From: Heinrich Schuchardt <xypron.glpk@gmx.de>
Date: Wed, 6 Feb 2019 18:41:29 +0000 (+0100)
Subject: efi_loader: error handling in efi_setup_loaded_image()
X-Git-Tag: v2019.04-rc2~6^2~7
X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=16112f9f4832761e6af6f5ddb74c77a107992cb7;p=oweals%2Fu-boot.git

efi_loader: error handling in efi_setup_loaded_image()

In case of an error we should set the returned pointers to NULL. This
ensures that an illegal free does not occur even if the caller calls
free() for the handles.

If protocols cannot be installed, release all resources.

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 f74f989e0a..d69160a6c2 100644
--- a/lib/efi_loader/efi_boottime.c
+++ b/lib/efi_loader/efi_boottime.c
@@ -1497,15 +1497,18 @@ static efi_status_t EFIAPI efi_install_configuration_table_ext(efi_guid_t *guid,
 
 /**
  * efi_setup_loaded_image() - initialize a loaded image
- * @info:        loaded image info to be passed to the entry point of the image
- * @obj:         internal object associated with the loaded image
- * @device_path: device path of the loaded image
- * @file_path:   file path of the loaded image
  *
  * Initialize a loaded_image_info and loaded_image_info object with correct
  * protocols, boot-device, etc.
  *
- * Return: status code
+ * In case of an error *handle_ptr and *info_ptr are set to NULL and an error
+ * code is returned.
+ *
+ * @device_path:	device path of the loaded image
+ * @file_path:		file path of the loaded image
+ * @handle_ptr:		handle of the loaded image
+ * @info_ptr:		loaded image protocol
+ * Return:		status code
  */
 efi_status_t efi_setup_loaded_image(struct efi_device_path *device_path,
 				    struct efi_device_path *file_path,
@@ -1513,8 +1516,12 @@ efi_status_t efi_setup_loaded_image(struct efi_device_path *device_path,
 				    struct efi_loaded_image **info_ptr)
 {
 	efi_status_t ret;
-	struct efi_loaded_image *info;
-	struct efi_loaded_image_obj *obj;
+	struct efi_loaded_image *info = NULL;
+	struct efi_loaded_image_obj *obj = NULL;
+
+	/* In case of EFI_OUT_OF_RESOURCES avoid illegal free by caller. */
+	*handle_ptr = NULL;
+	*info_ptr = NULL;
 
 	info = calloc(1, sizeof(*info));
 	if (!info)
@@ -1528,11 +1535,6 @@ efi_status_t efi_setup_loaded_image(struct efi_device_path *device_path,
 	/* Add internal object to object list */
 	efi_add_handle(&obj->header);
 
-	if (info_ptr)
-		*info_ptr = info;
-	if (handle_ptr)
-		*handle_ptr = obj;
-
 	info->revision =  EFI_LOADED_IMAGE_PROTOCOL_REVISION;
 	info->file_path = file_path;
 	info->system_table = &systab;
@@ -1578,9 +1580,16 @@ efi_status_t efi_setup_loaded_image(struct efi_device_path *device_path,
 		goto failure;
 #endif
 
+	if (info_ptr)
+		*info_ptr = info;
+	if (handle_ptr)
+		*handle_ptr = obj;
+
 	return ret;
 failure:
 	printf("ERROR: Failure to install protocols for loaded image\n");
+	efi_delete_handle(&obj->header);
+	free(info);
 	return ret;
 }