *dest_buffer = NULL;
EFI_ENTRY("%d, %p, %pD, %p, %zu, %p", boot_policy, parent_image,
file_path, source_buffer, source_size, image_handle);
@@ -1996,6 +1996,7 @@ efi_status_t EFIAPI efiloader_load_image(bool boot_policy,
goto error;
}
+ *image_handle = NULL;
if (!source_buffer) {
ret = efi_load_image_from_path(boot_policy, file_path,
&dest_buffer, &source_size);
@@ -2005,10 +2006,13 @@ efi_status_t EFIAPI efiloader_load_image(bool
boot_policy,
dest_buffer = source_buffer;
}
/* split file_path which contains both the device and file parts */
- efi_dp_split_file_path(file_path, &dp, &fp);
- ret = efi_setup_loaded_image(dp, fp, image_obj, &info);
- if (ret == EFI_SUCCESS)
- ret = efi_load_pe(*image_obj, dest_buffer, source_size, info);
+ ret = efi_dp_split_file_path(file_path, &dp, &fp);
+ if (ret == EFI_SUCCESS) {
+ ret = efi_setup_loaded_image(dp, fp, image_obj, &info);
+ if (ret == EFI_SUCCESS)
+ ret = efi_load_pe(*image_obj, dest_buffer, source_size,
info);
+ }
+
if (!source_buffer)
/* Release buffer to which file was loaded */
efi_free_pages((uintptr_t)dest_buffer,
@@ -2016,7 +2020,7 @@ efi_status_t EFIAPI efiloader_load_image(bool boot_policy,
if (ret == EFI_SUCCESS || ret == EFI_SECURITY_VIOLATION) {
info->system_table = &systab;
info->parent_handle = parent_image;
- } else {
+ } else if (*image_handle) {
/* The image is invalid. Release all associated resources. */
efi_delete_handle(*image_handle);
*image_handle = NULL;
diff --git a/efi/loader/devicepath.c b/efi/loader/devicepath.c
index a12ab24caaa1..b181bf6993be 100644
--- a/efi/loader/devicepath.c
+++ b/efi/loader/devicepath.c
@@ -444,7 +444,8 @@ struct efi_device_path *efi_dp_append_node(const struct
efi_device_path *dp,
*
* @full_path: device path including device and file path
* @device_path: path of the device
- * @file_path: relative path of the file or NULL if there is none
+ * @file_path: relative path of the file or an empty device path if there
+ * is none
* Return: status code
*/
efi_status_t efi_dp_split_file_path(struct efi_device_path *full_path,
@@ -474,6 +475,14 @@ efi_status_t efi_dp_split_file_path(struct efi_device_path
*full_path,
p->length = sizeof(*p);
out:
+ if (!fp) {
+ fp = efi_dp_append_node(NULL, NULL);
+ if (!fp) {
+ free(dp);
+ return EFI_OUT_OF_RESOURCES;
+ }
+ }
+
*device_path = dp;
*file_path = fp;
return EFI_SUCCESS;
--
2.47.3
