out of bounds heap read in r_core_write_op

[hannob]

Script input:
https://crashes.fuzzing-project.org/radare2-script-oob-heap-read-r_core_write_op
Contains "wo2" string.

Address Sanitizer:

==18188==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x6020000156f4 at pc 0x7f9116ef4d70 bp 0x7ffdeb1b0bd0 sp 0x7ffdeb1b0ba0
READ of size 1 at 0x6020000156f4 thread T0
    #0 0x7f9116ef4d6f in strlen (/usr/lib/gcc/x86_64-pc-linux-gnu/4.9.2/libasan.so.1+0x32d6f)
    #1 0x7f91168a4e1a in r_core_write_op /f/radare2/radare2/libr/core/io.c:113
    #2 0x7f91167eed07 in cmd_write_op /f/radare2/radare2/libr/core/cmd_write.c:81
    #3 0x7f91167eed07 in cmd_write /f/radare2/radare2/libr/core/cmd_write.c:902
    #4 0x7f9116867b1a in r_core_cmd_subst_i /f/radare2/radare2/libr/core/cmd.c:1599
    #5 0x7f91167c8a51 in r_core_cmd_subst /f/radare2/radare2/libr/core/cmd.c:1084
    #6 0x7f91167c9e72 in r_core_cmd /f/radare2/radare2/libr/core/cmd.c:1947
    #7 0x7f91167ccd1c in r_core_cmd_lines /f/radare2/radare2/libr/core/cmd.c:1998
    #8 0x7f91167cd07c in r_core_cmd_file /f/radare2/radare2/libr/core/cmd.c:2010
    #9 0x7f91167d0013 in r_core_run_script /f/radare2/radare2/libr/core/cmd.c:373
    #10 0x405642 in main /f/radare2/radare2/binr/radare2/radare2.c:733
    #11 0x7f9110d1ef9f in __libc_start_main (/lib64/libc.so.6+0x1ff9f)
    #12 0x40a3fd (/mnt/ram/r2/radare2+0x40a3fd)

0x6020000156f4 is located 0 bytes to the right of 4-byte region [0x6020000156f0,0x6020000156f4)
allocated by thread T0 here:
    #0 0x7f9116f196f7 in malloc (/usr/lib/gcc/x86_64-pc-linux-gnu/4.9.2/libasan.so.1+0x576f7)
    #1 0x7f9110d80789 in strdup (/lib64/libc.so.6+0x81789)

SUMMARY: AddressSanitizer: heap-buffer-overflow ??:0 strlen
Shadow bytes around the buggy address:
  0x0c047fffaa80: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fffaa90: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fffaaa0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fffaab0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fffaac0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
=>0x0c047fffaad0: fa fa fa fa fa fa 02 fa fa fa 01 fa fa fa[04]fa
  0x0c047fffaae0: fa fa 04 fa fa fa 04 fa fa fa fd fd fa fa fd fd
  0x0c047fffaaf0: fa fa fd fa fa fa fd fa fa fa fd fa fa fa fd fa
  0x0c047fffab00: fa fa fd fa fa fa fd fa fa fa fd fd fa fa 02 fa
  0x0c047fffab10: fa fa fd fa fa fa fd fd fa fa fd fa fa fa fd fd
  0x0c047fffab20: fa fa fd fa fa fa fd fa fa fa fd fd fa fa fd fd
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
  Contiguous container OOB:fc
  ASan internal:           fe
==18188==ABORTING