c - 如何访问用户态内存？

Question

我正在尝试阅读 notepad.exe 的 PEB目前我正在尝试通过注册一个 ProcessCreation 回调然后等待 notepad.exe 创建来访问 PEB。创建记事本后，我使用它的 PID 打开进程并使用 ZwQuerryProcess(PROCESS_BASIC_INFORMATION) 找到 PEB。

但是当我尝试阅读 INFORMATION->PEB 以外的内容时，会引发异常(我认为这是因为我无法访问内存)

当我第一次发现这个时，我记得有人提到了 KeStackAttachProcess，它对应于访问另一个进程上下文中的地址。

问题是我不知道如何检查上下文更改是否成功。一旦我应该在另一个上下文中，我仍然无法访问 peb。有谁知道如何访问记事本的PEB？

这是我目前用来查找和访问 PEB 的代码:

假设 hgtPid = notepad 的 PID

void ModuleDumperThread(){

NTSTATUS Status = STATUS_SUCCESS;
HANDLE hProcessHandle = NULL;
PLIST_ENTRY Next;
PLDR_DATA_TABLE_ENTRY LdrDataTableEntry;
CLIENT_ID clientID; 
ACCESS_MASK DesiredAccess = PROCESS_ALL_ACCESS;
OBJECT_ATTRIBUTES ObjectAttributes;
HANDLE hProcessId = hgtPid;
PROCESS_BASIC_INFORMATION BasicInfoReal;
ULONG SizeReturned;

PEPROCESS ep;
KAPC_STATE *ka_state = NULL;


InitializeObjectAttributes (&ObjectAttributes, NULL, OBJ_KERNEL_HANDLE, NULL, NULL);

   clientID.UniqueProcess = hProcessId;  
   clientID.UniqueThread = NULL; 

__try{


Status = ZwOpenProcess(&hProcessHandle, DesiredAccess, &ObjectAttributes, &clientID);

                if(Status != STATUS_SUCCESS){
                        DbgPrint("Failed to open process\n");
                        DbgPrint("NtStatus: 0x%x", Status);
                        return;
                }

            Status = gZwQueryprocess(hProcessHandle, ProcessBasicInformation, (PVOID)&BasicInfoReal, sizeof(PROCESS_BASIC_INFORMATION), &SizeReturned);

                    if(Status != STATUS_SUCCESS){
                                DbgPrint("gZwQueryprocess failed\n");
                                DbgPrint("Size returned: 0x%x\nNtStatus: 0x%x\n", SizeReturned, Status);
                                ZwClose(hProcessHandle);
                                return;
                    }

            ZwClose(hProcessHandle);        

        Status = PsLookupProcessByProcessId(hProcessId, &ep);

                    if(Status != STATUS_SUCCESS){
                                DbgPrint("PsLookupProcessByProcessId failed\n");
                                DbgPrint("NtStatus: 0x%x\n", Status);
                                return;
                    }

ka_state = ExAllocatePoolWithTag(NonPagedPool, sizeof(KAPC_STATE),'trak');

            KeStackAttachProcess(ep, ka_state);

__try{

                if(BasicInfoReal.PebBaseAddress->Ldr){

                           Next = BasicInfoReal.PebBaseAddress->Ldr->InLoadOrderModuleList.Blink;
                           LdrDataTableEntry = CONTAINING_RECORD( Next,
                                                                  LDR_DATA_TABLE_ENTRY,
                                                                  LoadOrder
                                                                );
                    DbgPrint("Module base address: 0x%x", LdrDataTableEntry->ModuleBaseAddress);
                } 
    }__except( EXCEPTION_EXECUTE_HANDLER ) {
        DbgPrint("Exception while trying to access the PEB\n");
       }

            KeUnstackDetachProcess(ka_state);
            ExFreePool(ka_state);


}__except( EXCEPTION_EXECUTE_HANDLER ) {
                DbgPrint("Exception in ModuleDumper\n");
        }

              if(ep){
                ObDereferenceObject(ep);        
              } 
return;
}

有人发现任何错误/故障吗？

提前致谢

编辑:

我改变了一些东西，这就是它变得非常奇怪的地方。为了确保我将 KeStackAttachProcess() 的“ep”更改为 msdn 指定的 PRKPROCESS 类型，当我调用 KeStackAttachProcess() 现在执行消失了。通话前一切正常，通话后就什么都没有了。没有错误没有异常没有蓝屏死机:没有。 这是怎么回事？!？

变化:

    __asm{
        mov eax, ep
        mov eax, [eax]
        mov myPKPROCESS, eax  // just dereferencing my pointer (I don't have the structs)
    }

  DbgPrint("Test print\n");   // gets printed just fine

            KeStackAttachProcess(&myPKPROCESS, ka_state); 
DbgPrint("Test print\n");  // nothing happens

编辑 2:

我已经解决了这个问题。我仍然不知道上面的代码出了什么问题，但是这段代码似乎可以正常工作:

void ModuleDumperThread(){

NTSTATUS Status = STATUS_SUCCESS;
HANDLE hProcessHandle = NULL;
PLIST_ENTRY Next;
PLDR_DATA_TABLE_ENTRY LdrDataTableEntry;
CLIENT_ID clientID; 
ACCESS_MASK DesiredAccess = PROCESS_ALL_ACCESS;
OBJECT_ATTRIBUTES ObjectAttributes;
HANDLE hProcessId = hgtPid;
PROCESS_BASIC_INFORMATION BasicInfoReal;
ULONG SizeReturned;
PEPROCESS ep = NULL;
unsigned int Index = 0;
InitializeObjectAttributes (&ObjectAttributes, NULL, OBJ_KERNEL_HANDLE, NULL, NULL);

   clientID.UniqueProcess = hProcessId;  
   clientID.UniqueThread = NULL; 


__try{

    Status = ZwOpenProcess(&hProcessHandle, DesiredAccess, &ObjectAttributes, &clientID);

                if(Status != STATUS_SUCCESS){
                        DbgPrint("Failed to open process\n");
                        DbgPrint("NtStatus: 0x%x", Status);
                        return;
                }

            Status = gZwQueryprocess(hProcessHandle, ProcessBasicInformation, (PVOID)&BasicInfoReal, sizeof(PROCESS_BASIC_INFORMATION), &SizeReturned);

                    if(Status != STATUS_SUCCESS){
                                DbgPrint("gZwQueryprocess failed\n"); 
                                DbgPrint("Size returned: 0x%x\nNtStatus: 0x%x\n", SizeReturned, Status);
                                ZwClose(hProcessHandle);
                                return;
                    }

    //DbgPrint("Basic info: 0x%x\n", BasicInfoReal);
    //DbgPrint("BasicInfoReal->PebBaseAddress: 0x%x\n", BasicInfoReal->PebBaseAddress);
    //DbgPrint("RealPeb: 0x%x\n", RealPeb);
    //DbgPrint("gZwReadVirtualMemory: 0x%x\n", gZwReadVirtualMemory);

                    Status = PsLookupProcessByProcessId(hProcessId, &ep);

                    if(Status != STATUS_SUCCESS){
                                DbgPrint("PsLookupProcessByProcessId failed\n");
                                DbgPrint("NtStatus: 0x%x\n", Status);
                                ZwClose(hProcessHandle);
                                return;
                    }
Timeout((INT64)0x1FFFFFF);

KeAttachProcess(ep);
__try{
   DbgPrint("ImageBaseAddress of notepad.exe: 0x%x\n", BasicInfoReal.PebBaseAddress->ImageBaseAddress);

    Next = BasicInfoReal.PebBaseAddress->Ldr->InLoadOrderModuleList.Blink;
    LdrDataTableEntry = CONTAINING_RECORD( Next, LDR_DATA_TABLE_ENTRY, LoadOrder);


    for(Index = 0; Index != 17; Index++){
       DbgPrint("%d: ImageBase of %wZ in Notepad.exe: 0x%x\n", Index, &(LdrDataTableEntry->ModuleName), LdrDataTableEntry->ModuleBaseAddress);
       Next = Next->Blink;
       LdrDataTableEntry = CONTAINING_RECORD(Next, LDR_DATA_TABLE_ENTRY, LoadOrder);
    }


   }__except( EXCEPTION_EXECUTE_HANDLER ) {
                DbgPrint("Exception while accessing the LDR\n");
        }

KeDetachProcess();

    }__except( EXCEPTION_EXECUTE_HANDLER ) {
                DbgPrint("Exception in ModuleDumper\n");
        }
        ObDereferenceObject((PVOID)ep);
        ZwClose(hProcessHandle);    


return;
}

Answer 1

您可以使用 PPEB PsGetProcessPeb(在 PEPROCESS 进程中)。您需要使用 MmGetSystemRoutineAddress 来获取此 API 的地址。查看此文件中的 GetDllByPeb 函数: http://code.google.com/p/arkitlib/source/browse/trunk/ARKitDrv/Ps.c