efi_loader: check parameters of GetMemoryMap

Check the parameters of boottime service GetMemoryMap().
Return EFI_INVALID_PARAMETER where required by the UEFI spec.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>

lib/efi_loader/efi_memory.c

@@ -453,6 +453,9 @@ efi_status_t efi_get_memory_map(efi_uintn_t *memory_map_size,
 	struct list_head *lhandle;
 	efi_uintn_t provided_map_size = *memory_map_size;
 
+	if (!memory_map_size)
+		return EFI_INVALID_PARAMETER;
+
 	list_for_each(lhandle, &efi_mem)
 		map_entries++;
 
@@ -463,6 +466,9 @@ efi_status_t efi_get_memory_map(efi_uintn_t *memory_map_size,
 	if (provided_map_size < map_size)
 		return EFI_BUFFER_TOO_SMALL;
 
+	if (!memory_map)
+		return EFI_INVALID_PARAMETER;
+
 	if (descriptor_size)
 		*descriptor_size = sizeof(struct efi_mem_desc);
 
@@ -470,7 +476,6 @@ efi_status_t efi_get_memory_map(efi_uintn_t *memory_map_size,
 		*descriptor_version = EFI_MEMORY_DESCRIPTOR_VERSION;
 
 	/* Copy list into array */
-	if (memory_map) {
 	/* Return the list in ascending order */
 	memory_map = &memory_map[map_entries - 1];
 	list_for_each(lhandle, &efi_mem) {
@@ -480,8 +485,8 @@ efi_status_t efi_get_memory_map(efi_uintn_t *memory_map_size,
 		*memory_map = lmem->desc;
 		memory_map--;
 	}
-	}
 
+	if (map_key)
 		*map_key = 0;
 
 	return EFI_SUCCESS;