From 23428bb19e49cf510c65e2896f1a7e4b12ca1dbc Mon Sep 17 00:00:00 2001 From: Daan De Meyer Date: Mon, 27 Mar 2023 13:41:59 +0200 Subject: [PATCH] ukify: Weaken file alignment assertions Older versions of the stub are not aligned to the PE file alignment size. If we remove the assertions, the UKI still boots without issues, so let's drop the assertions and print a message about it instead. --- src/ukify/ukify.py | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/src/ukify/ukify.py b/src/ukify/ukify.py index 2cdfc01ad4f..99128014d93 100755 --- a/src/ukify/ukify.py +++ b/src/ukify/ukify.py @@ -449,7 +449,7 @@ class PeError(Exception): def pe_add_sections(uki: UKI, output: str): pe = pefile.PE(uki.executable, fast_load=True) - assert len(pe.__data__) % pe.OPTIONAL_HEADER.FileAlignment == 0 + assert pe.FILE_HEADER.PointerToSymbolTable != 0 or len(pe.__data__) % pe.OPTIONAL_HEADER.FileAlignment == 0 warnings = pe.get_warnings() if warnings: @@ -460,6 +460,12 @@ def pe_add_sections(uki: UKI, output: str): # We could strip the signatures, but why would anyone sign the stub? raise PeError(f'Stub image is signed, refusing.') + # If the executable has not been stripped, it might not be aligned to a multiple of the file alignment so + # let's make sure it is by padding it. + if pe.FILE_HEADER.PointerToSymbolTable != 0: + padlen = round_up(len(pe.__data__), pe.OPTIONAL_HEADER.FileAlignment) - len(pe.__data__) + pe.__data__ = pe.__data__[:] + padlen * b'\0' + for section in uki.sections: new_section = pefile.SectionStructure(pe.__IMAGE_SECTION_HEADER_format__, pe=pe) new_section.__unpack__(b'\0' * new_section.sizeof()) -- 2.47.3