out-of-bounds read in coders/xcf.c:373

[Moshe Kaplan]

This bug was found while fuzzing graphicsmagick with afl-fuzz

Tested on hg changeset 14720:3b1f1e0c1098

Command: gm convert %s /dev/null

=================================================================
==15344==ERROR: AddressSanitizer: heap-buffer-overflow on address 0xb4a00b05 at pc 0x89c00b1 bp 0xbfbdc838 sp 0xbfbdc830
READ of size 1 at 0xb4a00b05 thread T0
    #0 0x89c00b0 in load_tile /home/user/Desktop/graphicsmagick_fuzz_results/graphicsmagick/coders/xcf.c:373
    #1 0x89c00b0 in load_level /home/user/Desktop/graphicsmagick_fuzz_results/graphicsmagick/coders/xcf.c:810
    #2 0x89c00b0 in load_hierarchy /home/user/Desktop/graphicsmagick_fuzz_results/graphicsmagick/coders/xcf.c:977
    #3 0x89c00b0 in ReadOneLayer /home/user/Desktop/graphicsmagick_fuzz_results/graphicsmagick/coders/xcf.c:1137
    #4 0x89c00b0 in ReadXCFImage /home/user/Desktop/graphicsmagick_fuzz_results/graphicsmagick/coders/xcf.c:1589
    #5 0x8244d62 in ReadImage /home/user/Desktop/graphicsmagick_fuzz_results/graphicsmagick/magick/constitute.c:1607
    #6 0x812c3ac in ConvertImageCommand /home/user/Desktop/graphicsmagick_fuzz_results/graphicsmagick/magick/command.c:4348
    #7 0x8165066 in MagickCommand /home/user/Desktop/graphicsmagick_fuzz_results/graphicsmagick/magick/command.c:8862
    #8 0x81ed0dc in GMCommandSingle /home/user/Desktop/graphicsmagick_fuzz_results/graphicsmagick/magick/command.c:17338
    #9 0x81ea204 in GMCommand /home/user/Desktop/graphicsmagick_fuzz_results/graphicsmagick/magick/command.c:17391
    #10 0x80d4a76 in main /home/user/Desktop/graphicsmagick_fuzz_results/graphicsmagick/utilities/gm.c:61
    #11 0xb74c5a82 in __libc_start_main /build/buildd/eglibc-2.19/csu/libc-start.c:287
    #12 0x80d4904 in _start (/home/user/Desktop/graphicsmagick_fuzz_results/graphicsmagick/utilities/gm+0x80d4904)

0xb4a00b05 is located 0 bytes to the right of 21-byte region [0xb4a00af0,0xb4a00b05)
allocated by thread T0 here:
    #0 0x80bd531 in __interceptor_malloc (/home/user/Desktop/graphicsmagick_fuzz_results/graphicsmagick/utilities/gm+0x80bd531)
    #1 0x839bb38 in MagickMalloc /home/user/Desktop/graphicsmagick_fuzz_results/graphicsmagick/magick/memory.c:156
    #2 0x8244d62 in ReadImage /home/user/Desktop/graphicsmagick_fuzz_results/graphicsmagick/magick/constitute.c:1607
    #3 0x812c3ac in ConvertImageCommand /home/user/Desktop/graphicsmagick_fuzz_results/graphicsmagick/magick/command.c:4348
    #4 0x8165066 in MagickCommand /home/user/Desktop/graphicsmagick_fuzz_results/graphicsmagick/magick/command.c:8862
    #5 0x81ed0dc in GMCommandSingle /home/user/Desktop/graphicsmagick_fuzz_results/graphicsmagick/magick/command.c:17338
    #6 0x81ea204 in GMCommand /home/user/Desktop/graphicsmagick_fuzz_results/graphicsmagick/magick/command.c:17391
    #7 0x80d4a76 in main /home/user/Desktop/graphicsmagick_fuzz_results/graphicsmagick/utilities/gm.c:61

SUMMARY: AddressSanitizer: heap-buffer-overflow /home/user/Desktop/graphicsmagick_fuzz_results/graphicsmagick/coders/xcf.c:373 load_tile
Shadow bytes around the buggy address:
  0x36940110: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x36940120: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x36940130: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x36940140: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x36940150: fa fa fa fa fa fa fa fa fa fa fa fa fa fa 00 00
=>0x36940160:[05]fa fa fa fd fd fd fa fa fa fd fd fd fa fa fa
  0x36940170: fd fd fd fa fa fa fd fd fd fa fa fa 00 00 00 06
  0x36940180: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x36940190: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x369401a0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x369401b0: 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
  ASan internal: fe
==15344==ABORTING

[Moshe Kaplan (moshekaplan)]

input file to trigger crash

[Tyler Hicks (tyhicks)]

Thanks for fuzzing graphicsmagick and reporting this issue. Since graphicsmagick is in universe, it is community maintained. I also see that you fuzzed a branch of the upstream Mercurial tree. If you are able, I suggest coordinating directly with upstream GraphicsMagick. Once fixes are available, you may want to post a debdiff for this issue. When a debdiff is available, members of the security team will review it and publish the package. See the following link for more information: https://wiki.ubuntu.com/SecurityTeam/UpdateProcedures

[Bob Friesenhahn (bfriesen)]

This bug is present in all Ubuntu versions, is now fixed in upstream Mercurial, and the fix will be included in GraphicsMagick 1.3.24.

[Launchpad Janitor (janitor)]

[Expired for graphicsmagick (Ubuntu) because there has been no activity for 60 days.]