CVE-2020-27796: Heap buffer overflow in PackLinuxElf32::invert_pt_dynamic · Issue #392 · upx/upx

==21202==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x62f00000c530 at pc 0x00000058b076 bp 0x7ffdc9ecf670 sp 0x7ffdc9ecf668
READ of size 4 at 0x62f00000c530 thread T0
    #0 0x58b075 in PackLinuxElf32::invert_pt_dynamic(N_Elf::Dyn<N_Elf::ElfITypes<LE16, LE32, LE32, LE32, LE32> > const*) /src/upx-multi/src/p_lx_elf.cpp:1676:25
    #1 0x588959 in PackLinuxElf32::PackLinuxElf32help1(InputFile*) /src/upx-multi/src/p_lx_elf.cpp:305:13
    #2 0x5d5e74 in PackLinuxElf32Le::PackLinuxElf32Le(InputFile*) /src/upx-multi/src/./p_lx_elf.h:395:9
    #3 0x5d5e74 in PackLinuxElf32x86::PackLinuxElf32x86(InputFile*) /src/upx-multi/src/p_lx_elf.cpp:4838:54
    #4 0x5d6261 in PackBSDElf32x86::PackBSDElf32x86(InputFile*) /src/upx-multi/src/p_lx_elf.cpp:4855:50
    #5 0x5d6261 in PackFreeBSDElf32x86::PackFreeBSDElf32x86(InputFile*) /src/upx-multi/src/p_lx_elf.cpp:4866:58
    #6 0x6e4460 in PackMaster::visitAllPackers(Packer* (*)(Packer*, void*), InputFile*, options_t const*, void*) /src/upx-multi/src/packmast.cpp:190:9
    #7 0x6e8ff1 in PackMaster::getUnpacker(InputFile*) /src/upx-multi/src/packmast.cpp:248:18
    #8 0x6e8ff1 in PackMaster::unpack(OutputFile*) /src/upx-multi/src/packmast.cpp:266:9
    #9 0x75826b in do_one_file(char const*, char*) /src/upx-multi/src/work.cpp:160:12
    #10 0x7597c2 in do_files(int, int, char**) /src/upx-multi/src/work.cpp:271:13
    #11 0x555aed in main /src/upx-multi/src/main.cpp:1538:5
    #12 0x7efe5d03d83f in __libc_start_main /build/glibc-e6zv40/glibc-2.23/csu/../csu/libc-start.c:291
    #13 0x41ce98 in _start (/out/upx-multi/upx-multi+0x41ce98)

0x62f00000c532 is located 0 bytes to the right of 49458-byte region [0x62f000000400,0x62f00000c532)
allocated by thread T0 here:
    #0 0x49519d in malloc (/out/upx-multi/upx-multi+0x49519d)
    #1 0x569797 in MemBuffer::alloc(unsigned long long) /src/upx-multi/src/mem.cpp:194:42

SUMMARY: AddressSanitizer: heap-buffer-overflow /src/upx-multi/src/p_lx_elf.cpp:1676:25 in PackLinuxElf32::invert_pt_dynamic(N_Elf::Dyn<N_Elf::ElfITypes<LE16, LE32, LE32, LE32, LE32> > const*)
Shadow bytes around the buggy address:
  0x0c5e7fff9850: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c5e7fff9860: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c5e7fff9870: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c5e7fff9880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c5e7fff9890: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x0c5e7fff98a0: 00 00 00 00 00 00[02]fa fa fa fa fa fa fa fa fa
  0x0c5e7fff98b0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c5e7fff98c0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c5e7fff98d0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c5e7fff98e0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c5e7fff98f0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
Shadow byte legend (one shadow byte represents 8 application bytes):
  Addressable:           00
  Partially addressable: 01 02 03 04 05 06 07
  Heap left redzone:       fa
  Freed heap region:       fd
  Stack left redzone:      f1
  Stack mid redzone:       f2
  Stack right redzone:     f3
  Stack after return:      f5
  Stack use after scope:   f8
  Global redzone:          f9
  Global init order:       f6
  Poisoned by user:        f7
  Container overflow:      fc
  Array cookie:            ac
  Intra object redzone:    bb
  ASan internal:           fe
  Left alloca redzone:     ca
  Right alloca redzone:    cb
  Shadow gap:              cc
==21202==ABORTING


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