NTSTATUS
NtClose (
IN HANDLE Handle
)
/*++
Routine Description:
This function is used to close access to the specified handle
Arguments:
Handle - Supplies the handle being closed
Return Value:
An appropriate status value
--*/
{
PHANDLE_TABLE ObjectTable;
PHANDLE_TABLE_ENTRY ObjectTableEntry;
PVOID Object;
ULONG CapturedGrantedAccess;
ULONG CapturedAttributes;
POBJECT_HEADER ObjectHeader;
POBJECT_TYPE ObjectType;
NTSTATUS Status;
BOOLEAN AttachedToProcess = FALSE;
KAPC_STATE ApcState;
//
// Protect ourselves from being interrupted while we hold a handle table
// entry lock
//
KeEnterCriticalRegion();
try {
#if DBG
KIRQL SaveIrql;
#endif // DBG
ObpValidateIrql( "NtClose" );
ObpBeginTypeSpecificCallOut( SaveIrql );
#if DBG
//
// On checked builds, check that if the Kernel handle bit is set, then
// we're coming from Kernel mode. We should probably fail the call if
// bit set && !Kmode
//
if ((Handle != NtCurrentThread()) && (Handle != NtCurrentProcess())) {
ASSERT((Handle < 0 ) ? (KeGetPreviousMode() == KernelMode) : TRUE);
}
#endif
//
// For the current process we will grab its handle/object table and
// translate the handle to its corresponding table entry. If the
// call is successful it also lock down the handle table. But first
// check for a kernel handle and attach and use that table if so.
//
if (IsKernelHandle( Handle, KeGetPreviousMode() )) {
Handle = DecodeKernelHandle( Handle );
ObjectTable = ObpKernelHandleTable;
//
// Go to the system process if we have to
//
if (PsGetCurrentProcess() != PsInitialSystemProcess) {
KeStackAttachProcess (&PsInitialSystemProcess->Pcb, &ApcState);
AttachedToProcess = TRUE;
}
} else {
ObjectTable = ObpGetObjectTable();
}
ObjectTableEntry = ExMapHandleToPointer( ObjectTable,
Handle );
//
// Check that the specified handle is legitimate otherwise we can
// assume the caller just passed in some bogus handle value
//
if (ObjectTableEntry != NULL) {
//
// From the object table entry we can grab a pointer to the object
// header, get its type and its body
//
ObjectHeader = (POBJECT_HEADER)(((ULONG_PTR)(ObjectTableEntry->Object)) & ~OBJ_HANDLE_ATTRIBUTES);
ObjectType = ObjectHeader->Type;
Object = &ObjectHeader->Body;
//
// If the object type specifies an okay to close procedure then we
// need to invoke that callback. If the callback doesn't want us to
// close handle then unlock the object table and return the error
// to our caller
//
if (ObjectType->TypeInfo.OkayToCloseProcedure != NULL) {
if (!(*ObjectType->TypeInfo.OkayToCloseProcedure)( PsGetCurrentProcess(), Object, Handle )) {
ObpEndTypeSpecificCallOut( SaveIrql, "NtClose", ObjectType, Object );
ExUnlockHandleTableEntry( ObjectTable, ObjectTableEntry );
//
// If we are attached to the system process then return
// back to our caller
//
if (AttachedToProcess) {
KeUnstackDetachProcess(&ApcState);
AttachedToProcess = FALSE;
}
Status = STATUS_HANDLE_NOT_CLOSABLE;
leave;
}
}
CapturedAttributes = ObjectTableEntry->ObAttributes;
//
// If the previous mode was user and the handle is protected from
// being closed, then we'll either raise or return an error depending
// on the global flags and debugger port situation.
//
if ((CapturedAttributes & OBJ_PROTECT_CLOSE) != 0) {
if (KeGetPreviousMode() != KernelMode) {
ExUnlockHandleTableEntry( ObjectTable, ObjectTableEntry );
if ((NtGlobalFlag & FLG_ENABLE_CLOSE_EXCEPTIONS) ||
(PsGetCurrentProcess()->DebugPort != NULL)) {
//
// If we are attached to the system process then return
// back to our caller
//
if (AttachedToProcess) {
KeUnstackDetachProcess(&ApcState);
AttachedToProcess = FALSE;
}
Status = KeRaiseUserException(STATUS_HANDLE_NOT_CLOSABLE);
leave;
} else {
//
// If we are attached to the system process then return
// back to our caller
//
if (AttachedToProcess) {
KeUnstackDetachProcess(&ApcState);
AttachedToProcess = FALSE;
}
Status = STATUS_HANDLE_NOT_CLOSABLE;
leave;
}
} else {
if ((!PsIsThreadTerminating(PsGetCurrentThread())) &&
(PsGetCurrentProcess()->Peb != NULL)) {
ExUnlockHandleTableEntry( ObjectTable, ObjectTableEntry );
#if DBG
//
// bugcheck here on checked builds if kernel mode code is
// closing a protected handle and process is not exiting.
// Ignore if no PEB as this occurs if process is killed
// before really starting.
//
KeBugCheckEx(INVALID_KERNEL_HANDLE, (ULONG_PTR)Handle, 0, 0, 0);
#else
//
// If we are attached to the system process then return
// back to our caller
//
if (AttachedToProcess) {
KeUnstackDetachProcess(&ApcState);
AttachedToProcess = FALSE;
}
Status = STATUS_HANDLE_NOT_CLOSABLE;
leave;
#endif // DBG
}
}
}
//
// Get the granted access for the handle
//
#if defined(_X86_) && !FPO
if (NtGlobalFlag & FLG_KERNEL_STACK_TRACE_DB) {
CapturedGrantedAccess = ObpTranslateGrantedAccessIndex( ObjectTableEntry->GrantedAccessIndex );
} else {
CapturedGrantedAccess = ObjectTableEntry->GrantedAccess;
}
#else
CapturedGrantedAccess = ObjectTableEntry->GrantedAccess;
#endif // _X86_ && !FPO
//
// Now remove the handle from the handle table
//
ExDestroyHandle( ObjectTable,
Handle,
ObjectTableEntry );
//
// perform any auditing required
//
//
// Extract the value of the GenerateOnClose bit stored
// after object open auditing is performed. This value
// was stored by a call to ObSetGenerateOnClosed.
//
if (CapturedAttributes & OBJ_AUDIT_OBJECT_CLOSE) {
if ( SepAdtAuditingEnabled ) {
SeCloseObjectAuditAlarm( Object,
(HANDLE)((ULONG_PTR)Handle & ~OBJ_HANDLE_TAGBITS), // Mask off the tagbits defined for OB objects.
TRUE );
}
}
//
// Since we took the handle away we need to decrement the objects
// handle count, and remove a reference
//
ObpDecrementHandleCount( PsGetCurrentProcess(),
ObjectHeader,
ObjectHeader->Type,
CapturedGrantedAccess );
ObDereferenceObject( Object );
ObpEndTypeSpecificCallOut( SaveIrql, "NtClose", ObjectType, Object );
//
// If we are attached to the system process then return
// back to our caller
//
if (AttachedToProcess) {
KeUnstackDetachProcess(&ApcState);
AttachedToProcess = FALSE;
}
//
// And return to our caller
//
Status = STATUS_SUCCESS;
leave;
} else {
//
// At this point the input handle did not translate to a valid
// object table entry
//
ObpEndTypeSpecificCallOut( SaveIrql, "NtClose", ObpTypeObjectType, Handle );
//
// If we are attached to the system process then return
// back to our caller
//
if (AttachedToProcess) {
KeUnstackDetachProcess(&ApcState);
AttachedToProcess = FALSE;
}
//
// Now if the handle is not null and it does not represent the
// current thread or process then if we're user mode we either raise
// or return an error
//
if ((Handle != NULL) &&
(Handle != NtCurrentThread()) &&
(Handle != NtCurrentProcess())) {
if (KeGetPreviousMode() != KernelMode) {
if ((NtGlobalFlag & FLG_ENABLE_CLOSE_EXCEPTIONS) ||
(PsGetCurrentProcess()->DebugPort != NULL)) {
Status = KeRaiseUserException(STATUS_INVALID_HANDLE);
leave;
} else {
Status = STATUS_INVALID_HANDLE;
leave;
}
} else {
//
// bugcheck here if kernel debugger is enabled and if kernel mode code is
// closing a bogus handle and process is not exiting. Ignore
// if no PEB as this occurs if process is killed before
// really starting.
//
if (( !PsIsThreadTerminating(PsGetCurrentThread())) &&
(PsGetCurrentProcess()->Peb != NULL)) {
if (KdDebuggerEnabled) {
KeBugCheckEx(INVALID_KERNEL_HANDLE, (ULONG_PTR)Handle, 1, 0, 0);
}
}
}
}
Status = STATUS_INVALID_HANDLE;
leave;
}
} finally {
KeLeaveCriticalRegion();
}
return Status;
}
VOID
ObKillProcess(
BOOLEAN AcquireLock,
PEPROCESS Process
)
/*++
Routine Description:
This function is called whenever a process is destroyed. It loops over
the process' object table and closes all the handles.
Arguments:
AcquireLock - TRUE if there are other pointers to this process and therefore
this operation needs to be synchronized. False if this is being called
from the Process delete routine and therefore this is the only pointer
to the process.
Process - Pointer to the process that is being destroyed.
Return Value:
None.
--*/
{
PVOID ObjectTable;
PAGED_CODE();
ObpValidateIrql( "ObKillProcess" );
if (AcquireLock) {
KeWaitForSingleObject( &ObpInitKillMutant,
Executive,
KernelMode,
FALSE,
NULL
);
}
//
// If the process does NOT have an object table, return
//
ObjectTable = Process->ObjectTable;
if (ObjectTable != NULL) {
//
// For each valid entry in the object table, close the handle
// that points to that entry.
//
ExDestroyHandleTable( ObjectTable, ObDestroyHandleProcedure );
Process->ObjectTable = NULL;
}
if (AcquireLock) {
KeReleaseMutant( &ObpInitKillMutant, 0, FALSE, FALSE );
}
return;
}
NTSTATUS
ObInsertObject (
__in PVOID Object,
__in_opt PACCESS_STATE AccessState,
__in_opt ACCESS_MASK DesiredAccess,
__in ULONG ObjectPointerBias,
__out_opt PVOID *NewObject,
__out_opt PHANDLE Handle
)
/*++
Routine Description:
This routine inserts an object into the current processes handle table.
The Object header includes a pointer to a SecurityDescriptor passed in
an object creation call. This SecurityDescriptor is not assumed to have
been captured. This routine is responsible for making an appropriate
SecurityDescriptor and removing the reference in the object header.
Arguments:
Object - Supplies a pointer to the new object body
AccessState - Optionally supplies the access state for the new
handle
DesiredAccess - Optionally supplies the desired access we want for the
new handle
ObjectPointerBias - Supplies a bias to apply for the pointer count for the
object
NewObject - Optionally receives the pointer to the new object that we've
created a handle for
Handle - Receives the new handle, If NULL then no handle is created.
Objects that don't have handles created must be unnamed and
have an object bias of zero.
Return Value:
An appropriate NTSTATUS value.
--*/
{
POBJECT_CREATE_INFORMATION ObjectCreateInfo;
POBJECT_HEADER ObjectHeader;
PUNICODE_STRING ObjectName;
POBJECT_TYPE ObjectType;
POBJECT_HEADER_NAME_INFO NameInfo;
PSECURITY_DESCRIPTOR ParentDescriptor = NULL;
PVOID InsertObject;
HANDLE NewHandle;
OB_OPEN_REASON OpenReason;
NTSTATUS Status = STATUS_SUCCESS;
ACCESS_STATE LocalAccessState;
AUX_ACCESS_DATA AuxData;
BOOLEAN SecurityDescriptorAllocated;
KPROCESSOR_MODE PreviousMode;
NTSTATUS ReturnStatus;
PVOID DirObject = NULL;
OBP_LOOKUP_CONTEXT LookupContext;
PAGED_CODE();
ObpValidateIrql("ObInsertObject");
//
// Get the address of the object header, the object create information,
// the object type, and the address of the object name descriptor, if
// specified.
//
ObjectHeader = OBJECT_TO_OBJECT_HEADER(Object);
#if DBG
if ((ObjectHeader->Flags & OB_FLAG_NEW_OBJECT) == 0) {
KdPrint(("OB: Attempting to insert existing object %08x\n", Object));
KdBreakPoint();
ObDereferenceObject(Object);
return STATUS_INVALID_PARAMETER;
}
#endif
ObjectCreateInfo = ObjectHeader->ObjectCreateInfo;
ObjectType = ObjectHeader->Type;
NameInfo = ObpReferenceNameInfo( ObjectHeader );
ObjectName = NULL;
if ((NameInfo != NULL) && (NameInfo->Name.Buffer != NULL)) {
ObjectName = &NameInfo->Name;
}
ASSERT (ARGUMENT_PRESENT (Handle) || (ObjectPointerBias == 0 && ObjectName == NULL &&
ObjectType->TypeInfo.SecurityRequired && NewObject == NULL));
//
// If security checks are not required and an object name is not
// specified, insert an unnamed object, biasing the count
// by one, dereference the bias, and return to our caller
//
PreviousMode = KeGetPreviousMode();
if (!ObjectType->TypeInfo.SecurityRequired && (ObjectName == NULL)) {
ObjectHeader->ObjectCreateInfo = NULL;
*Handle = NULL;
Status = ObpCreateUnnamedHandle( Object,
DesiredAccess,
1 + ObjectPointerBias,
ObjectCreateInfo->Attributes,
PreviousMode,
NewObject,
Handle );
//
// Free the object creation information and dereference the object.
//
ObpFreeObjectCreateInformation(ObjectCreateInfo);
ObpDereferenceNameInfo( NameInfo );
ObDereferenceObject(Object);
return Status;
}
//
// The object is either named or requires full security checks. If the
// caller hasn't specified an access state then dummy up a local one
// using the requested desired access
//
if (!ARGUMENT_PRESENT(AccessState)) {
AccessState = &LocalAccessState;
Status = SeCreateAccessState( &LocalAccessState,
&AuxData,
DesiredAccess,
&ObjectType->TypeInfo.GenericMapping );
if (!NT_SUCCESS(Status)) {
ObpDereferenceNameInfo( NameInfo );
ObDereferenceObject(Object);
return Status;
}
}
AccessState->SecurityDescriptor = ObjectCreateInfo->SecurityDescriptor;
//
// Check the desired access mask against the security descriptor
//
Status = ObpValidateAccessMask( AccessState );
if (!NT_SUCCESS( Status )) {
if (AccessState == &LocalAccessState) {
SeDeleteAccessState( AccessState );
}
ObpDereferenceNameInfo( NameInfo );
ObDereferenceObject(Object);
if (AccessState == &LocalAccessState) {
SeDeleteAccessState( AccessState );
}
return( Status );
}
//
// Set some local state variables
//
ObpInitializeLookupContext(&LookupContext);
InsertObject = Object;
OpenReason = ObCreateHandle;
//
// Check if we have an object name. If so then
// lookup the name
//
if (ObjectName != NULL) {
Status = ObpLookupObjectName( ObjectCreateInfo->RootDirectory,
ObjectName,
ObjectCreateInfo->Attributes,
ObjectType,
(KPROCESSOR_MODE)(ObjectHeader->Flags & OB_FLAG_KERNEL_OBJECT
? KernelMode : UserMode),
ObjectCreateInfo->ParseContext,
ObjectCreateInfo->SecurityQos,
Object,
AccessState,
&LookupContext,
&InsertObject );
//
// We found the name and it is not the object we have as our input.
// So we cannot insert the object again so we'll return an
// appropriate status
//
if (NT_SUCCESS(Status) &&
(InsertObject != NULL) &&
(InsertObject != Object)) {
OpenReason = ObOpenHandle;
if (ObjectCreateInfo->Attributes & OBJ_OPENIF) {
if (ObjectType != OBJECT_TO_OBJECT_HEADER(InsertObject)->Type) {
Status = STATUS_OBJECT_TYPE_MISMATCH;
} else {
Status = STATUS_OBJECT_NAME_EXISTS; // Warning only
}
} else {
if (OBJECT_TO_OBJECT_HEADER(InsertObject)->Type == ObpSymbolicLinkObjectType) {
ObDereferenceObject(InsertObject);
}
Status = STATUS_OBJECT_NAME_COLLISION;
}
}
//
// We did not find the name so we'll cleanup after ourselves
// and return to our caller
//
if (!NT_SUCCESS( Status )) {
ObpReleaseLookupContext( &LookupContext );
ObpDereferenceNameInfo( NameInfo );
ObDereferenceObject( Object );
//
// Free security information if we allocated it
//
if (AccessState == &LocalAccessState) {
SeDeleteAccessState( AccessState );
}
return( Status );
} else {
//
// Otherwise we did locate the object name
//
// If we just created a named symbolic link then call out to
// handle any Dos Device name semantics.
//
if (ObjectType == ObpSymbolicLinkObjectType) {
ObpCreateSymbolicLinkName( (POBJECT_SYMBOLIC_LINK)InsertObject );
}
}
}
//
// If we are creating a new object, then we need assign security
// to it. A pointer to the captured caller-proposed security
// descriptor is contained in the AccessState structure. The
// SecurityDescriptor field in the object header must point to
// the final security descriptor, or to NULL if no security is
// to be assigned to the object.
//
if (InsertObject == Object) {
//
// Only the following objects have security descriptors:
//
// - Named Objects
// - Unnamed objects whose object-type information explicitly
// indicates a security descriptor is required.
//
if ((ObjectName != NULL) || ObjectType->TypeInfo.SecurityRequired) {
//
// Get the parent's descriptor, if there is one...
//
if ((NameInfo != NULL) && (NameInfo->Directory != NULL)) {
//
// This will allocate a block of memory and copy
// the parent's security descriptor into it, and
// return the pointer to the block.
//
// Call ObReleaseObjectSecurity to free up this
// memory.
//
ObGetObjectSecurity( NameInfo->Directory,
&ParentDescriptor,
&SecurityDescriptorAllocated );
}
else {
SecurityDescriptorAllocated = FALSE;
}
//
// Take the captured security descriptor in the AccessState,
// put it into the proper format, and call the object's
// security method to assign the new security descriptor to
// the new object.
//
Status = ObAssignSecurity( AccessState,
ParentDescriptor,
Object,
ObjectType );
if (ParentDescriptor != NULL) {
ObReleaseObjectSecurity( ParentDescriptor,
SecurityDescriptorAllocated );
} else if (NT_SUCCESS( Status )) {
SeReleaseSecurityDescriptor( ObjectCreateInfo->SecurityDescriptor,
ObjectCreateInfo->ProbeMode,
TRUE );
ObjectCreateInfo->SecurityDescriptor = NULL;
AccessState->SecurityDescriptor = NULL;
}
}
if (!NT_SUCCESS( Status )) {
//
// The attempt to assign the security descriptor to
// the object failed.
//
if (LookupContext.DirectoryLocked) {
//
// If ObpLookupObjectName already inserted the
// object into the directory we have to backup this
//
//
// Capture the object Directory
//
DirObject = NameInfo->Directory;
ObpDeleteDirectoryEntry( &LookupContext );
}
ObpReleaseLookupContext( &LookupContext );
//
// If ObpLookupObjectName inserted the object into the directory
// it added a reference to the object and to its directory
// object. We should remove the extra-references
//
if (DirObject) {
ObDereferenceObject( Object );
ObDereferenceObject( DirObject );
}
//
// The first backout logic used ObpDeleteNameCheck
// which is wrong because the security descriptor for
// the object is not initialized. Actually ObpDeleteNameCheck
// had no effect because the object was removed before from
// the directory
//
ObpDereferenceNameInfo( NameInfo );
ObDereferenceObject( Object );
//
// Free security information if we allocated it
//
if (AccessState == &LocalAccessState) {
SeDeleteAccessState( AccessState );
}
return( Status );
}
}
ReturnStatus = Status;
ObjectHeader->ObjectCreateInfo = NULL;
//
// Create a named handle for the object with a pointer bias
// This call also will unlock the directory lock is necessary
// on return
//
if (ARGUMENT_PRESENT (Handle)) {
Status = ObpCreateHandle( OpenReason,
InsertObject,
NULL,
AccessState,
1 + ObjectPointerBias,
ObjectCreateInfo->Attributes,
&LookupContext,
PreviousMode,
NewObject,
&NewHandle );
//
// If the insertion failed, the following dereference will cause
// the newly created object to be deallocated.
//
if (!NT_SUCCESS( Status )) {
//
// Make the name reference go away if an error.
//
if (ObjectName != NULL) {
ObpDeleteNameCheck( Object );
}
*Handle = NULL;
ReturnStatus = Status;
} else {
*Handle = NewHandle;
}
ObpDereferenceNameInfo( NameInfo );
ObDereferenceObject( Object );
} else {
BOOLEAN IsNewObject;
//
// Charge the user quota for the object.
//
ObpLockObject( ObjectHeader );
ReturnStatus = ObpChargeQuotaForObject( ObjectHeader, ObjectType, &IsNewObject );
ObpUnlockObject( ObjectHeader );
if (!NT_SUCCESS (ReturnStatus)) {
ObDereferenceObject( Object );
}
//
// N.B. An object cannot be named if no Handle parameter is specified.
// The calls to ObpDereferenceNameInfo and ObpReleaseLookupContext are
// not necessary in this path then.
//
}
ObpFreeObjectCreateInformation( ObjectCreateInfo );
//
// Free security information if we allocated it
//
if (AccessState == &LocalAccessState) {
SeDeleteAccessState( AccessState );
}
return( ReturnStatus );
}