Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-ID: <2803183.JXljhHXDl4@blackgate>
Date: Wed, 09 Nov 2016 15:42:22 +0100
From: Agostino Sarubbo <ago@...too.org>
To: oss-security@...ts.openwall.com
Cc: cve-assign@...re.org
Subject: libdwarf: heap-based buffer overflow in _dwarf_skim_forms (dwarf_macro5.c)

If it is suitable for a CVE please assign one. Thanks.

Description:
libdwarf is a library to consume and produce DWARF debug information.

A fuzz on an updated version revealed a buffer overflow.

The complete ASan output:

# dwarfdump $FILE
==2437==ERROR: AddressSanitizer: heap-buffer-overflow on address 
0x62000000fe5b at pc 0x000000462c7c bp 0x7ffea0d4b690 sp 0x7ffea0d4ae40
READ of size 29 at 0x62000000fe5b thread T0
    #0 0x462c7b in __interceptor_strlen /var/tmp/portage/sys-devel/llvm-3.8.1-
r2/work/llvm-3.8.1.src/projects/compiler-rt/lib/asan/asan_interceptors.cc:581
    #1 0x5edea2 in _dwarf_skim_forms 
/tmp/dwarf-20161021/libdwarf/dwarf_macro5.c:185:17
    #2 0x5edea2 in _dwarf_get_macro_ops_count_internal 
/tmp/dwarf-20161021/libdwarf/dwarf_macro5.c:346
    #3 0x5eb886 in _dwarf_internal_macro_context_by_offset 
/tmp/dwarf-20161021/libdwarf/dwarf_macro5.c:1338:11
    #4 0x5eb886 in _dwarf_internal_macro_context 
/tmp/dwarf-20161021/libdwarf/dwarf_macro5.c:1201
    #5 0x5ed10e in dwarf_get_macro_context_by_offset 
/tmp/dwarf-20161021/libdwarf/dwarf_macro5.c:1467:11
    #6 0x54f7be in print_macros_5style_this_cu 
/tmp/dwarf-20161021/dwarfdump/print_macro.c:288:16
    #7 0x514d0f in print_one_die_section 
/tmp/dwarf-20161021/dwarfdump/print_die.c:869:21
    #8 0x512262 in print_infos 
/tmp/dwarf-20161021/dwarfdump/print_die.c:371:16
    #9 0x4faafa in process_one_file 
/tmp/dwarf-20161021/dwarfdump/dwarfdump.c:1371:9
    #10 0x4faafa in main /tmp/dwarf-20161021/dwarfdump/dwarfdump.c:654
    #11 0x7f74b22e761f in __libc_start_main /var/tmp/portage/sys-
libs/glibc-2.22-r4/work/glibc-2.22/csu/libc-start.c:289
    #12 0x419588 in _start (/usr/bin/dwarfdump-asan+0x419588)

0x62000000fe5b is located 0 bytes to the right of 3547-byte region 
[0x62000000f080,0x62000000fe5b)
allocated by thread T0 here:
    #0 0x4c0ad8 in malloc /var/tmp/portage/sys-devel/llvm-3.8.1-
r2/work/llvm-3.8.1.src/projects/compiler-rt/lib/asan/asan_malloc_linux.cc:52
    #1 0x7f74b33c1206 in __libelf_set_rawdata_wrlock /tmp/portage/dev-
libs/elfutils-0.166/work/elfutils-0.166/libelf/elf_getdata.c:318

SUMMARY: AddressSanitizer: heap-buffer-overflow /var/tmp/portage/sys-
devel/llvm-3.8.1-r2/work/llvm-3.8.1.src/projects/compiler-
rt/lib/asan/asan_interceptors.cc:581 in __interceptor_strlen
Shadow bytes around the buggy address:
  0x0c407fff9f70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c407fff9f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c407fff9f90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c407fff9fa0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c407fff9fb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x0c407fff9fc0: 00 00 00 00 00 00 00 00 00 00 00[03]fa fa fa fa
  0x0c407fff9fd0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c407fff9fe0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c407fff9ff0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c407fffa000: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c407fffa010: 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
  Heap right redzone:      fb
  Freed heap region:       fd
  Stack left redzone:      f1
  Stack mid redzone:       f2
  Stack right redzone:     f3
  Stack partial redzone:   f4
  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
==2437==ABORTING

Affected version:
20161021

Fixed version:
N/A

Commit fix:
https://sourceforge.net/p/libdwarf/code/ci/583f8834083b5ef834c497f5b47797e16101a9a6/

Credit:
This bug was discovered by Agostino Sarubbo of Gentoo.

CVE:
N/A

Reproducer:
https://github.com/asarubbo/poc/blob/master/00027-libdwarf-heapoverflow-_dwarf_skim_forms

Timeline:
2016-11-02: bug discovered and reported to upstream
2016-11-05: upstream released a patch
2016-11-07: blog post about the issue

Note:
This bug was found with American Fuzzy Lop.

Permalink:
https://blogs.gentoo.org/ago/2016/11/07/libdwarf-heap-based-buffer-overflow-in-_dwarf_skim_forms-dwarf_macro5-c

Powered by blists - more mailing lists

Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.