efi_loader: release file buffer after loading image

Commit 0e18f584de59 ("efi_loader: LoadImage: always allocate new pages")
ensured that whether we load an image from file or from memory we end up
with the same number of newly allocated buffers. But essentially we ended
up with one buffer too many in both cases:

efi_load_pe() copies and rebases the UEFI image.
We do not need the buffer with the file contents afterwards.

Fixes: 0e18f584de59 ("efi_loader: LoadImage: always allocate new pages")
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
index 4fc550d9f376fa657c0805d6c9977bebd583f512..7038246902efbe51625e17d1dc1d601c3fa15367 100644 (file)
--- a/lib/efi_loader/efi_boottime.c
+++ b/lib/efi_loader/efi_boottime.c
@@ -1691,6 +1691,7 @@ static efi_status_t EFIAPI efi_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;
 
        EFI_ENTRY("%d, %p, %pD, %p, %zd, %p", boot_policy, parent_image,
                  file_path, source_buffer, source_size, image_handle);
@@ -1706,7 +1707,7 @@ static efi_status_t EFIAPI efi_load_image(bool boot_policy,
        }
 
        if (!source_buffer) {
-               ret = efi_load_image_from_path(file_path, &source_buffer,
+               ret = efi_load_image_from_path(file_path, &dest_buffer,
                                               &source_size);
                if (ret != EFI_SUCCESS)
                        goto error;
@@ -1719,41 +1720,26 @@ static efi_status_t EFIAPI efi_load_image(bool boot_policy,
                /* In this case, file_path is the "device" path, i.e.
                 * something like a HARDWARE_DEVICE:MEMORY_MAPPED
                 */
-               u64 addr;
-               void *dest_buffer;
-
-               ret = efi_allocate_pages(EFI_ALLOCATE_ANY_PAGES,
-                                        EFI_RUNTIME_SERVICES_CODE,
-                                        efi_size_in_pages(source_size), &addr);
-               if (ret != EFI_SUCCESS)
-                       goto error;
-               dest_buffer = (void *)(uintptr_t)addr;
-               memcpy(dest_buffer, source_buffer, source_size);
-               source_buffer = dest_buffer;
-
+               dest_buffer = source_buffer;
                dp = file_path;
                fp = NULL;
        }
        ret = efi_setup_loaded_image(dp, fp, image_obj, &info);
-       if (ret != EFI_SUCCESS)
-               goto error_invalid_image;
-       ret = efi_load_pe(*image_obj, source_buffer, info);
-       if (ret != EFI_SUCCESS)
-               goto error_invalid_image;
-       /* Update the type of the allocated memory */
-       efi_add_memory_map((uintptr_t)source_buffer,
-                          efi_size_in_pages(source_size),
-                          info->image_code_type, false);
-       info->system_table = &systab;
-       info->parent_handle = parent_image;
-       return EFI_EXIT(EFI_SUCCESS);
-error_invalid_image:
-       /* The image is invalid. Release all associated resources. */
-       efi_free_pages((uintptr_t)source_buffer,
-                      efi_size_in_pages(source_size));
-       efi_delete_handle(*image_handle);
-       *image_handle = NULL;
-       free(info);
+       if (ret == EFI_SUCCESS)
+               ret = efi_load_pe(*image_obj, dest_buffer, info);
+       if (!source_buffer)
+               /* Release buffer to which file was loaded */
+               efi_free_pages((uintptr_t)dest_buffer,
+                              efi_size_in_pages(source_size));
+       if (ret == EFI_SUCCESS) {
+               info->system_table = &systab;
+               info->parent_handle = parent_image;
+       } else {
+               /* The image is invalid. Release all associated resources. */
+               efi_delete_handle(*image_handle);
+               *image_handle = NULL;
+               free(info);
+       }
 error:
        return EFI_EXIT(ret);
 }