out-of-bounds read in coders/pcx.c:536

[Moshe Kaplan]

This bug was found while fuzzing ImageMagick with afl-fuzz

Tested on ImageMagick git commit %s

Command: magick id:000169,sig:06,src:000734+004696,op:splice,rep:128 /dev/null

=================================================================
==32731==ERROR: AddressSanitizer: heap-buffer-overflow on address 0xb3503080 at pc 0x8652c1c bp 0xbfc261a8 sp 0xbfc261a0
READ of size 1 at 0xb3503080 thread T0
    #0 0x8652c1b in ReadPCXImage /home/user/Desktop/imagemagick_fuzz_results/ImageMagick/coders/pcx.c:536
    #1 0x8a8ad6a in ReadImage /home/user/Desktop/imagemagick_fuzz_results/ImageMagick/MagickCore/constitute.c:494
    #2 0x8a92bdf in ReadImages /home/user/Desktop/imagemagick_fuzz_results/ImageMagick/MagickCore/constitute.c:844
    #3 0x9375c09 in CLINoImageOperator /home/user/Desktop/imagemagick_fuzz_results/ImageMagick/MagickWand/operation.c:4685
    #4 0x937e0f1 in CLIOption /home/user/Desktop/imagemagick_fuzz_results/ImageMagick/MagickWand/operation.c:5179
    #5 0x910ae9d in ProcessCommandOptions /home/user/Desktop/imagemagick_fuzz_results/ImageMagick/MagickWand/magick-cli.c:474
    #6 0x910e215 in MagickImageCommand /home/user/Desktop/imagemagick_fuzz_results/ImageMagick/MagickWand/magick-cli.c:786
    #7 0x91126f9 in MagickCommandGenesis /home/user/Desktop/imagemagick_fuzz_results/ImageMagick/MagickWand/mogrify.c:172
    #8 0x80de16d in MagickMain /home/user/Desktop/imagemagick_fuzz_results/ImageMagick/utilities/magick.c:74
    #9 0x80de16d in main /home/user/Desktop/imagemagick_fuzz_results/ImageMagick/utilities/magick.c:85
    #10 0xb7477a82 in __libc_start_main /build/buildd/eglibc-2.19/csu/libc-start.c:287
    #11 0x80ddf94 in _start (/usr/local/bin/magick+0x80ddf94)

0xb3503080 is located 0 bytes to the right of 2048-byte region [0xb3502880,0xb3503080)
allocated by thread T0 here:
    #0 0x80c7061 in __interceptor_posix_memalign (/usr/local/bin/magick+0x80c7061)
    #1 0x8189123 in AcquireAlignedMemory /home/user/Desktop/imagemagick_fuzz_results/ImageMagick/MagickCore/memory.c:273
    #2 0x8189123 in AcquireVirtualMemory /home/user/Desktop/imagemagick_fuzz_results/ImageMagick/MagickCore/memory.c:597
    #3 0x864a867 in ReadPCXImage /home/user/Desktop/imagemagick_fuzz_results/ImageMagick/coders/pcx.c:394
    #4 0x8a8ad6a in ReadImage /home/user/Desktop/imagemagick_fuzz_results/ImageMagick/MagickCore/constitute.c:494
    #5 0x8a92bdf in ReadImages /home/user/Desktop/imagemagick_fuzz_results/ImageMagick/MagickCore/constitute.c:844
    #6 0x9375c09 in CLINoImageOperator /home/user/Desktop/imagemagick_fuzz_results/ImageMagick/MagickWand/operation.c:4685
    #7 0x937e0f1 in CLIOption /home/user/Desktop/imagemagick_fuzz_results/ImageMagick/MagickWand/operation.c:5179
    #8 0x910ae9d in ProcessCommandOptions /home/user/Desktop/imagemagick_fuzz_results/ImageMagick/MagickWand/magick-cli.c:474

SUMMARY: AddressSanitizer: heap-buffer-overflow /home/user/Desktop/imagemagick_fuzz_results/ImageMagick/coders/pcx.c:536 ReadPCXImage
Shadow bytes around the buggy address:
  0x366a05c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x366a05d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x366a05e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x366a05f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x366a0600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x366a0610:[fa]fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x366a0620: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x366a0630: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x366a0640: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x366a0650: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
  0x366a0660: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd
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
  ASan internal: fe
==32731==ABORTING

[Moshe Kaplan (moshekaplan)]

input file to trigger crash

[Moshe Kaplan (moshekaplan)]

Reported upstream at: https://github.com/ImageMagick/ImageMagick/issues/118