$ cat t.c
int *glob = 0;
void foo() {
  int local[10];
  glob = local;
}
int main() {
  foo();
  glob[0] = 0;
  return 0;
}
=========================================
$ clang -fsanitize=address -mllvm -asan-use-after-return=1 t.c 
$ ./a.out 
=================================================================
==17961== ERROR: AddressSanitizer: stack-use-after-return on address 0x7ff528542220
at pc 0x40958d bp 0x7fff789b7450 sp 0x7fff789b7448
WRITE of size 4 at 0x7ff528542220 thread T0
    #0 0x40958c (/tmp/a.out+0x40958c)
    #1 0x7ff528d60c4c (/lib/libc-2.11.1.so+0x1ec4c)
==17961== AddressSanitizer CHECK failed: /usr/local/google/chrome/src/third_party/llvm/projects/compiler-rt/lib/asan/asan_report.cc:151
"((name_end)) != (0)" (0x0, 0x0)
    #0 0x412b0f (/tmp/a.out+0x412b0f)
    #1 0x414141 (/tmp/a.out+0x414141)
Stats: 0M malloced (0M for red zones) by 0 calls
Stats: 0M realloced by 0 calls
Stats: 0M freed by 0 calls
Stats: 0M really freed by 0 calls
Stats: 0M (0 full pages) mmaped in 0 calls
  mmaps   by size class: 
  mallocs by size class: 
  frees   by size class: 
  rfrees  by size class: 
Stats: malloc large: 0 small slow: 0