efi_loader: parameter checks in StartImage and Exit()
Add parameter checks in the StartImage() and Exit() boottime services:
- check that the image handle is valid and has the loaded image protocol
installed
- in StartImage() record the current image
- in Exit() check that the image is the current image
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 6aac839..970c016 100644
--- a/lib/efi_loader/efi_boottime.c
+++ b/lib/efi_loader/efi_boottime.c
@@ -26,6 +26,9 @@
/* List of all events */
LIST_HEAD(efi_events);
+/* Handle of the currently executing image */
+static efi_handle_t current_image;
+
/*
* If we're running on nasty systems (32bit ARM booting into non-EFI Linux)
* we need to do trickery with caches. Since we don't want to break the EFI
@@ -2631,9 +2634,18 @@
struct efi_loaded_image_obj *image_obj =
(struct efi_loaded_image_obj *)image_handle;
efi_status_t ret;
+ void *info;
+ efi_handle_t parent_image = current_image;
EFI_ENTRY("%p, %p, %p", image_handle, exit_data_size, exit_data);
+ /* Check parameters */
+ ret = EFI_CALL(efi_open_protocol(image_handle, &efi_guid_loaded_image,
+ &info, NULL, NULL,
+ EFI_OPEN_PROTOCOL_GET_PROTOCOL));
+ if (ret != EFI_SUCCESS)
+ return EFI_EXIT(EFI_INVALID_PARAMETER);
+
efi_is_direct_boot = false;
/* call the image! */
@@ -2662,9 +2674,11 @@
__efi_nesting_dec(),
(unsigned long)((uintptr_t)image_obj->exit_status &
~EFI_ERROR_MASK));
+ current_image = parent_image;
return EFI_EXIT(image_obj->exit_status);
}
+ current_image = image_handle;
ret = EFI_CALL(image_obj->entry(image_handle, &systab));
/*
@@ -2699,12 +2713,23 @@
* TODO: We should call the unload procedure of the loaded
* image protocol.
*/
+ efi_status_t ret;
+ void *info;
struct efi_loaded_image_obj *image_obj =
(struct efi_loaded_image_obj *)image_handle;
EFI_ENTRY("%p, %ld, %zu, %p", image_handle, exit_status,
exit_data_size, exit_data);
+ /* Check parameters */
+ if (image_handle != current_image)
+ goto out;
+ ret = EFI_CALL(efi_open_protocol(image_handle, &efi_guid_loaded_image,
+ &info, NULL, NULL,
+ EFI_OPEN_PROTOCOL_GET_PROTOCOL));
+ if (ret != EFI_SUCCESS)
+ goto out;
+
/* Make sure entry/exit counts for EFI world cross-overs match */
EFI_EXIT(exit_status);
@@ -2718,6 +2743,8 @@
longjmp(&image_obj->exit_jmp, 1);
panic("EFI application exited");
+out:
+ return EFI_EXIT(EFI_INVALID_PARAMETER);
}
/**