program crashed on c# Pinvoke

i write a c++ dll , and this dll expose method for c# application to invoke,
after add mimalloc to the dll, the program will crash as next image

the c++ dll reletive code:
BYTE* data;
int test1(int a, int b) {

data = (BYTE*)mi_malloc(1920 * 1080);
return a + b;

}

the C# code
static class Program
{
[DllImport(@"Dll1.dll")]
public extern static int test1(int a, int b);

    /// <summary>
    /// 应用程序的主入口点。
    /// </summary>
    [STAThread]
    static void Main()
    {
        test1(1, 3);
        Application.EnableVisualStyles();
        Application.SetCompatibleTextRenderingDefault(false);
        Application.Run(new Form1());
    }
}

Start with the C++ test1 entry point and the C# DllImport declaration shown in the issue, comparing the DLL behavior before and after adding mi_malloc. Reproduce the crash with the provided call, then capture the platform, build details, and stack trace; done means the crash is isolated with a minimal reproduction or its required interop conditions are documented.