==127145== Memcheck, a memory error detector
==127145== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==127145== Using Valgrind-3.15.0 and LibVEX; rerun with -h for copyright info
==127145== Command: ./invalid_write.after_free
==127145== 
==127145== Invalid write of size 1
==127145==    at 0x40070E: main (invalid_write.after_free.c:21)
==127145==  Address 0x5205041 is 1 bytes inside a block of size 4 free'd
==127145==    at 0x4C2B06D: free (vg_replace_malloc.c:540)
==127145==    by 0x400705: main (invalid_write.after_free.c:19)
==127145==  Block was alloc'd at
==127145==    at 0x4C29F73: malloc (vg_replace_malloc.c:309)
==127145==    by 0x400635: repeat_char (invalid_write.after_free.c:2)
==127145==    by 0x4006E9: main (invalid_write.after_free.c:17)
==127145== 
@@@==127145== 
==127145== HEAP SUMMARY:
==127145==     in use at exit: 0 bytes in 0 blocks
==127145==   total heap usage: 1 allocs, 1 frees, 4 bytes allocated
==127145== 
==127145== All heap blocks were freed -- no leaks are possible
==127145== 
==127145== For lists of detected and suppressed errors, rerun with: -s
==127145== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)