ObReferenceObjectByHandle function (wdm.h)

Article
04/18/2022

The ObReferenceObjectByHandle routine provides access validation on the object handle, and, if access can be granted, returns the corresponding pointer to the object's body.

Syntax

NTSTATUS ObReferenceObjectByHandle(
  [in]            HANDLE                     Handle,
  [in]            ACCESS_MASK                DesiredAccess,
  [in, optional]  POBJECT_TYPE               ObjectType,
  [in]            KPROCESSOR_MODE            AccessMode,
  [out]           PVOID                      *Object,
  [out, optional] POBJECT_HANDLE_INFORMATION HandleInformation
);

Parameters

[in] Handle

Specifies an open handle for an object.

[in] DesiredAccess

Specifies the requested types of access to the object. The interpretation of this field is dependent on the object type. Do not use any generic access rights. For more information, see ACCESS_MASK.

[in, optional] ObjectType

Pointer to the object type. ObjectType can be *ExEventObjectType, *ExSemaphoreObjectType, *IoFileObjectType, *PsProcessType, *PsThreadType, *SeTokenObjectType, *TmEnlistmentObjectType, *TmResourceManagerObjectType, *TmTransactionManagerObjectType, or *TmTransactionObjectType.

If ObjectType is not NULL, the operating system verifies that the supplied object type matches the object type of the object that Handle specifies.

[in] AccessMode

Specifies the access mode to use for the access check. It must be either UserMode or KernelMode. Drivers should always specify UserMode for handles they receive from user address space.

[out] Object

Pointer to a variable that receives a pointer to the object's body. The following table contains the pointer types.

ObjectType parameter	Object pointer type
*ExEventObjectType	PKEVENT
*ExSemaphoreObjectType	PKSEMAPHORE
*IoFileObjectType	PFILE_OBJECT
*PsProcessType	PEPROCESS or PKPROCESS
*PsThreadType	PETHREAD or PKTHREAD
*SeTokenObjectType	PACCESS_TOKEN
*TmEnlistmentObjectType	PKENLISTMENT
*TmResourceManagerObjectType	PKRESOURCEMANAGER
*TmTransactionManagerObjectType	PKTM
*TmTransactionObjectType	PKTRANSACTION

The structures that the pointer types reference are opaque, and drivers cannot access the structure members. Because the structures are opaque, PEPROCESS is equivalent to PKPROCESS, and PETHREAD is equivalent to PKTHREAD.

[out, optional] HandleInformation

Drivers set this to NULL.

Return value

ObReferenceObjectByHandle returns STATUS_SUCCESS if the call is successful. Possible return values include the following error codes:

Return code	Description
STATUS_OBJECT_TYPE_MISMATCH	The ObjectType parameter specifies the wrong object type for the object that is identified by the Handle parameter.
STATUS_ACCESS_DENIED	The caller cannot be granted the requested access rights to the object.
STATUS_INVALID_HANDLE	The Handle parameter is not a valid object handle.

Remarks

A pointer to the object body is retrieved from the object table entry and returned to the caller by means of the Object parameter.

If AccessMode is UserMode, the requested access is compared to the granted access for the object. If AccessMode is KernelMode, the handle should originate in the kernel address space.

Starting with Windows 7, if AccessMode is KernelMode and handle is received from user address space, Driver Verifier issues bugcheck C4, subcode F6.

If the call succeeds, a pointer to the object body is returned to the caller and the pointer reference count is incremented. Incrementing this count prevents the object from being deleted while the pointer is being referenced. The caller must decrement the reference count with ObDereferenceObject as soon as it is done with the object.

Requirements

Requirement	Value
Minimum supported client	Available starting with Windows 2000.
Target Platform	Universal
Header	wdm.h (include Wdm.h, Ntddk.h, Ntifs.h)
Library	NtosKrnl.lib
DLL	NtosKrnl.exe
IRQL	PASSIVE_LEVEL
DDI compliance rules	HwStorPortProhibitedDDIs(storport), IrqlObPassive(wdm), TargetRelationNeedsRef(wdm)