How to use ZwQueryInformationProcess to get ProcessImageFileName in a kernel driver?

Question

I\'m writing a simple kernel driver for my application (think of a very simple anti-malware application.)

I\'ve hooked ZwOpenFile() and used PsGetCurr

Answer 1

//Declare this piece of code in header file if available otherwise before the Function definition..

typedef NTSTATUS (*QUERY_INFO_PROCESS) (
__in HANDLE ProcessHandle,
__in PROCESSINFOCLASS ProcessInformationClass,
__out_bcount(ProcessInformationLength) PVOID ProcessInformation,
__in ULONG ProcessInformationLength,
__out_opt PULONG ReturnLength
);

QUERY_INFO_PROCESS ZwQueryInformationProcess;

//Function Definition

NTSTATUS GetProcessImageName(HANDLE processId, PUNICODE_STRING ProcessImageName)
{
NTSTATUS status;
ULONG returnedLength;
ULONG bufferLength;
HANDLE hProcess;
PVOID buffer;
PEPROCESS eProcess;
PUNICODE_STRING imageName;

PAGED_CODE(); // this eliminates the possibility of the IDLE Thread/Process

status = PsLookupProcessByProcessId(processId, &eProcess);

if(NT_SUCCESS(status))
{
    status = ObOpenObjectByPointer(eProcess,0, NULL, 0,0,KernelMode,&hProcess);
    if(NT_SUCCESS(status))
    {
    } else {
        DbgPrint("ObOpenObjectByPointer Failed: %08x\n", status);
    }
    ObDereferenceObject(eProcess);
} else {
    DbgPrint("PsLookupProcessByProcessId Failed: %08x\n", status);
}


if (NULL == ZwQueryInformationProcess) {

    UNICODE_STRING routineName;

    RtlInitUnicodeString(&routineName, L"ZwQueryInformationProcess");

    ZwQueryInformationProcess =
           (QUERY_INFO_PROCESS) MmGetSystemRoutineAddress(&routineName);

    if (NULL == ZwQueryInformationProcess) {
        DbgPrint("Cannot resolve ZwQueryInformationProcess\n");
    }
}

/* Query the actual size of the process path */
status = ZwQueryInformationProcess( hProcess,
                                    ProcessImageFileName,
                                    NULL, // buffer
                                    0, // buffer size
                                    &returnedLength);

if (STATUS_INFO_LENGTH_MISMATCH != status) {
    return status;
}

/* Check there is enough space to store the actual process
   path when it is found. If not return an error with the
   required size */
bufferLength = returnedLength - sizeof(UNICODE_STRING);
if (ProcessImageName->MaximumLength < bufferLength)
{
    ProcessImageName->MaximumLength = (USHORT) bufferLength;
    return STATUS_BUFFER_OVERFLOW;   
}

/* Allocate a temporary buffer to store the path name */
buffer = ExAllocatePoolWithTag(NonPagedPool, returnedLength, 'uLT1');

if (NULL == buffer) 
{
    return STATUS_INSUFFICIENT_RESOURCES;   
}

/* Retrieve the process path from the handle to the process */
status = ZwQueryInformationProcess( hProcess,
                                    ProcessImageFileName,
                                    buffer,
                                    returnedLength,
                                    &returnedLength);

if (NT_SUCCESS(status)) 
{
    /* Copy the path name */
    imageName = (PUNICODE_STRING) buffer;
    RtlCopyUnicodeString(ProcessImageName, imageName);
}

/* Free the temp buffer which stored the path */
ExFreePoolWithTag(buffer, 'uLT1');

return status;
}

//Function Call.. Write this piece of code in PreOperation Call back and IRQ should be PASSIVE_LEVEL

PEPROCESS objCurProcess=NULL;
HANDLE hProcess;
UNICODE_STRING fullPath;

objCurProcess=IoThreadToProcess(Data->Thread);//Note: Date is type of FLT_CALLBACK_DATA which is in PreOperation Callback as argument

hProcess=PsGetProcessID(objCurProcess);

fullPath.Length=0;
fullPath.MaximumLength=520;
fullPath.Buffer=(PWSTR)ExAllocatePoolWithTag(NonPagedPool,520,'uUT1');

GetProcessImageName(hProcess,&fullPath);

in fullPath variable there is Full Path of Process .. Like if the process is explorer.exe then path will be look like this:-

\Device\HarddiskVolume3\Windows\explorer.exe

Note:- \Device\HarddiskVolume3 Path might be changed due to Machine and different volume in hard disk this is an example in my case.