Malformed input causes stack out of bounds read

• 報告者: hanno
• 担当者: arai
• チケットの種類: バグ
• 状況: 完了
• コンポーネント: (未割り当て)
• マイルストーン: (未割り当て)
• 優先度: 5 - 中
• 重要度: 5 - 中
• 解決法: なし
• ファイル: なし

詳細 返信

A malformed input file can cause an out of bounds read in lha (current git code). Here's a sample file (unfortunately no attachments possible in this bugtracker): https://crashes.fuzzing-project.org/lha-oob-stack-read-get_extended_header.lha

To see this one must compile lha with address sanitizer enabled (-fsanitize=address in CFLAGS). Test with ./lha l input_file

This was found with the help of american fuzzy lop.

The output from Address Sanitizer:

==27182==ERROR: AddressSanitizer: stack-buffer-underflow on address 0x7ffe0811d5bf at pc 0x0000004fddfc bp 0x7ffe0811d590 sp 0x7ffe0811d588
READ of size 1 at 0x7ffe0811d5bf thread T0
    #0 0x4fddfb in get_word /f/lha/lha/src/header.c:115:10
    #1 0x4fddfb in get_extended_header /f/lha/lha/src/header.c:705
    #2 0x4eb897 in get_header_level2 /f/lha/lha/src/header.c:1048:19
    #3 0x4eb897 in get_header /f/lha/lha/src/header.c:1182
    #4 0x51af30 in cmd_list /f/lha/lha/src/lhlist.c:337:12
    #5 0x50ebcb in main /f/lha/lha/src/lharc.c:686:9
    #6 0x7f2f775b27af in __libc_start_main (/lib64/libc.so.6+0x207af)
    #7 0x418aa8 in _start (/mnt/ram/lha/lha+0x418aa8)

Address 0x7ffe0811d5bf is located in stack of thread T0 at offset 31 in frame
    #0 0x4fa01f in get_extended_header /f/lha/lha/src/header.c:538

  This frame has 2 object(s):
    [32, 4128) 'data' <== Memory access at offset 31 underflows this variable
    [4256, 5280) 'dirname'
HINT: this may be a false positive if your program uses some custom stack unwind mechanism or swapcontext
      (longjmp and C++ exceptions *are* supported)
SUMMARY: AddressSanitizer: stack-buffer-underflow /f/lha/lha/src/header.c:115:10 in get_word
Shadow bytes around the buggy address:
  0x10004101ba60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x10004101ba70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x10004101ba80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x10004101ba90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x10004101baa0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x10004101bab0: 00 00 00 00 f1 f1 f1[f1]00 00 00 00 00 00 00 00
  0x10004101bac0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x10004101bad0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x10004101bae0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x10004101baf0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x10004101bb00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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
==27182==ABORTING

チケットの履歴 (3 件中 3 件表示)

2016-01-18 23:33 更新者: hanno

• 新しいチケット "Malformed input causes stack out of bounds read" が作成されました

2016-01-19 06:14 更新者: arai

• 担当者 が (未割り当て) から arai に更新されました

2016-01-23 12:42 更新者: arai

• チケット完了時刻 が 2016-01-23 12:42 に更新されました
• 状況 が オープン から 完了 に更新されました

コメント 返信

Fixed at 2f6c23d

Thanks for your report.