#362 SEGV in utilities/gm+0x8080b58) (XPM reader)

[moshe]

This bug was found while fuzzing graphicsmagick with afl-fuzz

Tested on hg changeset 44ed8318ba6a+

Command: gm convert id:000031,sig:06,src:000412,op:flip1,pos:85 /dev/null

ASAN:SIGSEGV

==16724==ERROR: AddressSanitizer: SEGV on unknown address 0xbebebeae (pc 0x08080b59 bp 0xbfe302a8 sp 0xbfe2fe30 T0)
#0 0x8080b58 in __asan::asan_free(void, __sanitizer::BufferedStackTrace, __asan::AllocType) (/home/user/Desktop/graphicsmagick/utilities/gm+0x8080b58)
#1 0x81177e6 in __interceptor_free (/home/user/Desktop/graphicsmagick/utilities/gm+0x81177e6)
#2 0x827f285 in MagickFree /home/user/Desktop/graphicsmagick/magick/memory.c:509:6
#3 0x856bd99 in ReadXPMImage /home/user/Desktop/graphicsmagick/coders/xpm.c:335:5
#4 0x81f84b4 in ReadImage /home/user/Desktop/graphicsmagick/magick/constitute.c:1607:14
#5 0x816fbca in ConvertImageCommand /home/user/Desktop/graphicsmagick/magick/command.c:4348:22
#6 0x8187f6b in MagickCommand /home/user/Desktop/graphicsmagick/magick/command.c:8862:27
#7 0x81cd999 in GMCommandSingle /home/user/Desktop/graphicsmagick/magick/command.c:17338:10
#8 0x81cc6ae in GMCommand /home/user/Desktop/graphicsmagick/magick/command.c:17391:16
#9 0x8139511 in main /home/user/Desktop/graphicsmagick/utilities/gm.c:61:10
#10 0xb756673d in __libc_start_main /build/glibc-tVsQx_/glibc-2.21/csu/libc-start.c:289
#11 0x807fd9b in _start (/home/user/Desktop/graphicsmagick/utilities/gm+0x807fd9b)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV ??:0 __asan::asan_free(void, __sanitizer::BufferedStackTrace, __asan::AllocType)
==16724==ABORTING

[Bob Friesenhahn]

According to ASAN and valgrind, this issue was either already fixed by one of the changesets which resolved one of the other resolved issues, or else I can no longer reproduce it.