[win/asan] windows_hook_rtl_allocators=1 breaks CreateProcess

[zmodem]

Reproducer courtesy of @danakj

Consider:

#include <stdio.h>
#include <windows.h>

int main(int argc, char* argv[]) {
  STARTUPINFOA startup_info;
  ZeroMemory(&startup_info, sizeof(startup_info));
  startup_info.cb = sizeof(startup_info);

  PROCESS_INFORMATION process_info;
  ZeroMemory(&process_info, sizeof(process_info));

  if (CreateProcessA("C:\\Windows\\System32\\cmd.exe", NULL, NULL, NULL, FALSE, 0, NULL, NULL, &startup_info, &process_info)) {
    fprintf(stderr, "OK!\n");

    CloseHandle(process_info.hThread);
    WaitForSingleObject(process_info.hProcess, INFINITE);
    CloseHandle(process_info.hProcess);
  } else {
    fprintf(stderr, "FAILED! %d\n", (int)GetLastError());
    return 1;
  }
}

Building with ASan and running without any special flags, it works:

C:\src\llvm-project>build\bin\clang-cl -fsanitize=address \src\temp\a.cc

C:\src\llvm-project>a.exe
OK!
Microsoft Windows [Version 10.0.19045.4894]
(c) Microsoft Corporation. All rights reserved.

Setting windows_hook_rtl_allocators (introduced in c9fa99d) causes it to fail:

C:\src\llvm-project>set ASAN_OPTIONS=windows_hook_rtl_allocators=1

C:\src\llvm-project>a.exe
FAILED! 87

[zmodem]

+cc @mcgov and @barcharcraz

[barcharcraz]

I looked to see if we have reports of this internally, and it doesn't seem we do. I'll try and reproduce the error with our version of asan.

This may take a few weeks for me: I am currently distracted by a number of other things.