Windows Container逆向工程分析
2024-3-1 12:1:32 Author: mp.weixin.qq.com(查看原文) 阅读量:6 收藏

    windows容器基于两种机制实现，一个使用虚拟化技术将container放在hypvervirsor中执行，另一个是使用叫做server silo的技术利用内核提供的namespace隔离机制。本文只分析server silo的实现机制，基于win10专业版10.0.19045进行逆向工程分析。

2.1 sdk定义

  微软公司未提供server silo的用户态接口信息，内核接口可以在ntddk.h中找到，这意味着微软不希望用户使用容器技术，只有微软公司自身才能使用。

  Server silo基于windows job来实现，首先建立一个job object，然后使用SetInformationJobObject函数启动silo，可以在winnt.h中看到以下定义：

typedef enum _JOBOBJECTINFOCLASS {
...
JobObjectCreateSilo=35,
JobObjectSiloBasicInformation,
JobObjectReserved15Information = 37,
JobObjectReserved16Information = 38,
JobObjectReserved17Information = 39,
JobObjectReserved18Information = 40,
JobObjectReserved19Information = 41,
JobObjectReserved20Information = 42,
JobObjectReserved21Information = 43,
JobObjectReserved22Information = 44,
JobObjectReserved23Information = 45,
JobObjectReserved24Information = 46,
  JobObjectReserved25Information = 47,
MaxJobObjectInfoClass
} JOBOBJECTINFOCLASS;

  黄色部分是silo要使用的值，但是虽然在头文件中找到了JobObjectSiloBasicInformation的定义，但是在笔者的win10专业版本的内核中并未提供此接口的实现，猜测可能在win10 server中有相关实现。

typedef struct _SILOOBJECT_BASIC_INFORMATION {
DWORD SiloId;
DWORD SiloParentId;
DWORD NumberOfProcesses;
BOOLEAN IsInServerSilo;
BYTE  Reserved[3];
} SILOOBJECT_BASIC_INFORMATION, *PSILOOBJECT_BASIC_INFORMATION;
typedef enum _SERVERSILO_STATE {
SERVERSILO_INITING = 0,
SERVERSILO_STARTED,
SERVERSILO_SHUTTING_DOWN,
SERVERSILO_TERMINATING,
SERVERSILO_TERMINATED,
} SERVERSILO_STATE, *PSERVERSILO_STATE;
typedef struct _SERVERSILO_BASIC_INFORMATION {
DWORD ServiceSessionId;
SERVERSILO_STATE State;
DWORD    ExitStatus;
} SERVERSILO_BASIC_INFORMATION, *PSERVERSILO_BASIC_INFORMATION;

  这个接口的相关顺序如下：

1、首先使用35调用PspCreateSilo分配一个silo storage并设置silo标志。

2、使用37建立silo的root directory和相关namespace空间。

3、使用40进一步做silo的初始化。

4、使用41结束silo服务。

5、使用47控制silo服务状态。

2.2 相关内核数据结构

lkd> dt nt!_eprocess
+0x464 BreakOnTermination : Pos 13, 1 Bit
+0x510 Job              : Ptr64 _EJOB
lkd> dt nt!_ejob
+0x430 ParentJob        : Ptr64 _EJOB
+0x438 RootJob          : Ptr64 _EJOB
+0x4d4 JobId            : Uint4B
+0x4d8 ContainerId      : _GUID
+0x4e8 ContainerTelemetryId : _GUID
+0x4f8 ServerSiloGlobals : Ptr64 _ESERVERSILO_GLOBALS
+0x500 PropertySet      : _PS_PROPERTY_SET
+0x518 Storage          : Ptr64 _PSP_STORAGE
+0x528 Silo             : Pos 30, 1 Bit
+0x528 ContainerTelemetryIdSet : Pos 31, 1 Bit
+0x52c JobFlags2        : Uint4B
+0x52c ParentLocked     : Pos 0, 1 Bit
+0x52c EnableUsermodeSiloThreadImpersonation : Pos 1, 1 Bit
+0x52c DisallowUsermodeSiloThreadImpersonation : Pos 2, 1 Bit
+0x5f0 SiloHardReferenceCount : Int8B

_ESERVERSILO_GLOBALS结构保存silo的状态信息。

1: kd> dt nt!_ESERVERSILO_GLOBALS
+0x000 ObSiloState      : _OBP_SILODRIVERSTATE
+0x2e0 SeSiloState      : _SEP_SILOSTATE
+0x310 SeRmSiloState    : _SEP_RM_LSA_CONNECTION_STATE
+0x360 EtwSiloState     : Ptr64 _ETW_SILODRIVERSTATE
+0x368 MiSessionLeaderProcess : Ptr64 _EPROCESS
+0x370 ExpDefaultErrorPortProcess : Ptr64 _EPROCESS
+0x378 ExpDefaultErrorPort : Ptr64 Void
+0x380 HardErrorState   : Uint4B
+0x388 ExpLicenseState  : Ptr64 _EXP_LICENSE_STATE
+0x390 WnfSiloState     : _WNF_SILODRIVERSTATE
+0x3c8 DbgkSiloState    : _DBGK_SILOSTATE
+0x3e8 PsProtectedCurrentDirectory : _UNICODE_STRING
+0x3f8 PsProtectedEnvironment : _UNICODE_STRING
+0x408 ApiSetSection    : Ptr64 Void
+0x410 ApiSetSchema     : Ptr64 Void
+0x418 OneCoreForwardersEnabled : UChar
+0x419 TzVirtualizationSupported : UChar
+0x420 ImgFileExecOptions : Ptr64 Void
+0x428 ExTimeZoneState  : Ptr64 _EX_TIMEZONE_STATE
+0x430 NtSystemRoot     : _UNICODE_STRING
+0x440 SiloRootDirectoryName : _UNICODE_STRING
+0x450 Storage          : Ptr64 _PSP_STORAGE
+0x458 State            : _SERVERSILO_STATE
+0x45c ExitStatus       : Int4B
+0x460 DeleteEvent      : Ptr64 _KEVENT
+0x468 UserSharedData   : Ptr64 _SILO_USER_SHARED_DATA
+0x470 UserSharedSection : Ptr64 Void
+0x478 TerminateWorkItem : _WORK_QUEUE_ITEM
+0x498 IsDownlevelContainer : UChar

2.3内核接口实现

2.3.1 PspCreateSilo

  建立silo的storage结构。

PAGE:00000001405D3FAC PspCreateSilo proc near               ; CODE XREF: NtSetInformationJobObject+1A1C↓p
PAGE:00000001405D3FAC
PAGE:00000001405D3FD2 call    PsIsCurrentThreadInServerSilo
PAGE:00000001405D3FD7 test    al, al
PAGE:00000001405D3FD9 jz      short loc_1405D3FE5
PAGE:00000001405D3FDB mov     eax, 0C0000061h
PAGE:00000001405D3FE0 jmp     loc_1405D4088

  如果当前进程已经有一个silo，则直接返回。

PAGE:00000001405D3FE5 cmp     [rbx+518h], rdi
PAGE:00000001405D3FEC jnz     short loc_1405D4005
PAGE:00000001405D3FEE lea     rcx, [rsp+28h+arg_8]
PAGE:00000001405D3FF3 call    PspAllocStorage

  判断ejob->Storage如果为空则调用PspAllocStorage分配一个silo context。

PAGE:00000001405D4013 call    PspJobHasChildren
PAGE:00000001405D4018 test    al, al
PAGE:00000001405D401A jz      short loc_1405D4023
PAGE:00000001405D401C mov     esi, 0C000050Fh

  如果job存在子进程，设置esi为0C000050Fh。

PAGE:00000001405D4023 loc_1405D4023: ; CODE XREF: PspCreateSilo+6E↑j
PAGE:00000001405D4023 mov     edx, 40000000h
PAGE:00000001405D4028 test    [rbx+528h], edx
PAGE:00000001405D402E jz      short loc_1405D4037
PAGE:00000001405D4030 mov     esi, 0C0000508h

  如果ejob->Silo == 1，设置esi为0C0000508h。

PAGE:00000001405D404A loc_1405D404A: ; CODE XREF: PspCreateSilo+95↑j
PAGE:00000001405D404A xor     eax, eax
PAGE:00000001405D404C lock cmpxchg [rbx+518h], rdi

  将当前ejob->Storage值与PspAllocStorage分配的地址互换。

  接着看下PspAllocStorage的实现：

PAGE:000000014064EF40 ; __int64 __fastcall PspAllocStorage(_QWORD *)
PAGE:000000014064EF40 PspAllocStorage proc near
PAGE:000000014064EF46 mov     edx, 240h       ; NumberOfBytes
PAGE:000000014064EF4B mov     rbx, rcx
PAGE:000000014064EF4E mov     r8d, 74537350h  ; Tag
PAGE:000000014064EF54 lea     ecx, [rdx-3Ch]  ; PoolType
PAGE:000000014064EF57 call    ExAllocatePoolWithTag

  微软符号表中并没有给出_PSP_STORAGE结构体的定义。

lkd> dt nt!_PSP_STORAGE
Symbol nt!_PSP_STORAGE not found.

  但是根据传递给ExAllocatePoolWithTag函数的第二个参数为240h，所以可以断定_PSP_STORAGE结构体大小为240h。

PAGE:000000014064EF67 lea     ecx, [r8+20h]
PAGE:000000014064EF6B
PAGE:000000014064EF6B loc_14064EF6B: ; CODE XREF: PspAllocStorage+3A↓j
PAGE:000000014064EF6B mov     [rax], r8
PAGE:000000014064EF6E mov     [rax+8], r8
PAGE:000000014064EF72 lea     rax, [rax+10h]
PAGE:000000014064EF76 sub     rcx, 1
PAGE:000000014064EF7A jnz     short loc_14064EF6B
PAGE:000000014064EF7C mov     [rdx+200h], r8

  ecx设置为32，将storage地址依次设为0，可以试着组建一下_PSP_STORAGE结构体：

struct _PSP_STORAGE {
slot_type slots[32];
...
}
struct slot_type {
void *ptr1;
void *ptr2;
}

2.3.2 PspSetJobSiloThreadImpersonationPolicy

  启用或关闭silo，它有两个参数第一个为ejob结构，第2个为silo的状态值。

AGE:0000000140909864 PspSetJobSiloThreadImpersonationPolicy proc near
PAGE:0000000140909864 mov     eax, 2
PAGE:0000000140909869 mov     r9, rcx
PAGE:000000014090986C cmp     edx, eax
PAGE:000000014090986E lea     r8d, [rax+2]
PAGE:0000000140909872 cmovnz  r8d, eax
PAGE:0000000140909876 mov     eax, [rcx+52Ch]
PAGE:000000014090987C test    edx, eax
PAGE:000000014090987E jz      short loc_140909895
PAGE:0000000140909880
PAGE:0000000140909880 loc_140909880: PAGE:0000000140909880                 mov     al, 1
PAGE:0000000140909882 retn

 如果第二个参数不为2，强行设为2，如果ejob->EnableUsermodeSiloThreadImpersonation已经置位则返回。

PAGE:0000000140909884
PAGE:0000000140909884 loc_140909884:
PAGE:0000000140909884 mov     ecx, eax
PAGE:0000000140909886 or      ecx, edx
PAGE:0000000140909888 lock cmpxchg [r9+52Ch], ecx
PAGE:0000000140909891 cmp     eax, ecx
PAGE:0000000140909893 jz      short loc_140909880
PAGE:0000000140909895
PAGE:0000000140909895 loc_140909895: ; CODE XREF: PspSetJobSiloThreadImpersonationPolicy+1A↑j
PAGE:0000000140909895 test    eax, r8d
PAGE:0000000140909898 jz      short loc_140909884
PAGE:000000014090989A xor     al, al
PAGE:000000014090989C retn

  设置ejob->EnableUsermodeSiloThreadImpersonation |= 2。

2.3.3 ObInitServerSilo

PAGE:00000001407C0E70 ; NTSTATUS __fastcall ObInitServerSilo(__int64)
PAGE:00000001407C0E70 ObInitServerSilo proc near
PAGE:00000001407C0E9D and     qword ptr [rax+78h], 0 ; _ESERVERSILO_GLOBALS->ObSiloState->DeviceMapLock = 0
PAGE:00000001407C0EA2 lea     rdx, [rax+80h]  ; _ESERVERSILO_GLOBALS->ObSiloState->PrivateNamespaceLookupTable
PAGE:00000001407C0EA9 and     qword ptr [rdx+250h], 0 ; _ESERVERSILO_GLOBALS->ObSiloState->PrivateNamespaceLookupTable->Lock = 0
PAGE:00000001407C0EB1 mov     eax, 25h ; '%'
PAGE:00000001407C0EB6
PAGE:00000001407C0EB6 loc_1407C0EB6: ; CODE XREF: ObInitServerSilo+55↓j
PAGE:00000001407C0EB6 mov     [rdx+8], rdx
PAGE:00000001407C0EBA mov     [rdx], rdx
PAGE:00000001407C0EBD add     rdx, 10h
PAGE:00000001407C0EC1 sub     rax, 1
PAGE:00000001407C0EC5 jnz     short loc_1407C0EB6
PAGE:00000001407C0EC7 call    PsIsHostSilo
PAGE:00000001407C0ECC test    al, al
PAGE:00000001407C0ECE jz      loc_14085E746

  初始化ejob->ObSiloState结构，ObSiloState->PrivateNamespaceLookupTable是一个哈希表，每个项是一个双向链表节点，blink,flink都指向自己。

PAGE:000000014085E753 call    PsGetPermanentSiloContext

    ejob->0x518地址保存silo context。

2.3.4 PspInitializeProtectedProcessParameters

  设置进程的enviorment内容

PAGE:00000001407BC430 ; __int64 __fastcall PspInitializeProtectedProcessParameters(__int64)
PAGE:00000001407BC430 PspInitializeProtectedProcessParameters proc near
PAGE:00000001407BC44F movdqu  xmmword ptr [rcx+3E8h], xmm0 ; _ESERVERSILO_GLOBALS->PsProtectedCurrentDirectory = _ESERVERSILO_GLOBALS->NtSystemRoot
PAGE:00000001407BC457 movzx   eax, word ptr [rcx+430h]

  首先设置_ESERVERSILO_GLOBALS->PsProtectedCurrentDirectory

PAGE:00000001407BC457 movzx   eax, word ptr [rcx+430h]
PAGE:00000001407BC45E movups  xmm1, xmmword ptr [rcx+430h]
PAGE:00000001407BC465 add     ax, 2Ah ; '*'
PAGE:00000001407BC469 add     ax, ax
PAGE:00000001407BC46C mov     [rcx+3F8h], ax  ; PsProtectedEnvironment = (NtSystemRoot + 0x2a) * 2
PAGE:00000001407BC473 add     ax, 2
PAGE:00000001407BC477 movzx   edx, ax         ; NumberOfBytes
PAGE:00000001407BC47A mov     [rcx+3FAh], dx
PAGE:00000001407BC481 mov     ecx, 1          ; PoolType
PAGE:00000001407BC486 movdqu  [rsp+38h+var_18], xmm1
PAGE:00000001407BC48C call    ExAllocatePoolWithTag ; (1, NumberOfBytes)
PAGE:00000001407BC491 xor     esi, esi
PAGE:00000001407BC493 mov     [rdi+400h], rax ; PsProtectedEnvironment + 8
PAGE:00000001407BC49A mov     rbx, rax
PAGE:00000001407BC49D test    rax, rax
PAGE:00000001407BC4A0 jz      loc_14085D110
PAGE:00000001407BC4A6 mov     rax, cs:off_140983D28 ; "Path="
PAGE:00000001407BC4AD movsd   xmm0, qword ptr [rax]
PAGE:00000001407BC4B1 movsd   qword ptr [rbx], xmm0
PAGE:00000001407BC4B5 movzx   eax, word ptr [rax+8]
PAGE:00000001407BC4B9 mov     [rbx+8], ax
PAGE:00000001407BC4BD add     rbx, 0Ah
PAGE:00000001407BC4C1 movzx   r8d, word ptr [rdi+430h] ; Size
PAGE:00000001407BC4C9 mov     rcx, rbx        ; void *
PAGE:00000001407BC4CC mov     rdx, [rdi+438h] ; Src
PAGE:00000001407BC4D3 call    memmove         ; Path=NtSystemRoot+8
PAGE:00000001407BC4D8 mov     rax, cs:off_140983D18 ; "\\System32"
PAGE:00000001407BC4DF movzx   edx, word ptr [rdi+430h] ; NtSystemRoot->Length
PAGE:00000001407BC4E6 movups  xmm0, xmmword ptr [rax]
PAGE:00000001407BC4E9 movups  xmmword ptr [rdx+rbx], xmm0
PAGE:00000001407BC4ED movzx   eax, word ptr [rax+10h]
PAGE:00000001407BC4F1 mov     [rdx+rbx+10h], ax
PAGE:00000001407BC4F6 mov     [rdx+rbx+12h], si
PAGE:00000001407BC4FB mov     rax, cs:off_140983D38 ; "SystemDrive="
PAGE:00000001407BC502 movups  xmm0, xmmword ptr [rax]
PAGE:00000001407BC505 movups  xmmword ptr [rdx+rbx+14h], xmm0
PAGE:00000001407BC50A movsd   xmm1, qword ptr [rax+10h]
PAGE:00000001407BC50F mov     rax, qword ptr [rsp+38h+var_18+8] ; NtSystemRoot->Buffer
PAGE:00000001407BC514 movsd   qword ptr [rdx+rbx+24h], xmm1
PAGE:00000001407BC51A mov     ecx, [rax]
PAGE:00000001407BC51C mov     [rdx+rbx+2Ch], ecx
PAGE:00000001407BC520 mov     [rdx+rbx+30h], si
PAGE:00000001407BC525 mov     rcx, cs:off_140983D48 ; "SystemRoot="
PAGE:00000001407BC52C movups  xmm0, xmmword ptr [rcx]
PAGE:00000001407BC52F movups  xmmword ptr [rdx+rbx+32h], xmm0
PAGE:00000001407BC534 mov     eax, [rcx+10h]
PAGE:00000001407BC537 mov     [rdx+rbx+42h], eax
PAGE:00000001407BC53B movzx   eax, word ptr [rcx+14h]
PAGE:00000001407BC53F mov     [rdx+rbx+46h], ax
PAGE:00000001407BC544 add     rbx, rdx
PAGE:00000001407BC547 movzx   r8d, word ptr [rdi+430h] ; Size
PAGE:00000001407BC54F mov     rdx, [rdi+438h] ; Src
PAGE:00000001407BC556 lea     rcx, [rbx+48h]  ; void *
PAGE:00000001407BC55A call    memmove         ; NtSystemRoot

  构造PsProtectedEnvironment内容：

+-------------------------------------------------------------------------------------------------------------------+

| Path= | NtSystemRoot->Buffer| \\System32 | SystemDrive= | NtSystemRoot->Buffer[0]|SystemRoot=|NtSystemRoot->Buffer |

+-------------------------------------------------------------------------------------------------------------------+

  一共3个环境变量： Path、SystemDrive、SystemRoot

2.3.5 PspSiloInitializeSystemRootSymlink

PAGE:0000000140906AF0 ; NTSTATUS __fastcall PspSiloInitializeSystemRootSymlink(_LIST_ENTRY *)
PAGE:0000000140906AF0 PspSiloInitializeSystemRootSymlink proc nea
PAGE:0000000140906B8F call    RtlAppendUnicodeStringToString ; \\GLOBAL??\\ + _ESERVERSILO_GLOBALS->NtSystemRoot
PAGE:0000000140906B94 lea     rax, PspSystemRootSymlinkName ; \\SystemRoot
PAGE:0000000140906BC1 lea     r9, [rbp+DestinationString]
PAGE:0000000140906BC5 mov     edx, 0F0001h
PAGE:0000000140906BCA lea     r8, [rbp+var_30]
PAGE:0000000140906BCE mov     rbx, rax
PAGE:0000000140906BD1 lea     rcx, [rbp+Handle]
PAGE:0000000140906BD5 call    ZwCreateSymbolicLinkObject

  调用未公开接口ZwCreateSymbolicLinkObject建立\\SystemRoot到\\GLOBAL??\\ + _ESERVERSILO_GLOBALS->NtSystemRoot的软链接？

2.3.6  PspSiloInitializeUserSharedData

PAGE:0000000140906C1C ; __int64 __fastcall PspSiloInitializeUserSharedData(_LIST_ENTRY *)
PAGE:0000000140906C1C PspSiloInitializeUserSharedData proc near
PAGE:0000000140906CB3 mov     [rax+468h], rcx ; _ESERVERSILO_GLOBALS->serSharedData = MappedBase
PAGE:0000000140906CBA mov     rcx, rsi
PAGE:0000000140906CBD mov     [rax+470h], rbx ; _ESERVERSILO_GLOBALS->UserSharedSection = Section

  设置silo的serSharedData和UserSharedSection字段。

2.3.7 PspSiloInitializeLicenseData

PspSiloInitializeLicenseData函数初始化silo的License Data

.text:00000001405B03A8 ; __int64 __fastcall PspSiloInitializeLicenseData(_LIST_ENTRY *)
.text:00000001405B03A8 PspSiloInitializeLicenseData proc near
.text:00000001405B0406 mov     edx, 0B7C0h
.text:00000001405B040B mov     ecx, 100h
.text:00000001405B0410 mov     r8d, 69534C53h
.text:00000001405B0416 call    ExAllocatePool2 ; struct _EXP_LICENSE_STATE

  分配struct _EXP_LICENSE_STATE结构体，微软符号表中未提供它的数据结构。

.text:00000001405B049F mov     [rbx+388h], rsi ; ejob->ExpLicenseState
.text:00000001405B04A6 mov     [rbp+57h+var_68], 100h
.text:00000001405B04AD mov     [rbp+57h+var_50], 3000003h
.text:00000001405B04B4 mov     [rbp+57h+var_40], 14000h
.text:00000001405B04BB mov     [rbp+57h+var_58], rsi
.text:00000001405B04BF call    ExpInitLicensing

    ExpInitLicensing 做简单初始化，如果是全局silo变量PspHostSiloGlobals，使用ExpHostBootLicensingData作为默认的license data。

.text:00000001405B04D7 lea     rdx, aProductoptions_0 ; "ProductOptions"
.text:00000001405B04DE xor     r9d, r9d
.text:00000001405B04E1 mov     rbx, [rcx+608h]
.text:00000001405B04E8 mov     [rcx+608h], rdi
.text:00000001405B04EF lea     ecx, [r9+2]
.text:00000001405B04F3 call    RtlQueryRegistryValuesEx ; (gs:188h, "ProductOptions", ExpQueryRegistryRoutine, 0)
.text:00000001405B04F8 mov     edi, eax
.text:00000001405B04FA call    ExInitLicenseData

  查询注册表ProductOptions键值，ExpQueryRegistryRoutine为回调函数。

      ExInitLicenseData初始化license的关键函数，过于复杂，未跟踪。

2.4 Namespace隔离

2.4.1 注册表隔离

  每个silo进程都有独立的注册表namespace。

PAGE:000000014068B2E0 CmpParseKey proc near
PAGE:000000014068B689 mov     rcx, [r13+8]
PAGE:000000014068B68D call    CmpGetRegistryNamespaceRootForSilo

   CmpGetRegistryNamespaceRootForSilo调用PsGetPermanentSiloContext获取ejob->Storage的地址。

PAGE:0000000140687B1F mov     rax, [rax+20h]

    ejob->Storage.slots[32]为vreg namespace的地址。

2.4.2 进程隔离

PAGE:00000001406746A0 ; NTSTATUS __stdcall PsLookupThreadByThreadId(HANDLE ThreadId, PETHREAD *Thread)
PAGE:00000001406746A0 public PsLookupThreadByThreadId
PAGE:00000001406746A0 PsLookupThreadByThreadId proc near
PAGE:00000001406746B5 mov     rsi, gs:188h    ; CurrentThread
PAGE:00000001406746BE mov     r14, rdx
PAGE:00000001406746C1 dec     word ptr [rsi+1E6h] ; --CurrentThread->SpecialApcDisable
PAGE:00000001406746C8 mov     dl, 6
PAGE:00000001406746CA call    PspReferenceCidTableEntry ; (ThreadId, 6)

    PspReferenceCidTableEntry函数根据ThreadId返回对应的ethread结构体。

PAGE:00000001406746D7 call    PsGetCurrentServerSilo

  得到当前进程的ejob结构体。

PAGE:000000014067470D loc_14067470D: ; CODE XREF: PsLookupThreadByThreadId+48↑j
PAGE:000000014067470D mov     rcx, [rbx+220h] ; (kproces *)thread->tcb->process
PAGE:0000000140674714 mov     rdx, rdi
PAGE:0000000140674717 call    PsIsProcessInSilo ; (kprocess, ejob)
PAGE:000000014067471C test    al, al
PAGE:000000014067471E jnz     short loc_14067472A
PAGE:0000000140674720
PAGE:0000000140674720 loc_140674720: ; CODE XREF: PsLookupThreadByThreadId+6B↑j
PAGE:0000000140674720 mov     rcx, rbx        ; DmaAdapter
PAGE:0000000140674723 call    HalPutDmaAdapter
PAGE:0000000140674728 xor     ebx, ebx

    PsIsProcessInSilo函数有两个参数，第一个参数为要得到handle的目标进程kprocess结构体， 第二个参数为当前进程的ejob结构体，如果返回值为0就不能获取目标进程的Handle，为1则可以。

下面仔细分析下这个函数：

.text:0000000140273948 PsIsProcessInSilo proc near ; CODE XREF: PsIsThreadInSilo+29↑p
.text:0000000140273948 ; PsLookupThreadByThreadId+77↓p ...
.text:0000000140273948 sub     rsp, 28h
.text:000000014027394C test    rdx, rdx
.text:000000014027394F jnz     short loc_140273959
.text:0000000140273951
.text:0000000140273951 loc_140273951: ; CODE XREF: PsIsProcessInSilo+18↓j
.text:0000000140273951 ; PsIsProcessInSilo+21↓j
.text:0000000140273951 mov     al, 1           ; ejob == NULL
.text:0000000140273953
.text:0000000140273953 loc_140273953: ; CODE XREF: PsIsProcessInSilo+3C↓j
.text:0000000140273953 add     rsp, 28h
.text:0000000140273957 retn

  如果第二个参数ejob为空则返回1。

.text:0000000140273959
.text:0000000140273959 loc_140273959: ; CODE XREF: PsIsProcessInSilo+7↑j
.text:0000000140273959 cmp     rcx, cs:PsInitialSystemProcess
.text:0000000140273960 jz      short loc_140273951 ; ejob == NULL
.text:0000000140273962 cmp     rcx, cs:PsIdleProcess
.text:0000000140273969 jz      short loc_140273951 ; ejob == NULL

  如果第一个参数kprocess为PsInitialSystemProcess或PsIdleProcess同样返回为1。

.text:000000014027396B mov     rcx, [rcx+510h] ; eprocess->job
.text:0000000140273972 call    PspGetJobSilo

    PspGetJobSilo函数从当前进程的ejob开始向父进程ejob查找到第一个包含silo状态的ejob结构体。

.text:0000000140273977 mov     rcx, rax
.text:000000014027397A call    PspIsSiloInSilo
.text:000000014027397F test    al, al
.text:0000000140273981 setnz   al
.text:0000000140273984 jmp     short loc_140273953
.text:0000000140273984 PsIsProcessInSilo endp

    PspIsSiloInSilo函数包含两个参数，第一个参数为目标进程包含silo状态的ejob结构体，第二个参数为当前进程的ejob结构体。如果返回值不为0，则返回1。

PAGE:000000014064BB6C PspIsSiloInSilo proc near ; CODE XREF: PsIsProcessInSilo+32↑p
PAGE:000000014064BB6C ; PsIsThreadInSilo+1EA483↑p ...
PAGE:000000014064BB6C test    rdx, rdx
PAGE:000000014064BB6F jnz     short loc_14064BB75
PAGE:000000014064BB71
PAGE:000000014064BB71 loc_14064BB71: ; CODE XREF: PspIsSiloInSilo+1BA6A7↓j
PAGE:000000014064BB71 mov     al, 1
PAGE:000000014064BB73 retn

  如果第二个参数ejob为0，则返回1。

PAGE:000000014064BB75 loc_14064BB75: ; CODE XREF: PspIsSiloInSilo+3↑j
PAGE:000000014064BB75 ; PspIsSiloInSilo+1BA6B4↓j
PAGE:000000014064BB75 test    rcx, rcx
PAGE:000000014064BB78 jnz     loc_140806210
PAGE:000000014064BB7E xor     al, al
PAGE:000000014064BB80 retn
PAGE:0000000140806210 loc_140806210: ; CODE XREF: PspIsSiloInSilo+C↑j
PAGE:0000000140806210 cmp     rcx, rdx
PAGE:0000000140806213 jz      loc_14064BB71
PAGE:0000000140806219 mov     rcx, [rcx+430h]
PAGE:0000000140806220 jmp     loc_14064BB75

  通过一个循环遍历第一个参数及它的父进程ejob是否和第二个参数相等，如果相等返回1，否则返回0。所以通过上述两个函数的分析，一个进程能否获取另一个进程的handle，有以下几种情况：

1、如果当前进程没有silo结构，也就是说当前进程在容器外，是可以得到容器内进程的handle。

2、PsInitialSystemProcess和PsIdleProcess进程能获取任何容器内进程的handle。

3、容器内的进程是不能获取容器外的任何进程handle。

4、只有父亲容器可以获取子容器内进程的handle，反之不可以。

2.4.3 驱动隔离

    silo进程内不能安装和卸载驱动程序。

.text:0000000140399388 ; __int64 __fastcall IopLoadDriverImage(_OWORD *)
.text:0000000140399388 IopLoadDriverImage proc near ; CODE XREF: NtLoadDriver+4↓p
.text:0000000140399388
.text:00000001403993EE call    PsIsCurrentThreadInServerSilo
.text:00000001403993F3 test    al, al
.text:00000001403993F5 jnz     loc_140399568

  如果进程在container内是不允许加载驱动程序的。

PAGE:0000000140762F24 IopUnloadDriver proc near ; CODE XREF: PnpUnloadAttachedDriver+A1↑p
PAGE:0000000140762F24
PAGE:0000000140762FA2 call    PsIsCurrentThreadInServerSilo
PAGE:0000000140762FA7 test    al, al
PAGE:0000000140762FA9 jnz     loc_14081B8E9

  同理，contianer进程不能卸载驱动程序。

2.4.4 文件隔离

AGE:000000014068F290 ObpLookupObjectName proc near ; CODE XREF: ObReferenceObjectByNameEx+156↑p
PAGE:000000014068F290
PAGE:000000014068F4C6 mov     edx, cs:PsObjectDirectorySiloContextSlot
PAGE:000000014068F4CC mov     [rbp+0C0h+var_D0], r8
PAGE:000000014068F4D0 lea     r8, [rbp+0C0h+var_D0]
PAGE:000000014068F4D4 call    PsGetPermanentSiloContext
PAGE:000000014068F4D9 test    eax, eax
PAGE:000000014068F4DB jns     loc_140835AE0
PAGE:000000014068F4E1 mov     r14, cs:ObpRootDirectoryObject

  如果在容器中则通过PsGetPermanentSiloContext获取root directory， 否则使用ObpRootDirectoryObject作为root directory。

.text:00000001402772A0 PsGetPermanentSiloContext proc near ; CODE XREF: CmGetRootKeyObjectForSilo+17↓p
.text:00000001402772A0 test    rcx, rcx
.text:00000001402772A3 jnz     short loc_1402772DB
.text:00000001402772A5 mov     rcx, cs:qword_140D23990
.text:00000001402772AC
.text:00000001402772AC loc_1402772AC: ; CODE XREF: PsGetPermanentSiloContext+42↓j
.text:00000001402772AC mov     qword ptr [r8], 0
.text:00000001402772B3 cmp     edx, 20h ; ' '
.text:00000001402772B6 jnb     loc_14041937E
.text:00000001402772BC
.text:00000001402772BC loc_1402772BC: ; CODE XREF: PsGetPermanentSiloContext+1A20F9↓j
.text:00000001402772BC mov     eax, edx
.text:00000001402772BE add     rax, rax
.text:00000001402772C1 mov     rcx, [rcx+rax*8+8]
.text:00000001402772C6 mov     rax, rcx
.text:00000001402772C9 and     rax, 0FFFFFFFFFFFFFFFEh
.text:00000001402772CD jz      short loc_1402772E4
.text:00000001402772CF test    cl, 1
.text:00000001402772D2 jz      short loc_1402772EB
.text:00000001402772D4 mov     [r8], rax
.text:00000001402772D7 xor     eax, eax
.text:00000001402772D9 retn
.text:00000001402772D9 ; ---------------------------------------------------------------------------
.text:00000001402772DA db 0CCh
.text:00000001402772DB ; ---------------------------------------------------------------------------
.text:00000001402772DB
.text:00000001402772DB loc_1402772DB: ; CODE XREF: PsGetPermanentSiloContext+3↑j
.text:00000001402772DB mov     rcx, [rcx+518h]
.text:00000001402772E2 jmp     short loc_1402772AC

    ejob->Storage[PsObjectDirectorySiloContextSlot].value为当前容器的root directory。

   OBP_GET_SILO_ROOT_DIRECTORY_FROM_SILO函数有同样的功能。


文章来源: https://mp.weixin.qq.com/s?__biz=Mzg4NjU1NDU4MA==&mid=2247483796&idx=1&sn=07e185a325441c0570b5996edc7d408d&chksm=cf96ab2ff8e12239aa10b49d5f166a4f375fadfd7cd1326eb410efca0978685f6e73679ff308&scene=58&subscene=0#rd
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