#361 out-of-bounds read in coders/xpm.c:150:24

[moshe]

This bug was found while fuzzing graphicsmagick with afl-fuzz

Tested on hg changeset 44ed8318ba6a+

Command: gm convert id:000024,sig:06,src:000336,op:flip2,pos:72 /dev/null

=================================================================
==16678==ERROR: AddressSanitizer: heap-buffer-overflow on address 0xb3e20685 at pc 0x0856dfd7 bp 0xbffe6a58 sp 0xbffe6a50
READ of size 1 at 0xb3e20685 thread T0
#0 0x856dfd6 in ParseColor /home/user/Desktop/graphicsmagick/coders/xpm.c:150:24
#1 0x856dfd6 in ReadXPMImage /home/user/Desktop/graphicsmagick/coders/xpm.c:358
#2 0x81f84b4 in ReadImage /home/user/Desktop/graphicsmagick/magick/constitute.c:1607:14
#3 0x816fbca in ConvertImageCommand /home/user/Desktop/graphicsmagick/magick/command.c:4348:22
#4 0x8187f6b in MagickCommand /home/user/Desktop/graphicsmagick/magick/command.c:8862:27
#5 0x81cd999 in GMCommandSingle /home/user/Desktop/graphicsmagick/magick/command.c:17338:10
#6 0x81cc6ae in GMCommand /home/user/Desktop/graphicsmagick/magick/command.c:17391:16
#7 0x8139511 in main /home/user/Desktop/graphicsmagick/utilities/gm.c:61:10
#8 0xb74ed73d in __libc_start_main /build/glibc-tVsQx_/glibc-2.21/csu/libc-start.c:289
#9 0x807fd9b in _start (/home/user/Desktop/graphicsmagick/utilities/gm+0x807fd9b)

0xb3e20685 is located 0 bytes to the right of 2053-byte region [0xb3e1fe80,0xb3e20685)
allocated by thread T0 here:
#0 0x8117a29 in malloc (/home/user/Desktop/graphicsmagick/utilities/gm+0x8117a29)
#1 0x827e984 in MagickMalloc /home/user/Desktop/graphicsmagick/magick/memory.c:156:11
#2 0x856a8ec in ReadXPMImage /home/user/Desktop/graphicsmagick/coders/xpm.c:317:12
#3 0x81f84b4 in ReadImage /home/user/Desktop/graphicsmagick/magick/constitute.c:1607:14
#4 0x816fbca in ConvertImageCommand /home/user/Desktop/graphicsmagick/magick/command.c:4348:22
#5 0x8187f6b in MagickCommand /home/user/Desktop/graphicsmagick/magick/command.c:8862:27
#6 0x81cd999 in GMCommandSingle /home/user/Desktop/graphicsmagick/magick/command.c:17338:10
#7 0x81cc6ae in GMCommand /home/user/Desktop/graphicsmagick/magick/command.c:17391:16
#8 0x8139511 in main /home/user/Desktop/graphicsmagick/utilities/gm.c:61:10

SUMMARY: AddressSanitizer: heap-buffer-overflow /home/user/Desktop/graphicsmagick/coders/xpm.c:150 ParseColor
Shadow bytes around the buggy address:
0x367c4080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x367c4090: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x367c40a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x367c40b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x367c40c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x367c40d0:[05]fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x367c40e0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x367c40f0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x367c4100: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x367c4110: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x367c4120: 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
==16678==ABORTING

[Bob Friesenhahn]

This issue is fixed by Mercurial changeset 14780:4aa9f9147646.