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[NTVDM]

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Avoid array indexing with invalid indexes, always.


svn path=/trunk/; revision=67347
This commit is contained in:
Aleksandar Andrejevic 2015-04-22 12:13:14 +00:00
parent f1c1d10824
commit ffb82658c9
2 changed files with 19 additions and 9 deletions
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25
reactos/subsystems/mvdm/ntvdm/dos/dos32krnl/emsdrv.c
View file

@ -35,12 +35,18 @@ static PVOID EmsMemory = NULL;
/* PRIVATE FUNCTIONS **********************************************************/ /* PRIVATE FUNCTIONS **********************************************************/
static PEMS_HANDLE GetHandleRecord(USHORT Handle)
{
if (Handle >= EMS_MAX_HANDLES) return NULL;
return &HandleTable[Handle];
}
static USHORT EmsFree(USHORT Handle) static USHORT EmsFree(USHORT Handle)
{ {
PLIST_ENTRY Entry; PLIST_ENTRY Entry;
PEMS_HANDLE HandleEntry = &HandleTable[Handle]; PEMS_HANDLE HandleEntry = GetHandleRecord(Handle);
if (Handle >= EMS_MAX_HANDLES || !HandleEntry->Allocated) if (HandleEntry == NULL || !HandleEntry->Allocated)
{ {
return EMS_STATUS_INVALID_HANDLE; return EMS_STATUS_INVALID_HANDLE;
} }
@ -131,7 +137,7 @@ static PEMS_PAGE GetLogicalPage(PEMS_HANDLE Handle, USHORT LogicalPage)
static USHORT EmsMap(USHORT Handle, UCHAR PhysicalPage, USHORT LogicalPage) static USHORT EmsMap(USHORT Handle, UCHAR PhysicalPage, USHORT LogicalPage)
{ {
PEMS_PAGE PageEntry; PEMS_PAGE PageEntry;
PEMS_HANDLE HandleEntry = &HandleTable[Handle]; PEMS_HANDLE HandleEntry = GetHandleRecord(Handle);
if (PhysicalPage >= EMS_PHYSICAL_PAGES) return EMS_STATUS_INV_PHYSICAL_PAGE; if (PhysicalPage >= EMS_PHYSICAL_PAGES) return EMS_STATUS_INV_PHYSICAL_PAGE;
if (LogicalPage == 0xFFFF) if (LogicalPage == 0xFFFF)
@ -141,7 +147,10 @@ static USHORT EmsMap(USHORT Handle, UCHAR PhysicalPage, USHORT LogicalPage)
return EMS_STATUS_OK; return EMS_STATUS_OK;
} }
if (Handle >= EMS_MAX_HANDLES || !HandleEntry->Allocated) return EMS_STATUS_INVALID_HANDLE; if (HandleEntry == NULL || !HandleEntry->Allocated)
{
return EMS_STATUS_INVALID_HANDLE;
}
PageEntry = GetLogicalPage(HandleEntry, LogicalPage); PageEntry = GetLogicalPage(HandleEntry, LogicalPage);
if (!PageEntry) return EMS_STATUS_INV_LOGICAL_PAGE; if (!PageEntry) return EMS_STATUS_INV_LOGICAL_PAGE;
@ -224,9 +233,9 @@ static VOID WINAPI EmsIntHandler(LPWORD Stack)
if (Data->SourceType) if (Data->SourceType)
{ {
/* Expanded memory */ /* Expanded memory */
HandleEntry = &HandleTable[Data->SourceHandle]; HandleEntry = GetHandleRecord(Data->SourceHandle);
if (Data->SourceHandle >= EMS_MAX_HANDLES || !HandleEntry->Allocated) if (HandleEntry == NULL || !HandleEntry->Allocated)
{ {
setAL(EMS_STATUS_INVALID_HANDLE); setAL(EMS_STATUS_INVALID_HANDLE);
break; break;
@ -253,9 +262,9 @@ static VOID WINAPI EmsIntHandler(LPWORD Stack)
if (Data->DestType) if (Data->DestType)
{ {
/* Expanded memory */ /* Expanded memory */
HandleEntry = &HandleTable[Data->DestHandle]; HandleEntry = GetHandleRecord(Data->DestHandle);
if (Data->SourceHandle >= EMS_MAX_HANDLES || !HandleEntry->Allocated) if (HandleEntry == NULL || !HandleEntry->Allocated)
{ {
setAL(EMS_STATUS_INVALID_HANDLE); setAL(EMS_STATUS_INVALID_HANDLE);
break; break;

3
reactos/subsystems/mvdm/ntvdm/dos/dos32krnl/himem.c
View file

@ -46,9 +46,10 @@ static ULONG BitmapBuffer[(XMS_BLOCKS + 31) / 32];
static inline PXMS_HANDLE GetHandleRecord(WORD Handle) static inline PXMS_HANDLE GetHandleRecord(WORD Handle)
{ {
PXMS_HANDLE Entry = &HandleTable[Handle - 1]; PXMS_HANDLE Entry;
if (Handle == 0 || Handle >= XMS_MAX_HANDLES) return NULL; if (Handle == 0 || Handle >= XMS_MAX_HANDLES) return NULL;
Entry = &HandleTable[Handle - 1];
return Entry->Size ? Entry : NULL; return Entry->Size ? Entry : NULL;
} }