reactos/sdk/lib/cmlib/cminit.c
maharmstone e6a9aafe58 [CMLIB] Clean volatile registry entries in the same manner as Windows (#1883)
This fixes the crashes in HvpGetCellMapped on Windows Server 2003 when booting from Freeloader, as mentioned in maharmstone/btrfs#16.

When the bootloader loads the system hive, it cleans the data pertaining to any volatile keys. The Windows bootloader does this by setting SubKeyCounts[Volatile] to 0. After boot, the kernel marks any cell where this is 0 but SubKeyLists[Volatile] isn't HCELL_NIL as dirty, meaning that the sanitized version will then get flushed to the disk.

Because Freeloader sets SubKeyLists[Volatile] to HCELL_NIL straightaway, Windows thinks the cell is clean, and can unload it without flushing. If it then reads it from the disk, it will crash in HvpGetCellMapped due to the stale volatile pointers.

If you break on nt!CmpInitializeSystemHive on Windows and "gu" to the let the function run, you'll see that DirtyVector of the HHIVE has only the first 8 bits set. If you run it using the official bootloader, it'll have a lot more than that.
2019-08-27 02:39:27 +02:00

143 lines
4.1 KiB
C

/*
* PROJECT: Registry manipulation library
* LICENSE: GPL - See COPYING in the top level directory
* COPYRIGHT: Copyright 2005 Filip Navara <navaraf@reactos.org>
* Copyright 2001 - 2005 Eric Kohl
*/
#include "cmlib.h"
#define NDEBUG
#include <debug.h>
ULONG CmlibTraceLevel = 0;
// FIXME: This function must be replaced by CmpCreateRootNode from ntoskrnl/config/cmsysini.c
// (and CmpCreateRootNode be moved there).
BOOLEAN CMAPI
CmCreateRootNode(
PHHIVE Hive,
PCWSTR Name)
{
UNICODE_STRING KeyName;
PCM_KEY_NODE KeyCell;
HCELL_INDEX RootCellIndex;
/* Initialize the node name and allocate it */
RtlInitUnicodeString(&KeyName, Name);
RootCellIndex = HvAllocateCell(Hive,
FIELD_OFFSET(CM_KEY_NODE, Name) +
CmpNameSize(Hive, &KeyName),
Stable,
HCELL_NIL);
if (RootCellIndex == HCELL_NIL) return FALSE;
/* Seutp the base block */
Hive->BaseBlock->RootCell = RootCellIndex;
Hive->BaseBlock->CheckSum = HvpHiveHeaderChecksum(Hive->BaseBlock);
/* Get the key cell */
KeyCell = (PCM_KEY_NODE)HvGetCell(Hive, RootCellIndex);
if (!KeyCell)
{
HvFreeCell(Hive, RootCellIndex);
return FALSE;
}
/* Setup the cell */
KeyCell->Signature = CM_KEY_NODE_SIGNATURE;
KeyCell->Flags = KEY_HIVE_ENTRY | KEY_NO_DELETE;
// KeQuerySystemTime(&KeyCell->LastWriteTime);
KeyCell->LastWriteTime.QuadPart = 0ULL;
KeyCell->Parent = HCELL_NIL;
KeyCell->SubKeyCounts[Stable] = 0;
KeyCell->SubKeyCounts[Volatile] = 0;
KeyCell->SubKeyLists[Stable] = HCELL_NIL;
KeyCell->SubKeyLists[Volatile] = HCELL_NIL;
KeyCell->ValueList.Count = 0;
KeyCell->ValueList.List = HCELL_NIL;
KeyCell->Security = HCELL_NIL;
KeyCell->Class = HCELL_NIL;
KeyCell->ClassLength = 0;
KeyCell->MaxNameLen = 0;
KeyCell->MaxClassLen = 0;
KeyCell->MaxValueNameLen = 0;
KeyCell->MaxValueDataLen = 0;
KeyCell->NameLength = CmpCopyName(Hive, KeyCell->Name, &KeyName);
if (KeyCell->NameLength < KeyName.Length) KeyCell->Flags |= KEY_COMP_NAME;
/* Return success */
HvReleaseCell(Hive, RootCellIndex);
return TRUE;
}
static VOID CMAPI
CmpPrepareKey(
PHHIVE RegistryHive,
PCM_KEY_NODE KeyCell);
static VOID CMAPI
CmpPrepareIndexOfKeys(
PHHIVE RegistryHive,
PCM_KEY_INDEX IndexCell)
{
ULONG i;
if (IndexCell->Signature == CM_KEY_INDEX_ROOT ||
IndexCell->Signature == CM_KEY_INDEX_LEAF)
{
for (i = 0; i < IndexCell->Count; i++)
{
PCM_KEY_INDEX SubIndexCell = HvGetCell(RegistryHive, IndexCell->List[i]);
if (SubIndexCell->Signature == CM_KEY_NODE_SIGNATURE)
CmpPrepareKey(RegistryHive, (PCM_KEY_NODE)SubIndexCell);
else
CmpPrepareIndexOfKeys(RegistryHive, SubIndexCell);
}
}
else if (IndexCell->Signature == CM_KEY_FAST_LEAF ||
IndexCell->Signature == CM_KEY_HASH_LEAF)
{
PCM_KEY_FAST_INDEX HashCell = (PCM_KEY_FAST_INDEX)IndexCell;
for (i = 0; i < HashCell->Count; i++)
{
PCM_KEY_NODE SubKeyCell = HvGetCell(RegistryHive, HashCell->List[i].Cell);
CmpPrepareKey(RegistryHive, SubKeyCell);
}
}
else
{
DPRINT1("IndexCell->Signature %x\n", IndexCell->Signature);
ASSERT(FALSE);
}
}
static VOID CMAPI
CmpPrepareKey(
PHHIVE RegistryHive,
PCM_KEY_NODE KeyCell)
{
PCM_KEY_INDEX IndexCell;
ASSERT(KeyCell->Signature == CM_KEY_NODE_SIGNATURE);
KeyCell->SubKeyCounts[Volatile] = 0;
// KeyCell->SubKeyLists[Volatile] = HCELL_NIL; // FIXME! Done only on Windows < XP.
/* Enumerate and add subkeys */
if (KeyCell->SubKeyCounts[Stable] > 0)
{
IndexCell = HvGetCell(RegistryHive, KeyCell->SubKeyLists[Stable]);
CmpPrepareIndexOfKeys(RegistryHive, IndexCell);
}
}
VOID CMAPI
CmPrepareHive(
PHHIVE RegistryHive)
{
PCM_KEY_NODE RootCell;
RootCell = HvGetCell(RegistryHive, RegistryHive->BaseBlock->RootCell);
CmpPrepareKey(RegistryHive, RootCell);
}