heap overflow

[XiaoyuHe]

# enviroment
ubuntu 18.04
./jhead poc

# version
3.04

# asan out
File name : poc12
File size : 3872 bytes
File date : 2021:03:20 21:53:33
Resolution : 139 x 139
JPEG Quality : 81
=================================================================
==818==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x6030000000eb at pc 0x563f92fe5601 bp 0x7ffc2d837530 sp 0x7ffc2d837520
READ of size 1 at 0x6030000000eb thread T0
    #0 0x563f92fe5600 in show_IPTC iptc.c:82
    #1 0x563f92fbd8bb in ProcessFile jhead.c:955
    #2 0x563f92fb8b2e in main jhead.c:1756
    #3 0x7f9954c21bf6 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21bf6)
    #4 0x563f92fbb279 in _start (/home/fuzz/jhead-3.04/jhead+0x12279)

0x6030000000eb is located 7 bytes to the right of 20-byte region [0x6030000000d0,0x6030000000e4)
allocated by thread T0 here:
    #0 0x7f995546db40 in __interceptor_malloc (/usr/lib/x86_64-linux-gnu/libasan.so.4+0xdeb40)
    #1 0x7f9954cd32c8 (/lib/x86_64-linux-gnu/libc.so.6+0xd32c8)

SUMMARY: AddressSanitizer: heap-buffer-overflow iptc.c:82 in show_IPTC
Shadow bytes around the buggy address:
  0x0c067fff7fc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c067fff7fd0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c067fff7fe0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c067fff7ff0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c067fff8000: fa fa 00 00 00 04 fa fa 00 00 01 fa fa fa 00 00
=>0x0c067fff8010: 00 07 fa fa 00 00 00 07 fa fa 00 00 04[fa]fa fa
  0x0c067fff8020: 00 00 04 fa fa fa 00 00 04 fa fa fa fa fa fa fa
  0x0c067fff8030: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c067fff8040: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c067fff8050: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c067fff8060: 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
==818==ABORTING