1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 | #include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <assert.h>
// BUGGY
int main(int argc, char* argv[]) {
char* s = malloc(sizeof(*s) * 4);
s[0] = 'A'; // first byte inside buffer (=block)
s[1] = 'B';
s[2] = 'C';
s[3] = 'D'; // last byte inside buffer (=block)
s[4] = 'E'; // BUG: Invalid write of size 1 … 0 bytes after a block of size 4 alloc'd
s[5] = '\0'; // BUG: Invalid write of size 1 … 1 bytes after a block of size 4 alloc'd
free(s);
// PROBLEM: We tried to write to memory after the call to free(…).
s[0] = 'Z'; // BUG!!! Invalid write of size 1 after block … free'd
return EXIT_SUCCESS;
}
/* vim: set tabstop=4 shiftwidth=4 fileencoding=utf-8 noexpandtab: */
/*
*/
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