gnu/packages/patches/upx-fix-CVE-2017-15056.patch

   1 From 3e0c2966dffb5dadb512a476ef4be3d0cc51c2be Mon Sep 17 00:00:00 2001
   2 From: Pierre Neidhardt <ambrevar@gmail.com>
   3 Date: Sat, 16 Jun 2018 16:35:00 +0200
   4 Subject: [PATCH] Protect against bad crafted input
   5
   6 Also check for wrap-around when checking oversize involving e_shoff and e_shnum.
   7
   8 raised by https://github.com/upx/upx/pull/190
   9         modified:   p_lx_elf.cpp
  10 ---
  11  src/p_lx_elf.cpp | 30 ++++++++++++++++++++++++++++++
  12  1 file changed, 30 insertions(+)
  13
  14 diff --git a/src/p_lx_elf.cpp b/src/p_lx_elf.cpp
  15 index 822a7652..41e805ee 100644
  16 --- a/src/p_lx_elf.cpp
  17 +++ b/src/p_lx_elf.cpp
  18 @@ -235,8 +235,17 @@ PackLinuxElf32::PackLinuxElf32help1(InputFile *f)
  19          sz_phdrs = 0;
  20          return;
  21      }
  22 +    if (0==e_phnum) throwCantUnpack("0==e_phnum");
  23      e_phoff = get_te32(&ehdri.e_phoff);
  24 +    unsigned const last_Phdr = e_phoff + e_phnum * sizeof(Elf32_Phdr);
  25 +    if (last_Phdr < e_phoff || (unsigned long)file_size < last_Phdr) {
  26 +        throwCantUnpack("bad e_phoff");
  27 +    }
  28      e_shoff = get_te32(&ehdri.e_shoff);
  29 +    unsigned const last_Shdr = e_shoff + e_shnum * sizeof(Elf32_Shdr);
  30 +    if (last_Shdr < e_shoff || (unsigned long)file_size < last_Shdr) {
  31 +        throwCantUnpack("bad e_shoff");
  32 +    }
  33      sz_phdrs = e_phnum * e_phentsize;
  34
  35      if (f && Elf32_Ehdr::ET_DYN!=e_type) {
  36 @@ -599,8 +608,17 @@ PackLinuxElf64::PackLinuxElf64help1(InputFile *f)
  37          sz_phdrs = 0;
  38          return;
  39      }
  40 +    if (0==e_phnum) throwCantUnpack("0==e_phnum");
  41      e_phoff = get_te64(&ehdri.e_phoff);
  42 +    upx_uint64_t const last_Phdr = e_phoff + e_phnum * sizeof(Elf64_Phdr);
  43 +    if (last_Phdr < e_phoff || (unsigned long)file_size < last_Phdr) {
  44 +        throwCantUnpack("bad e_phoff");
  45 +    }
  46      e_shoff = get_te64(&ehdri.e_shoff);
  47 +    upx_uint64_t const last_Shdr = e_shoff + e_shnum * sizeof(Elf64_Shdr);
  48 +    if (last_Shdr < e_shoff || (unsigned long)file_size < last_Shdr) {
  49 +        throwCantUnpack("bad e_shoff");
  50 +    }
  51      sz_phdrs = e_phnum * e_phentsize;
  52
  53      if (f && Elf64_Ehdr::ET_DYN!=e_type) {
  54 @@ -3763,6 +3781,9 @@ void PackLinuxElf64::pack4(OutputFile *fo, Filter &ft)
  55
  56  void PackLinuxElf64::unpack(OutputFile *fo)
  57  {
  58 +    if (e_phoff != sizeof(Elf64_Ehdr)) {// Phdrs not contiguous with Ehdr
  59 +        throwCantUnpack("bad e_phoff");
  60 +    }
  61      unsigned const c_phnum = get_te16(&ehdri.e_phnum);
  62      upx_uint64_t old_data_off = 0;
  63      upx_uint64_t old_data_len = 0;
  64 @@ -3828,6 +3849,9 @@ void PackLinuxElf64::unpack(OutputFile *fo)
  65      unsigned total_out = 0;
  66      unsigned c_adler = upx_adler32(NULL, 0);
  67      unsigned u_adler = upx_adler32(NULL, 0);
  68 +    if ((MAX_ELF_HDR - sizeof(Elf64_Ehdr))/sizeof(Elf64_Phdr) < u_phnum) {
  69 +        throwCantUnpack("bad compressed e_phnum");
  70 +    }
  71
  72      // Packed ET_EXE has no PT_DYNAMIC.
  73      // Packed ET_DYN has original PT_DYNAMIC for info needed by rtld.
  74 @@ -4383,6 +4407,9 @@ Elf64_Sym const *PackLinuxElf64::elf_lookup(char const *name) const
  75
  76  void PackLinuxElf32::unpack(OutputFile *fo)
  77  {
  78 +    if (e_phoff != sizeof(Elf32_Ehdr)) {// Phdrs not contiguous with Ehdr
  79 +        throwCantUnpack("bad e_phoff");
  80 +    }
  81      unsigned const c_phnum = get_te16(&ehdri.e_phnum);
  82      unsigned old_data_off = 0;
  83      unsigned old_data_len = 0;
  84 @@ -4449,6 +4476,9 @@ void PackLinuxElf32::unpack(OutputFile *fo)
  85      unsigned total_out = 0;
  86      unsigned c_adler = upx_adler32(NULL, 0);
  87      unsigned u_adler = upx_adler32(NULL, 0);
  88 +    if ((MAX_ELF_HDR - sizeof(Elf32_Ehdr))/sizeof(Elf32_Phdr) < u_phnum) {
  89 +        throwCantUnpack("bad compressed e_phnum");
  90 +    }
  91
  92      // Packed ET_EXE has no PT_DYNAMIC.
  93      // Packed ET_DYN has original PT_DYNAMIC for info needed by rtld.
  94 --
  95 2.17.0
  96