imagemagick: heap-based buffer overflow in .omp_outlined..32 (enhance.c)

["Agostino Sarubbo" <ago () gentoo org>]

Description:
imagemagick is a software suite to create, edit, compose, or convert bitmap images.

The complete ASan output of the issue:

# convert $FILE null
==109188==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x6020000049f8 at pc 0x7f81ecd9b4c2 bp 
0x7ffe3c52f850 sp 0x7ffe3c52f848
READ of size 8 at 0x6020000049f8 thread T0   
    #0 0x7f81ecd9b4c1 in .omp_outlined..32 
/var/tmp/portage/media-gfx/imagemagick-7.0.6.5/work/ImageMagick-7.0.6-5/MagickCore/enhance.c:1248:13  
    #1 0x7f81eb8395c2 in __kmp_invoke_microtask 
/var/tmp/portage/sys-libs/libomp-4.0.1/work/openmp-4.0.1.src/runtime/src/z_Linux_asm.s:1399 
    #2 0x7f81eb7e125a in __kmp_fork_call 
/var/tmp/portage/sys-libs/libomp-4.0.1/work/openmp-4.0.1.src/runtime/src/kmp_runtime.cpp:1858 
    #3 0x7f81eb7cd74f in __kmpc_fork_call 
/var/tmp/portage/sys-libs/libomp-4.0.1/work/openmp-4.0.1.src/runtime/src/kmp_csupport.cpp:337
    #4 0x7f81ecd999b9 in ContrastStretchImage 
/var/tmp/portage/media-gfx/imagemagick-7.0.6.5/work/ImageMagick-7.0.6-5/MagickCore/enhance.c:1213:11    
    #5 0x7f81ecbd2280 in SetImageType 
/var/tmp/portage/media-gfx/imagemagick-7.0.6.5/work/ImageMagick-7.0.6-5/MagickCore/attribute.c:1262:18
    #6 0x7f81e5acd5bd in WriteTIFFImage 
/var/tmp/portage/media-gfx/imagemagick-7.0.6.5/work/ImageMagick-7.0.6-5/coders/tiff.c:3245:16  
    #7 0x7f81eccc4026 in WriteImage 
/var/tmp/portage/media-gfx/imagemagick-7.0.6.5/work/ImageMagick-7.0.6-5/MagickCore/constitute.c:1114:14 
    #8 0x7f81eccc55a9 in WriteImages 
/var/tmp/portage/media-gfx/imagemagick-7.0.6.5/work/ImageMagick-7.0.6-5/MagickCore/constitute.c:1333:13
    #9 0x7f81ec50f456 in ConvertImageCommand 
/var/tmp/portage/media-gfx/imagemagick-7.0.6.5/work/ImageMagick-7.0.6-5/MagickWand/convert.c:3280:11
    #10 0x7f81ec62e225 in MagickCommandGenesis 
/var/tmp/portage/media-gfx/imagemagick-7.0.6.5/work/ImageMagick-7.0.6-5/MagickWand/mogrify.c:183:14    
    #11 0x5093e9 in MagickMain 
/var/tmp/portage/media-gfx/imagemagick-7.0.6.5/work/ImageMagick-7.0.6-5/utilities/magick.c:149:10  
    #12 0x5093e9 in main /var/tmp/portage/media-gfx/imagemagick-7.0.6.5/work/ImageMagick-7.0.6-5/utilities/magick.c:180 
    #13 0x7f81eb206680 in __libc_start_main 
/var/tmp/portage/sys-libs/glibc-2.23-r4/work/glibc-2.23/csu/../csu/libc-start.c:289   
    #14 0x41a1f8 in _init (/usr/bin/magick+0x41a1f8)   

0x6020000049f8 is located 0 bytes to the right of 8-byte region [0x6020000049f0,0x6020000049f8)
allocated by thread T0 here:  
    #0 0x4cfba8 in malloc 
/var/tmp/portage/sys-libs/compiler-rt-sanitizers-4.0.1/work/compiler-rt-4.0.1.src/lib/asan/asan_malloc_linux.cc:66
    #1 0x7f81ecef8df7 in AcquireMagickMemory 
/var/tmp/portage/media-gfx/imagemagick-7.0.6.5/work/ImageMagick-7.0.6-5/MagickCore/memory.c:464:10  
    #2 0x7f81ecef8df7 in AcquireQuantumMemory 
/var/tmp/portage/media-gfx/imagemagick-7.0.6.5/work/ImageMagick-7.0.6-5/MagickCore/memory.c:537    
    #3 0x7f81ecd97037 in ContrastStretchImage 
/var/tmp/portage/media-gfx/imagemagick-7.0.6.5/work/ImageMagick-7.0.6-5/MagickCore/enhance.c:1052:20    
    #4 0x7f81ecbd2280 in SetImageType 
/var/tmp/portage/media-gfx/imagemagick-7.0.6.5/work/ImageMagick-7.0.6-5/MagickCore/attribute.c:1262:18
    #5 0x7f81e5acd5bd in WriteTIFFImage 
/var/tmp/portage/media-gfx/imagemagick-7.0.6.5/work/ImageMagick-7.0.6-5/coders/tiff.c:3245:16
    #6 0x7f81eccc4026 in WriteImage 
/var/tmp/portage/media-gfx/imagemagick-7.0.6.5/work/ImageMagick-7.0.6-5/MagickCore/constitute.c:1114:14
    #7 0x7f81eccc55a9 in WriteImages 
/var/tmp/portage/media-gfx/imagemagick-7.0.6.5/work/ImageMagick-7.0.6-5/MagickCore/constitute.c:1333:13
    #8 0x7f81ec50f456 in ConvertImageCommand 
/var/tmp/portage/media-gfx/imagemagick-7.0.6.5/work/ImageMagick-7.0.6-5/MagickWand/convert.c:3280:11
    #9 0x7f81ec62e225 in MagickCommandGenesis 
/var/tmp/portage/media-gfx/imagemagick-7.0.6.5/work/ImageMagick-7.0.6-5/MagickWand/mogrify.c:183:14
    #10 0x5093e9 in MagickMain 
/var/tmp/portage/media-gfx/imagemagick-7.0.6.5/work/ImageMagick-7.0.6-5/utilities/magick.c:149:10
    #11 0x5093e9 in main /var/tmp/portage/media-gfx/imagemagick-7.0.6.5/work/ImageMagick-7.0.6-5/utilities/magick.c:180
    #12 0x7f81eb206680 in __libc_start_main 
/var/tmp/portage/sys-libs/glibc-2.23-r4/work/glibc-2.23/csu/../csu/libc-start.c:289

SUMMARY: AddressSanitizer: heap-buffer-overflow 
/var/tmp/portage/media-gfx/imagemagick-7.0.6.5/work/ImageMagick-7.0.6-5/MagickCore/enhance.c:1248:13 in 
.omp_outlined..32
Shadow bytes around the buggy address:
  0x0c047fff88e0: fa fa fd fd fa fa fd fd fa fa fd fd fa fa fd fd
  0x0c047fff88f0: fa fa fd fd fa fa fd fd fa fa fd fd fa fa fd fd
  0x0c047fff8900: fa fa fd fd fa fa fd fd fa fa fd fd fa fa fd fd
  0x0c047fff8910: fa fa fd fd fa fa fd fd fa fa fd fd fa fa fd fd
  0x0c047fff8920: fa fa 00 03 fa fa 00 04 fa fa 05 fa fa fa 00 00
=>0x0c047fff8930: fa fa 00 07 fa fa 00 04 fa fa 00 04 fa fa 00[fa]
  0x0c047fff8940: fa fa 00 fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff8950: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff8960: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff8970: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff8980: 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
==109188==ABORTING

Affected version:
7.0.6-5

Fixed version:
7.0.6-6 (not released atm)

Commit fix:
https://github.com/ImageMagick/ImageMagick/commit/1cc6f0ccc92c20c7cab6c4a7335daf29c91f0d8e

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

CVE:
CVE-2017-12876

Reproducer:
https://github.com/asarubbo/poc/blob/master/00306-imagemagick-heapoverflow-enhance_c

Timeline:
2017-08-09: bug discovered and reported to upstream
2017-08-10: blog post about the issue
2017-08-15: CVE assigned

Note:
This bug was found with American Fuzzy Lop.
This bug was identified with bare metal servers donated by Packet. This work is also supported by the Core 
Infrastructure Initiative.

Permalink:
https://blogs.gentoo.org/ago/2017/08/10/imagemagick-heap-based-buffer-overflow-in-omp_outlined-32-enhance-c/

--
Agostino Sarubbo
Gentoo Linux Developer