[PATCH v4 0/6] binfmt_elf: Support segments with 0 filesz and misaligned starts

[Kees Cook]

Hi,

This is the continuation of the work Eric started for handling
"p_memsz > p_filesz" in arbitrary segments (rather than just the last,
BSS, segment). I've added the suggested changes:

 - drop unused "elf_bss" variable
 - refactor load_elf_interp() to use elf_load()
 - refactor load_elf_library() to use elf_load()
 - report padzero() errors when PROT_WRITE is present
 - drop vm_brk()

Thanks!

-Kees

v4:
 - refactor load_elf_library() too
 - don't refactor padzero(), just test in the only remaining caller
 - drop now-unused vm_brk()
v3: https://lore.kernel.org/all/20230927033634.make.602-kees@xxxxxxxxxx
v2: https://lore.kernel.org/lkml/87sf71f123.fsf@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
v1: https://lore.kernel.org/lkml/87jzsemmsd.fsf_-_@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Eric W. Biederman (1):
  binfmt_elf: Support segments with 0 filesz and misaligned starts

Kees Cook (5):
  binfmt_elf: elf_bss no longer used by load_elf_binary()
  binfmt_elf: Use elf_load() for interpreter
  binfmt_elf: Use elf_load() for library
  binfmt_elf: Only report padzero() errors when PROT_WRITE
  mm: Remove unused vm_brk()

 fs/binfmt_elf.c    | 214 ++++++++++++++++-----------------------------
 include/linux/mm.h |   3 +-
 mm/mmap.c          |   6 --
 mm/nommu.c         |   5 --
 4 files changed, 76 insertions(+), 152 deletions(-)

-- 
2.34.1