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FreeType 2.5.3 OpenType parsing heap-based out-of-bounds read in "tt_sbit_decoder_load_image" #196

Closed GoogleCodeExporter closed 9 years ago

GoogleCodeExporter commented 9 years ago 
The following heap-based out-of-bounds memory read has been encountered in 
FreeType while fuzzing OpenType fonts. It has been reproduced with the current 
version of freetype2 from master git branch, with a 64-bit build of the ftbench 
utility compiled with AddressSanitizer:

$ ftbench <file>

Attached is a POC file which triggers the condition.

=================================================================
==12771==ERROR: AddressSanitizer: heap-buffer-overflow on address 
0x60800000bf76 at pc 0x8ccd60 bp 0x7fff465de830 sp 0x7fff465de828
READ of size 1 at 0x60800000bf76 thread T0
    #0 0x8ccd5f in tt_sbit_decoder_load_image freetype2/src/sfnt/ttsbit.c:1178
    #1 0x8b7f2d in tt_face_load_sbit_image freetype2/src/sfnt/ttsbit.c:1412
    #2 0x6d6c3a in cff_slot_load freetype2/src/cff/cffgload.c:2670
    #3 0x69dbcc in cff_glyph_load freetype2/src/cff/cffdrivr.c:185
    #4 0x4a427e in FT_Load_Glyph freetype2/src/base/ftobjs.c:726
    #5 0x491d69 in test_load ft2demos-2.5.3/src/ftbench.c:249
    #6 0x492b51 in benchmark ft2demos-2.5.3/src/ftbench.c:216
    #7 0x48e962 in main ft2demos-2.5.3/src/ftbench.c:1020

0x60800000bf76 is located 2 bytes to the right of 84-byte region 
[0x60800000bf20,0x60800000bf74)
allocated by thread T0 here:
    #0 0x472081 in __interceptor_malloc (ft2demos-2.5.3/bin/ftbench+0x472081)
    #1 0xaf3a2f in ft_alloc freetype2/src/base/ftsystem.c:74
    #2 0x526b21 in ft_mem_qalloc freetype2/src/base/ftutil.c:76
    #3 0x525591 in FT_Stream_EnterFrame freetype2/src/base/ftstream.c:267
    #4 0x524d51 in FT_Stream_ExtractFrame freetype2/src/base/ftstream.c:200
    #5 0x8c01f1 in tt_face_load_sbit freetype2/src/sfnt/ttsbit.c:97
    #6 0x8a44b2 in sfnt_load_face freetype2/src/sfnt/sfobjs.c:1142
    #7 0x691bce in cff_face_init freetype2/src/cff/cffobjs.c:543
    #8 0x4cc13e in open_face freetype2/src/base/ftobjs.c:1191
    #9 0x4c794b in FT_Open_Face freetype2/src/base/ftobjs.c:2123
    #10 0x4c5b58 in FT_New_Face freetype2/src/base/ftobjs.c:1254
    #11 0x491533 in get_face ft2demos-2.5.3/src/ftbench.c:705
    #12 0x48d748 in main ft2demos-2.5.3/src/ftbench.c:924

SUMMARY: AddressSanitizer: heap-buffer-overflow 
freetype2/src/sfnt/ttsbit.c:1178 tt_sbit_decoder_load_image
Shadow bytes around the buggy address:
  0x0c107fff9790: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c107fff97a0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c107fff97b0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c107fff97c0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c107fff97d0: fa fa fa fa 00 00 00 00 00 00 00 00 00 00 00 00
=>0x0c107fff97e0: fa fa fa fa 00 00 00 00 00 00 00 00 00 00[04]fa
  0x0c107fff97f0: fa fa fa fa 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c107fff9800: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c107fff9810: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c107fff9820: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c107fff9830: 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
  Contiguous container OOB:fc
  ASan internal:           fe
==12771==ABORTING

Original issue reported on code.google.com by mjurc...@google.com on 24 Nov 2014 at 8:28

Attachments:

GoogleCodeExporter commented 9 years ago 
Reported in https://savannah.nongnu.org/bugs/?43680.

Original comment by mjurc...@google.com on 24 Nov 2014 at 8:29

GoogleCodeExporter commented 9 years ago 
Fixed in 
http://git.savannah.gnu.org/cgit/freetype/freetype2.git/commit/?id=f0292bb9920aa
1dbfed5f53861e7c7a89b35833a.

Original comment by mjurc...@google.com on 24 Nov 2014 at 10:00

GoogleCodeExporter commented 9 years ago 
All fixed by upstream:

FreeType 2.5.5

2014-12-30
FreeType 2.5.5 has been released. This is a minor bug fix release: All users of 
PCF fonts should update, since version 2.5.4 introduced a bug that prevented 
reading of such font files if not compressed.

FreeType 2.5.4

2014-12-06
FreeType 2.5.4 has been released. All users should upgrade due to another fix 
for vulnerability CVE-2014-2240 in the CFF driver. The library also contains a 
new round of patches for better protection against malformed fonts.

The main new feature, which is also one of the targets mentioned in the pledgie 
roadmap below, is auto-hinting support for Devanagari and Telugu, two widely 
used Indic scripts. A more detailed description of the remaining changes and 
fixes can be found here.

Original comment by cev...@google.com on 26 Jan 2015 at 5:27

GoogleCodeExporter commented 9 years ago

Original comment by mjurc...@google.com on 25 Feb 2015 at 1:55