heap-buffer-overflow in dcputs at decompile.c:105

[SuhwanSong]

I found a heap-buffer-overflow in dcputs at decompile.c:105
How to reproduce:
$ swftocxx $PoC

Version : 0.4.8
commit 5009802

PoC
Asan log

==22645==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x7f248929b800 at pc 0x561e4b61e4af bp 0x7fff900b5630 sp 0x7fff900b5620
WRITE of size 1 at 0x7f248929b800 thread T0
    #0 0x561e4b61e4ae in dcputchar /home/suhwan/project/program/libming/util/decompile.c:116
    #1 0x561e4b62c32e in decompileCALLMETHOD /home/suhwan/project/program/libming/util/decompile.c:2921
    #2 0x561e4b62d9f3 in decompileAction /home/suhwan/project/program/libming/util/decompile.c:3360
    #3 0x561e4b62dda9 in decompileActions /home/suhwan/project/program/libming/util/decompile.c:3494
    #4 0x561e4b62b8a1 in decompileDEFINEFUNCTION /home/suhwan/project/program/libming/util/decompile.c:2834
    #5 0x561e4b62d9c1 in decompileAction /home/suhwan/project/program/libming/util/decompile.c:3354
    #6 0x561e4b62dda9 in decompileActions /home/suhwan/project/program/libming/util/decompile.c:3494
    #7 0x561e4b62dedf in decompile5Action /home/suhwan/project/program/libming/util/decompile.c:3517
    #8 0x561e4b61a0f3 in outputSWF_DOACTION /home/suhwan/project/program/libming/util/outputscript.c:1551
    #9 0x561e4b61c703 in outputBlock /home/suhwan/project/program/libming/util/outputscript.c:2083
    #10 0x561e4b61d7d0 in readMovie /home/suhwan/project/program/libming/util/main.c:281
    #11 0x561e4b61df64 in main /home/suhwan/project/program/libming/util/main.c:354
    #12 0x7f2493996b96 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21b96)
    #13 0x561e4b60fff9 in _start (/home/suhwan/project/fuzz-input-validate/test/asan/swftocxx+0x13ff9)

0x7f248929b800 is located 0 bytes to the right of 204800-byte region [0x7f2489269800,0x7f248929b800)
allocated by thread T0 here:
    #0 0x7f2494715f40 in realloc (/usr/lib/x86_64-linux-gnu/libasan.so.4+0xdef40)
    #1 0x561e4b61e362 in dcchkstr /home/suhwan/project/program/libming/util/decompile.c:93
    #2 0x561e4b61e3d0 in dcputs /home/suhwan/project/program/libming/util/decompile.c:104
    #3 0x561e4b61e62f in dcprintf /home/suhwan/project/program/libming/util/decompile.c:130
    #4 0x561e4b6220b1 in decompilePUSHPARAM /home/suhwan/project/program/libming/util/decompile.c:886
    #5 0x561e4b624ab4 in decompileINCR_DECR /home/suhwan/project/program/libming/util/decompile.c:1620
    #6 0x561e4b62d87c in decompileAction /home/suhwan/project/program/libming/util/decompile.c:3315
    #7 0x561e4b62dda9 in decompileActions /home/suhwan/project/program/libming/util/decompile.c:3494
    #8 0x561e4b62b8a1 in decompileDEFINEFUNCTION /home/suhwan/project/program/libming/util/decompile.c:2834
    #9 0x561e4b62d9c1 in decompileAction /home/suhwan/project/program/libming/util/decompile.c:3354
    #10 0x561e4b62dda9 in decompileActions /home/suhwan/project/program/libming/util/decompile.c:3494
    #11 0x561e4b62dedf in decompile5Action /home/suhwan/project/program/libming/util/decompile.c:3517
    #12 0x561e4b61a0f3 in outputSWF_DOACTION /home/suhwan/project/program/libming/util/outputscript.c:1551
    #13 0x561e4b61c703 in outputBlock /home/suhwan/project/program/libming/util/outputscript.c:2083
    #14 0x561e4b61d7d0 in readMovie /home/suhwan/project/program/libming/util/main.c:281
    #15 0x561e4b61df64 in main /home/suhwan/project/program/libming/util/main.c:354
    #16 0x7f2493996b96 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21b96)

SUMMARY: AddressSanitizer: heap-buffer-overflow /home/suhwan/project/program/libming/util/decompile.c:116 in dcputchar
Shadow bytes around the buggy address:
  0x0fe51124b6b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0fe51124b6c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0fe51124b6d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0fe51124b6e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0fe51124b6f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x0fe51124b700:[fa]fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0fe51124b710: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0fe51124b720: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0fe51124b730: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0fe51124b740: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0fe51124b750: 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
==22645==ABORTING