FORTIFY_SOURCE: strlen check.

This test is designed to detect code such as:

int main() {
  char buf[10];
  memcpy(buf, "1234567890", sizeof(buf));
  size_t len = strlen(buf); // segfault here with _FORTIFY_SOURCE
  printf("%d\n", len);
  return 0;

or anytime strlen reads beyond an object boundary. This should
help address memory leakage vulnerabilities and make other
unrelated vulnerabilities harder to exploit.

Change-Id: I354b425be7bef4713c85f6bab0e9738445e00182
3 files changed