Writing to read only address with kernel driver c++

Question

Im trying to write memory to a user mode process with kernel driver,

the current address im trying to write memory for is read only, I want to write 4 bytes to the current address,

the thing is if i change protection ( page ) of the process with VirtualProtectEx , it works and it writes the memory but this is only on user mode level, my intention is to change the protection of the process from kernel mode, i want to make it READWRITE, then change it back to READ from kernel space,

Now what I tried to do is giving me a BSOD ( blue screen of death ) with error : Kmode_exception_not_handld

I cant understand what in my code is triggering this BSOD my PC have very limited specs and i cant debug in VM to know..

I will write the code that works but in user mode , and what the code is not working for me in kernel space:

here the code that works:

void dispatch::handler(void* info_struct)
{
    PINFO_STRUCT info = (PINFO_STRUCT)info_struct;

    if (info->code == CODE_READ_MEMORY)
    {
        PEPROCESS target_process = NULL;
        if (NT_SUCCESS(PsLookupProcessByProcessId((HANDLE)info->process_id, &target_process)))
        {
            memory::read_memory(target_process, (void*)info->address, &info->buffer, info->size);
        }
        DbgPrintEx(0, 0, "[TEST]: Read Memory\n");
    }
    else if (info->code == CODE_WRITE_MEMORY)
    {
        PEPROCESS target_process = NULL;
        if (NT_SUCCESS(PsLookupProcessByProcessId((HANDLE)info->process_id, &target_process)))
        {


            memory::write_memory(target_process, &info->buffer, (void*)info->address, info->size);

        }
        DbgPrintEx(0, 0, "[TEST]: Write Memory\n");

    }
}


NTSTATUS memory::write_memory(PEPROCESS target_process, void* source, void* target, size_t size)
{
    if (!target_process) { return STATUS_INVALID_PARAMETER; }



    size_t bytes = 0;
    NTSTATUS status = MmCopyVirtualMemory(IoGetCurrentProcess(), source, target_process, target, size, KernelMode, &bytes);
    if (!NT_SUCCESS(status) || !bytes)
    {
        return STATUS_INVALID_ADDRESS;
    }


    return status;
}


int main()

{

DWORD oldprt
ULONG writeTest1 = 3204497152;


VirtualProtectEx(ProcManager::hProcess, (PVOID)(testAddr), 4, PAGE_READWRITE, &oldprt);
driver_control::write_memory(process_id, testAddr, writeTest1);
VirtualProtectEx(ProcManager::hProcess, (PVOID)(testAddr), 4, PAGE_READONLY, &oldprt);

return 0;

}

Now what I want to do is stop using the VirtualProtectEx, and change the PAGE protection to READWRITE from kernel space, so what i did is add this in the dispatch::handler function:

else if (info->code == CODE_WRITE_MEMORY)
{
    PEPROCESS target_process = NULL;
    if (NT_SUCCESS(PsLookupProcessByProcessId((HANDLE)info->process_id, &target_process)))
    {
        PMDL Mdl = IoAllocateMdl((void*)info->address, info->size, FALSE, FALSE, NULL);

        if (!Mdl)
            return false;

        // Locking and mapping memory with RW-rights:
        MmProbeAndLockPages(Mdl, KernelMode, IoReadAccess);
        PVOID Mapping = MmMapLockedPagesSpecifyCache(Mdl, KernelMode, MmNonCached, NULL, FALSE, NormalPagePriority);
        MmProtectMdlSystemAddress(Mdl, PAGE_READWRITE);

        memory::write_memory(target_process, &info->buffer, (void*)info->address, info->size);


        // Resources freeing:
        MmUnmapLockedPages(Mapping, Mdl);
        MmUnlockPages(Mdl);
        IoFreeMdl(Mdl);

    }
    DbgPrintEx(0, 0, "[TEST]: Write Read Only Memory\n");

}

So this what I've added caused the BSOD, but why I cannot understand, what am i doing wrong here?

here is the info struct if needed to understand more, :

#define CODE_READ_MEMORY 0x1
#define CODE_WRITE_MEMORY 0x2

typedef struct _INFO_STRUCT
{
    ULONG code;
    ULONG process_id;
    ULONG address;
    ULONG buffer;
    ULONG size;
}INFO_STRUCT, * PINFO_STRUCT;

any suggestions on solving this problem?