[PATCH] objcopy: check input flavor before setting PE/COFF section alignment

Jan Beulich jbeulich@suse.com
Fri Apr 19 09:27:13 GMT 2024


coff_section_data() and elf_section_data() use the same underlying
field. The pointer being non-NULL therefore isn't sufficient to know
that pei_section_data() can validly be used on the incoming object.
Apparently in 64-bit-host builds the resulting memory corruption is
benign, whereas in 32-bit-host builds a segmentation fault occurs upon
de-referencing pei_section_data()'s return value.
---
Of course the value (first) being set on the input bfd is suspicious
in the first place: When copying e.g. ELF to PE/COFF, the option ought
to be similarly respected, yet clearly it can't be set like this then on
the incoming object. The change here is merely to address the testsuite
failures observed for Arm64 and RISC-V ("Check if efi app format is
recognized") as well as the (latent) memory corruption.

--- a/binutils/objcopy.c
+++ b/binutils/objcopy.c
@@ -4310,6 +4310,7 @@ setup_section (bfd *ibfd, sec_ptr isecti
   if (p != NULL)
     alignment = p->alignment;
   else if (pe_section_alignment != (bfd_vma) -1
+	   && bfd_get_flavour (ibfd) == bfd_target_coff_flavour
 	   && bfd_get_flavour (obfd) == bfd_target_coff_flavour)
     {
       alignment = power_of_two (pe_section_alignment);


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