VOID
NTAPI
ExpFreeHandleTableEntry(IN PHANDLE_TABLE HandleTable,
IN EXHANDLE Handle,
IN PHANDLE_TABLE_ENTRY HandleTableEntry)
{
ULONG OldValue, NewValue, *Free;
ULONG i;
PAGED_CODE();
/* Sanity checks */
ASSERT(HandleTableEntry->Object == NULL);
ASSERT(HandleTableEntry == ExpLookupHandleTableEntry(HandleTable, Handle));
/* Decrement the handle count */
InterlockedDecrement(&HandleTable->HandleCount);
/* Mark the handle as free */
NewValue = (ULONG)Handle.Value & ~(SizeOfHandle(1) - 1);
/* Check if we're FIFO */
if (!HandleTable->StrictFIFO)
{
/* Select a lock index */
i = (NewValue >> 2) % 4;
/* Select which entry to use */
Free = (HandleTable->HandleTableLock[i].Locked) ?
&HandleTable->FirstFree : &HandleTable->LastFree;
}
/// <summary>
/// Change handle granted access
/// </summary>
/// <param name="pAccess">Request params</param>
/// <returns>Status code</returns>
NTSTATUS BBGrantAccess( IN PHANDLE_GRANT_ACCESS pAccess )
{
NTSTATUS status = STATUS_SUCCESS;
PEPROCESS pProcess = NULL;
PHANDLE_TABLE pTable = NULL;
PHANDLE_TABLE_ENTRY pHandleEntry = NULL;
EXHANDLE exHandle;
// Validate dynamic offset
if (dynData.ObjTable == 0)
{
DPRINT( "BlackBone: %s: Invalid ObjTable address\n", __FUNCTION__ );
return STATUS_INVALID_ADDRESS;
}
status = PsLookupProcessByProcessId( (HANDLE)pAccess->pid, &pProcess );
if (NT_SUCCESS( status ))
{
pTable = *(PHANDLE_TABLE*)((PUCHAR)pProcess + dynData.ObjTable);
exHandle.Value = (ULONG_PTR)pAccess->handle;
if (pTable)
pHandleEntry = ExpLookupHandleTableEntry( pTable, exHandle );
if (ExpIsValidObjectEntry( pHandleEntry ))
{
pHandleEntry->GrantedAccessBits = pAccess->access;
}
else
{
DPRINT( "BlackBone: %s: 0x%X:0x%X handle is invalid. HandleEntry = 0x%p\n",
__FUNCTION__, pAccess->pid, pAccess->handle, pHandleEntry );
status = STATUS_UNSUCCESSFUL;
}
}
else
DPRINT( "BlackBone: %s: PsLookupProcessByProcessId failed with status 0x%X\n", __FUNCTION__, status );
if (pProcess)
ObDereferenceObject( pProcess );
return status;
}