在上一篇文章《驅動開發:核心中實現Dump程序轉儲》
中我們實現了ARK工具的轉存功能,本篇文章繼續以記憶體為出發點介紹VAD
結構,該結構的全程是Virtual Address Descriptor
即虛擬地址描述符
,VAD是一個AVL
自平衡二元樹
,樹的每一個節點代表一段虛擬地址空間。程式中的程式碼段,資料段,堆段都會各種佔用一個或多個VAD
節點,由一個MMVAD
結構完整描述。
VAD結構的遍歷效果如下:
那麼這個結構在哪?每一個程序都有自己單獨的VAD
結構樹,這個結構通常在EPROCESS
結構裡面裡面,在核心偵錯模式下使用dt _EPROCESS
可得到如下資訊。
lyshark.com 1: kd> dt _EPROCESS
ntdll!_EPROCESS
+0x500 Vm : _MMSUPPORT_FULL
+0x640 MmProcessLinks : _LIST_ENTRY
+0x650 ModifiedPageCount : Uint4B
+0x654 ExitStatus : Int4B
+0x658 VadRoot : _RTL_AVL_TREE
+0x660 VadHint : Ptr64 Void
+0x668 VadCount : Uint8B
+0x670 VadPhysicalPages : Uint8B
+0x678 VadPhysicalPagesLimit : Uint8B
可以看到在本系統中VAD的偏移是+0x658
緊跟其後的還有vadCount
的計數等。
VAD結構是如何被新增的?通常情況下系統呼叫VirtualAllocate
等申請一段堆記憶體時,則會在VAD樹上增加一個結點_MMVAD
結構體,需要說明的是棧並不受VAD的管理。由系統直接分配空間,並把地址記錄在了TEB中。
lyshark.com 0: kd> dt _MMVAD
nt!_MMVAD
+0x000 Core : _MMVAD_SHORT
+0x040 u2 : <anonymous-tag>
+0x048 Subsection : Ptr64 _SUBSECTION
+0x050 FirstPrototypePte : Ptr64 _MMPTE
+0x058 LastContiguousPte : Ptr64 _MMPTE
+0x060 ViewLinks : _LIST_ENTRY
+0x070 VadsProcess : Ptr64 _EPROCESS
+0x078 u4 : <anonymous-tag>
+0x080 FileObject : Ptr64 _FILE_OBJECT
結構體MMVAD
則是每一個VAD
記憶體塊的屬性,這個記憶體結構定義在WinDBG中可看到。
如上在EPROCESS
結構中可以找到VAD結構的相對偏移+0x658
以及程序VAD計數偏移+0x668
,我們首先通過!process 0 0
指令得到當前所有程序的EPROCESS
結構,並選中程序。
lyshark.com 0: kd> !process 0 0
PROCESS ffffe28fbb0860c0
SessionId: 1 Cid: 11a8 Peb: 0035c000 ParentCid: 11c8
DirBase: 309f3002 ObjectTable: ffffac87ba3da580 HandleCount: 145.
Image: x64.exe
此處的ffffe28fbb0860c0
正是我們所需要的EPROCESS
結構。
當需要得到該程序的VAD結構時,只需要使用!vad ffffe28fbb0860c0 + 0x658
來顯示該程序的VAD樹。
至於獲取VAD有多少條,則可以直接使用!vad ffffe28fbb0860c0 + 0x668
來獲取到。
既然手動可以遍歷出來,那麼自動化也並不難,首先定義標頭檔案vad.h
同樣這是微軟定義,如果想要的到最新的,自己下載WinDBG偵錯核心輸入命令。
#pragma once
#include <ntifs.h>
typedef struct _MM_GRAPHICS_VAD_FLAGS // 15 elements, 0x4 bytes (sizeof)
{
/*0x000*/ ULONG32 Lock : 1; // 0 BitPosition
/*0x000*/ ULONG32 LockContended : 1; // 1 BitPosition
/*0x000*/ ULONG32 DeleteInProgress : 1; // 2 BitPosition
/*0x000*/ ULONG32 NoChange : 1; // 3 BitPosition
/*0x000*/ ULONG32 VadType : 3; // 4 BitPosition
/*0x000*/ ULONG32 Protection : 5; // 7 BitPosition
/*0x000*/ ULONG32 PreferredNode : 6; // 12 BitPosition
/*0x000*/ ULONG32 PageSize : 2; // 18 BitPosition
/*0x000*/ ULONG32 PrivateMemoryAlwaysSet : 1; // 20 BitPosition
/*0x000*/ ULONG32 WriteWatch : 1; // 21 BitPosition
/*0x000*/ ULONG32 FixedLargePageSize : 1; // 22 BitPosition
/*0x000*/ ULONG32 ZeroFillPagesOptional : 1; // 23 BitPosition
/*0x000*/ ULONG32 GraphicsAlwaysSet : 1; // 24 BitPosition
/*0x000*/ ULONG32 GraphicsUseCoherentBus : 1; // 25 BitPosition
/*0x000*/ ULONG32 GraphicsPageProtection : 3; // 26 BitPosition
}MM_GRAPHICS_VAD_FLAGS, *PMM_GRAPHICS_VAD_FLAGS;
typedef struct _MM_PRIVATE_VAD_FLAGS // 15 elements, 0x4 bytes (sizeof)
{
/*0x000*/ ULONG32 Lock : 1; // 0 BitPosition
/*0x000*/ ULONG32 LockContended : 1; // 1 BitPosition
/*0x000*/ ULONG32 DeleteInProgress : 1; // 2 BitPosition
/*0x000*/ ULONG32 NoChange : 1; // 3 BitPosition
/*0x000*/ ULONG32 VadType : 3; // 4 BitPosition
/*0x000*/ ULONG32 Protection : 5; // 7 BitPosition
/*0x000*/ ULONG32 PreferredNode : 6; // 12 BitPosition
/*0x000*/ ULONG32 PageSize : 2; // 18 BitPosition
/*0x000*/ ULONG32 PrivateMemoryAlwaysSet : 1; // 20 BitPosition
/*0x000*/ ULONG32 WriteWatch : 1; // 21 BitPosition
/*0x000*/ ULONG32 FixedLargePageSize : 1; // 22 BitPosition
/*0x000*/ ULONG32 ZeroFillPagesOptional : 1; // 23 BitPosition
/*0x000*/ ULONG32 Graphics : 1; // 24 BitPosition
/*0x000*/ ULONG32 Enclave : 1; // 25 BitPosition
/*0x000*/ ULONG32 ShadowStack : 1; // 26 BitPosition
}MM_PRIVATE_VAD_FLAGS, *PMM_PRIVATE_VAD_FLAGS;
typedef struct _MMVAD_FLAGS // 9 elements, 0x4 bytes (sizeof)
{
/*0x000*/ ULONG32 Lock : 1; // 0 BitPosition
/*0x000*/ ULONG32 LockContended : 1; // 1 BitPosition
/*0x000*/ ULONG32 DeleteInProgress : 1; // 2 BitPosition
/*0x000*/ ULONG32 NoChange : 1; // 3 BitPosition
/*0x000*/ ULONG32 VadType : 3; // 4 BitPosition
/*0x000*/ ULONG32 Protection : 5; // 7 BitPosition
/*0x000*/ ULONG32 PreferredNode : 6; // 12 BitPosition
/*0x000*/ ULONG32 PageSize : 2; // 18 BitPosition
/*0x000*/ ULONG32 PrivateMemory : 1; // 20 BitPosition
}MMVAD_FLAGS, *PMMVAD_FLAGS;
typedef struct _MM_SHARED_VAD_FLAGS // 11 elements, 0x4 bytes (sizeof)
{
/*0x000*/ ULONG32 Lock : 1; // 0 BitPosition
/*0x000*/ ULONG32 LockContended : 1; // 1 BitPosition
/*0x000*/ ULONG32 DeleteInProgress : 1; // 2 BitPosition
/*0x000*/ ULONG32 NoChange : 1; // 3 BitPosition
/*0x000*/ ULONG32 VadType : 3; // 4 BitPosition
/*0x000*/ ULONG32 Protection : 5; // 7 BitPosition
/*0x000*/ ULONG32 PreferredNode : 6; // 12 BitPosition
/*0x000*/ ULONG32 PageSize : 2; // 18 BitPosition
/*0x000*/ ULONG32 PrivateMemoryAlwaysClear : 1; // 20 BitPosition
/*0x000*/ ULONG32 PrivateFixup : 1; // 21 BitPosition
/*0x000*/ ULONG32 HotPatchAllowed : 1; // 22 BitPosition
}MM_SHARED_VAD_FLAGS, *PMM_SHARED_VAD_FLAGS;
typedef struct _MMVAD_FLAGS2 // 7 elements, 0x4 bytes (sizeof)
{
/*0x000*/ ULONG32 FileOffset : 24; // 0 BitPosition
/*0x000*/ ULONG32 Large : 1; // 24 BitPosition
/*0x000*/ ULONG32 TrimBehind : 1; // 25 BitPosition
/*0x000*/ ULONG32 Inherit : 1; // 26 BitPosition
/*0x000*/ ULONG32 NoValidationNeeded : 1; // 27 BitPosition
/*0x000*/ ULONG32 PrivateDemandZero : 1; // 28 BitPosition
/*0x000*/ ULONG32 Spare : 3; // 29 BitPosition
}MMVAD_FLAGS2, *PMMVAD_FLAGS2;
typedef struct _MMVAD_SHORT
{
RTL_BALANCED_NODE VadNode;
UINT32 StartingVpn; /*0x18*/
UINT32 EndingVpn; /*0x01C*/
UCHAR StartingVpnHigh;
UCHAR EndingVpnHigh;
UCHAR CommitChargeHigh;
UCHAR SpareNT64VadUChar;
INT32 ReferenceCount;
EX_PUSH_LOCK PushLock; /*0x028*/
struct
{
union
{
ULONG_PTR flag;
MM_PRIVATE_VAD_FLAGS PrivateVadFlags; /*0x030*/
MMVAD_FLAGS VadFlags;
MM_GRAPHICS_VAD_FLAGS GraphicsVadFlags;
MM_SHARED_VAD_FLAGS SharedVadFlags;
}Flags;
}u1;
PVOID EventList; /*0x038*/
}MMVAD_SHORT, *PMMVAD_SHORT;
typedef struct _MMADDRESS_NODE
{
ULONG64 u1;
struct _MMADDRESS_NODE* LeftChild;
struct _MMADDRESS_NODE* RightChild;
ULONG64 StartingVpn;
ULONG64 EndingVpn;
}MMADDRESS_NODE, *PMMADDRESS_NODE;
typedef struct _MMEXTEND_INFO // 2 elements, 0x10 bytes (sizeof)
{
/*0x000*/ UINT64 CommittedSize;
/*0x008*/ ULONG32 ReferenceCount;
/*0x00C*/ UINT8 _PADDING0_[0x4];
}MMEXTEND_INFO, *PMMEXTEND_INFO;
struct _SEGMENT
{
struct _CONTROL_AREA* ControlArea;
ULONG TotalNumberOfPtes;
ULONG SegmentFlags;
ULONG64 NumberOfCommittedPages;
ULONG64 SizeOfSegment;
union
{
struct _MMEXTEND_INFO* ExtendInfo;
void* BasedAddress;
}u;
ULONG64 SegmentLock;
ULONG64 u1;
ULONG64 u2;
PVOID* PrototypePte;
ULONGLONG ThePtes[0x1];
};
typedef struct _EX_FAST_REF
{
union
{
PVOID Object;
ULONG_PTR RefCnt : 3;
ULONG_PTR Value;
};
} EX_FAST_REF, *PEX_FAST_REF;
typedef struct _CONTROL_AREA // 17 elements, 0x80 bytes (sizeof)
{
/*0x000*/ struct _SEGMENT* Segment;
union // 2 elements, 0x10 bytes (sizeof)
{
/*0x008*/ struct _LIST_ENTRY ListHead; // 2 elements, 0x10 bytes (sizeof)
/*0x008*/ VOID* AweContext;
};
/*0x018*/ UINT64 NumberOfSectionReferences;
/*0x020*/ UINT64 NumberOfPfnReferences;
/*0x028*/ UINT64 NumberOfMappedViews;
/*0x030*/ UINT64 NumberOfUserReferences;
/*0x038*/ ULONG32 u; // 2 elements, 0x4 bytes (sizeof)
/*0x03C*/ ULONG32 u1; // 2 elements, 0x4 bytes (sizeof)
/*0x040*/ struct _EX_FAST_REF FilePointer; // 3 elements, 0x8 bytes (sizeof)
// 4 elements, 0x8 bytes (sizeof)
}CONTROL_AREA, *PCONTROL_AREA;
typedef struct _SUBSECTION_
{
struct _CONTROL_AREA* ControlArea;
}SUBSECTION, *PSUBSECTION;
typedef struct _MMVAD
{
MMVAD_SHORT Core;
union /*0x040*/
{
UINT32 LongFlags2;
//現在用不到省略
MMVAD_FLAGS2 VadFlags2;
}u2;
PSUBSECTION Subsection; /*0x048*/
PVOID FirstPrototypePte; /*0x050*/
PVOID LastContiguousPte; /*0x058*/
LIST_ENTRY ViewLinks; /*0x060*/
PEPROCESS VadsProcess; /*0x070*/
PVOID u4; /*0x078*/
PVOID FileObject; /*0x080*/
}MMVAD, *PMMVAD;
typedef struct _RTL_AVL_TREE // 1 elements, 0x8 bytes (sizeof)
{
/*0x000*/ struct _RTL_BALANCED_NODE* Root;
}RTL_AVL_TREE, *PRTL_AVL_TREE;
typedef struct _VAD_INFO_
{
ULONG_PTR pVad;
ULONG_PTR startVpn;
ULONG_PTR endVpn;
ULONG_PTR pFileObject;
ULONG_PTR flags;
}VAD_INFO, *PVAD_INFO;
typedef struct _ALL_VADS_
{
ULONG nCnt;
VAD_INFO VadInfos[1];
}ALL_VADS, *PALL_VADS;
typedef struct _MMSECTION_FLAGS // 27 elements, 0x4 bytes (sizeof)
{
/*0x000*/ UINT32 BeingDeleted : 1; // 0 BitPosition
/*0x000*/ UINT32 BeingCreated : 1; // 1 BitPosition
/*0x000*/ UINT32 BeingPurged : 1; // 2 BitPosition
/*0x000*/ UINT32 NoModifiedWriting : 1; // 3 BitPosition
/*0x000*/ UINT32 FailAllIo : 1; // 4 BitPosition
/*0x000*/ UINT32 Image : 1; // 5 BitPosition
/*0x000*/ UINT32 Based : 1; // 6 BitPosition
/*0x000*/ UINT32 File : 1; // 7 BitPosition
/*0x000*/ UINT32 AttemptingDelete : 1; // 8 BitPosition
/*0x000*/ UINT32 PrefetchCreated : 1; // 9 BitPosition
/*0x000*/ UINT32 PhysicalMemory : 1; // 10 BitPosition
/*0x000*/ UINT32 ImageControlAreaOnRemovableMedia : 1; // 11 BitPosition
/*0x000*/ UINT32 Reserve : 1; // 12 BitPosition
/*0x000*/ UINT32 Commit : 1; // 13 BitPosition
/*0x000*/ UINT32 NoChange : 1; // 14 BitPosition
/*0x000*/ UINT32 WasPurged : 1; // 15 BitPosition
/*0x000*/ UINT32 UserReference : 1; // 16 BitPosition
/*0x000*/ UINT32 GlobalMemory : 1; // 17 BitPosition
/*0x000*/ UINT32 DeleteOnClose : 1; // 18 BitPosition
/*0x000*/ UINT32 FilePointerNull : 1; // 19 BitPosition
/*0x000*/ ULONG32 PreferredNode : 6; // 20 BitPosition
/*0x000*/ UINT32 GlobalOnlyPerSession : 1; // 26 BitPosition
/*0x000*/ UINT32 UserWritable : 1; // 27 BitPosition
/*0x000*/ UINT32 SystemVaAllocated : 1; // 28 BitPosition
/*0x000*/ UINT32 PreferredFsCompressionBoundary : 1; // 29 BitPosition
/*0x000*/ UINT32 UsingFileExtents : 1; // 30 BitPosition
/*0x000*/ UINT32 PageSize64K : 1; // 31 BitPosition
}MMSECTION_FLAGS, *PMMSECTION_FLAGS;
typedef struct _SECTION // 9 elements, 0x40 bytes (sizeof)
{
/*0x000*/ struct _RTL_BALANCED_NODE SectionNode; // 6 elements, 0x18 bytes (sizeof)
/*0x018*/ UINT64 StartingVpn;
/*0x020*/ UINT64 EndingVpn;
/*0x028*/ union {
PCONTROL_AREA ControlArea;
PVOID FileObject;
}u1; // 4 elements, 0x8 bytes (sizeof)
/*0x030*/ UINT64 SizeOfSection;
/*0x038*/ union {
ULONG32 LongFlags;
MMSECTION_FLAGS Flags;
}u; // 2 elements, 0x4 bytes (sizeof)
struct // 3 elements, 0x4 bytes (sizeof)
{
/*0x03C*/ ULONG32 InitialPageProtection : 12; // 0 BitPosition
/*0x03C*/ ULONG32 SessionId : 19; // 12 BitPosition
/*0x03C*/ ULONG32 NoValidationNeeded : 1; // 31 BitPosition
};
}SECTION, *PSECTION;
引入vad.h
標頭檔案,並寫入如下程式碼,此處的eprocess_offset_VadRoot
以及eprocess_offset_VadCount
則是上方得出的相對於EPROCESS
結構的偏移值,每個系統都不一樣,版本不同偏移值會不同。
#include "vad.h"
#include <ntifs.h>
// 定義VAD相對於EProcess頭部偏移值
#define eprocess_offset_VadRoot 0x658
#define eprocess_offset_VadCount 0x668
VOID EnumVad(PMMVAD Root, PALL_VADS pBuffer, ULONG nCnt)
{
if (!Root || !pBuffer || !nCnt)
{
return;
}
__try
{
if (nCnt > pBuffer->nCnt)
{
// 得到起始頁與結束頁
ULONG64 endptr = (ULONG64)Root->Core.EndingVpnHigh;
endptr = endptr << 32;
ULONG64 startptr = (ULONG64)Root->Core.StartingVpnHigh;
startptr = startptr << 32;
// 得到根節點
pBuffer->VadInfos[pBuffer->nCnt].pVad = (ULONG_PTR)Root;
// 起始頁: startingVpn * 0x1000
pBuffer->VadInfos[pBuffer->nCnt].startVpn = (startptr | Root->Core.StartingVpn) << PAGE_SHIFT;
// 結束頁: EndVpn * 0x1000 + 0xfff
pBuffer->VadInfos[pBuffer->nCnt].endVpn = ((endptr | Root->Core.EndingVpn) << PAGE_SHIFT) + 0xfff;
// VAD標誌 928 = Mapped 1049088 = Private ....
pBuffer->VadInfos[pBuffer->nCnt].flags = Root->Core.u1.Flags.flag;
// 驗證節點可讀性
if (MmIsAddressValid(Root->Subsection) && MmIsAddressValid(Root->Subsection->ControlArea))
{
if (MmIsAddressValid((PVOID)((Root->Subsection->ControlArea->FilePointer.Value >> 4) << 4)))
{
pBuffer->VadInfos[pBuffer->nCnt].pFileObject = ((Root->Subsection->ControlArea->FilePointer.Value >> 4) << 4);
}
}
pBuffer->nCnt++;
}
if (MmIsAddressValid(Root->Core.VadNode.Left))
{
// 遞迴列舉左子樹
EnumVad((PMMVAD)Root->Core.VadNode.Left, pBuffer, nCnt);
}
if (MmIsAddressValid(Root->Core.VadNode.Right))
{
// 遞迴列舉右子樹
EnumVad((PMMVAD)Root->Core.VadNode.Right, pBuffer, nCnt);
}
}
__except (1)
{
}
}
BOOLEAN EnumProcessVad(ULONG Pid, PALL_VADS pBuffer, ULONG nCnt)
{
PEPROCESS Peprocess = 0;
PRTL_AVL_TREE Table = NULL;
PMMVAD Root = NULL;
// 通過程序PID得到程序EProcess
if (NT_SUCCESS(PsLookupProcessByProcessId((HANDLE)Pid, &Peprocess)))
{
// 與偏移相加得到VAD頭節點
Table = (PRTL_AVL_TREE)((UCHAR*)Peprocess + eprocess_offset_VadRoot);
if (!MmIsAddressValid(Table) || !eprocess_offset_VadRoot)
{
return FALSE;
}
__try
{
// 取出頭節點
Root = (PMMVAD)Table->Root;
if (nCnt > pBuffer->nCnt)
{
// 得到起始頁與結束頁
ULONG64 endptr = (ULONG64)Root->Core.EndingVpnHigh;
endptr = endptr << 32;
ULONG64 startptr = (ULONG64)Root->Core.StartingVpnHigh;
startptr = startptr << 32;
pBuffer->VadInfos[pBuffer->nCnt].pVad = (ULONG_PTR)Root;
// 起始頁: startingVpn * 0x1000
pBuffer->VadInfos[pBuffer->nCnt].startVpn = (startptr | Root->Core.StartingVpn) << PAGE_SHIFT;
// 結束頁: EndVpn * 0x1000 + 0xfff
pBuffer->VadInfos[pBuffer->nCnt].endVpn = (endptr | Root->Core.EndingVpn) << PAGE_SHIFT;
pBuffer->VadInfos[pBuffer->nCnt].flags = Root->Core.u1.Flags.flag;
if (MmIsAddressValid(Root->Subsection) && MmIsAddressValid(Root->Subsection->ControlArea))
{
if (MmIsAddressValid((PVOID)((Root->Subsection->ControlArea->FilePointer.Value >> 4) << 4)))
{
pBuffer->VadInfos[pBuffer->nCnt].pFileObject = ((Root->Subsection->ControlArea->FilePointer.Value >> 4) << 4);
}
}
pBuffer->nCnt++;
}
// 列舉左子樹
if (Table->Root->Left)
{
EnumVad((MMVAD*)Table->Root->Left, pBuffer, nCnt);
}
// 列舉右子樹
if (Table->Root->Right)
{
EnumVad((MMVAD*)Table->Root->Right, pBuffer, nCnt);
}
}
__finally
{
ObDereferenceObject(Peprocess);
}
}
else
{
return FALSE;
}
return TRUE;
}
VOID UnDriver(PDRIVER_OBJECT driver)
{
DbgPrint(("Uninstall Driver Is OK \n"));
}
NTSTATUS DriverEntry(IN PDRIVER_OBJECT Driver, PUNICODE_STRING RegistryPath)
{
DbgPrint(("hello lyshark \n"));
typedef struct
{
ULONG nPid;
ULONG nSize;
PALL_VADS pBuffer;
}VADProcess;
__try
{
VADProcess vad = { 0 };
vad.nPid = 4520;
// 預設有1000個執行緒
vad.nSize = sizeof(VAD_INFO) * 0x5000 + sizeof(ULONG);
// 分配臨時空間
vad.pBuffer = (PALL_VADS)ExAllocatePool(PagedPool, vad.nSize);
// 根據傳入長度得到列舉數量
ULONG nCount = (vad.nSize - sizeof(ULONG)) / sizeof(VAD_INFO);
// 列舉VAD
EnumProcessVad(vad.nPid, vad.pBuffer, nCount);
// 輸出VAD
for (size_t i = 0; i < vad.pBuffer->nCnt; i++)
{
DbgPrint("StartVPN = %p | ", vad.pBuffer->VadInfos[i].startVpn);
DbgPrint("EndVPN = %p | ", vad.pBuffer->VadInfos[i].endVpn);
DbgPrint("PVAD = %p | ", vad.pBuffer->VadInfos[i].pVad);
DbgPrint("Flags = %d | ", vad.pBuffer->VadInfos[i].flags);
DbgPrint("pFileObject = %p \n", vad.pBuffer->VadInfos[i].pFileObject);
}
}
__except (1)
{
}
Driver->DriverUnload = UnDriver;
return STATUS_SUCCESS;
}
程式執行後輸出效果如下: