Allocate in a 32 bit area (Windows C/++)

a.c

static void* allocate_in_32bits(uint32_t start, uint32_t sz) {
	if (!sz) return NULL;
	MEMORY_BASIC_INFORMATION mbi = { 0 };
	char* min = (char*)start;
	char* max = (char*)UINT32_MAX - sz;
	while (min < max) {
		if (!VirtualQuery(min, &mbi, sizeof mbi)) return NULL;
		if (mbi.State == MEM_FREE && mbi.RegionSize > sz && mbi.BaseAddress) {
			void* alloc = VirtualAlloc(mbi.BaseAddress, sz, MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);
			if ((uint64_t)alloc > UINT32_MAX) { VirtualFree(alloc, 0, MEM_RELEASE); return NULL; }
			if (alloc) return alloc;
		}
		min += sz;
	}
	return NULL;
}

int main(int argc, char** argv, char** envp) {
	void* alloc = allocate_in_32bits(UINT16_MAX, 0x1000);
	printf("@ 0x%p", alloc);
	return 0;
}