From: Jan Janssen <medhefgo@web.de>
Date: Thu, 28 Sep 2023 14:22:13 +0000 (+0200)
Subject: elf2efi: Check ELF image base if possible
X-Git-Tag: v255-rc1~379^2~5
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5713c50d84296aa3d986f31fed04f970f93965d9;p=thirdparty%2Fsystemd.git

elf2efi: Check ELF image base if possible
---

diff --git a/tools/elf2efi.py b/tools/elf2efi.py
index f1fbf1e630f..8dbf881a0c5 100755
--- a/tools/elf2efi.py
+++ b/tools/elf2efi.py
@@ -348,7 +348,6 @@ def apply_elf_relative_relocation(
         addend = target.data[addend_offset : addend_offset + addend_size]
         addend = int.from_bytes(addend, byteorder="little")
 
-    # This currently assumes that the ELF file has an image base of 0.
     value = (image_base + addend).to_bytes(addend_size, byteorder="little")
     target.data[addend_offset : addend_offset + addend_size] = value
 
@@ -417,6 +416,13 @@ def convert_elf_relocations(
     if not flags_tag["d_val"] & ENUM_DT_FLAGS_1["DF_1_PIE"]:
         raise RuntimeError("ELF file is not a PIE.")
 
+    # This checks that the ELF image base is 0.
+    symtab = elf.get_section_by_name(".symtab")
+    if symtab:
+        exe_start = symtab.get_symbol_by_name("__executable_start")
+        if exe_start and exe_start[0]["st_value"] != 0:
+            raise RuntimeError("Unexpected ELF image base.")
+
     opt.SizeOfHeaders = align_to(
         PE_OFFSET
         + len(PE_MAGIC)