Virtual channel access violation in mstscax.dll with Vista SP1

[Guest Preference]

Hello,

 

I have a dll registered to use virtual channel in mstsc

(HKEY_CURRENT_USER\Software\Microsoft\Terminal Server Client\Default\Addins),

before mstsc released with vista sp1 all works fine, but with the latest

whenever I click on connect in mstsc I will get an access violation.

 

First-chance exception at 0x6beab2f5 in mstsc.exe: 0xC0000005: Access

violation reading location 0x00000000

 

Tried to recompile my dll, doing nothing, just returning, and the crash

append too.

If I unregister the dll all works.

Has something related to virtual channel implementation changed? I checked

in many places but I have found nothing.

 

In the debug session I see following:

 

1. The sentence:

 

uRet = gpEntryPoints->pVirtualChannelInit( (LPVOID *)&gphChannel,

(PCHANNEL_DEF)&cd,

1,VIRTUAL_CHANNEL_VERSION_WIN2000,(PCHANNEL_INIT_EVENT_FN)VirtualChannelInitEventProc );

 

RETURNS uRet == 0 OK

 

2. Next inside the VirtualChannelInitEventProc, the sentence:

 

case CHANNEL_EVENT_CONNECTED:

{

if ( OUTPUT_DEBUG_INFO == 1 )

{

OutputDebugString( _T("CHANNEL_EVENT_CONNECTED\n") );

}

// open channel

ui = gpEntryPoints->pVirtualChannelOpen( gphChannel,

&gdwOpenChannel, CHANNELNAME,

(PCHANNEL_OPEN_EVENT_FN)VirtualChannelOpenEvent );

if ( ui == CHANNEL_RC_OK )

{

 

}

 

Returns ui == 0 OK, but the call-back function VirtualChannelOpenEvent never

is called and when exit from VirtualChannelInitEventProc, then following

exception is thrown:

First-chance exception at 0x6beab2f5 in mstsc.exe: 0xC0000005: Access

violation reading location 0x00000000.

 

The error in Event Viewer is following:

 

Nombre de registro:Application

Origen: Application Error

Fecha: 07/04/2008 16:33:04

Id. del evento:1000

Categoría de la tarea:(100)

Nivel: Error

Palabras clave:Clásico

Usuario: No disponible

Equipo: MyComputer

Descripción:

Aplicación con errores mstsc.exe, versión 6.0.6001.18000, marca de hora

0x47919247, módulo con errores mstscax.dll, versión 6.0.6001.18000, marca de

tiempo 0x4791a718, código de excepción 0xc0000005, desplazamiento con errores

0x0015b2f5, Id. de proceso 0xd74, hora de inicio de la aplicación

0x01c898bc48a32825.

XML de evento:

<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">

<System>

<Provider Name="Application Error" />

<EventID Qualifiers="0">1000</EventID>

<Level>2</Level>

<Task>100</Task>

<Keywords>0x80000000000000</Keywords>

<TimeCreated SystemTime="2008-04-07T14:33:04.000Z" />

<EventRecordID>9553</EventRecordID>

<Channel>Application</Channel>

<Computer>MyComputer</Computer>

<Security />

</System>

<EventData>

<Data>mstsc.exe</Data>

<Data>6.0.6001.18000</Data>

<Data>47919247</Data>

<Data>mstscax.dll</Data>

<Data>6.0.6001.18000</Data>

<Data>4791a718</Data>

<Data>c0000005</Data>

<Data>0015b2f5</Data>

<Data>d74</Data>

<Data>01c898bc48a32825</Data>

</EventData>

</Event>

 

Someone has any idea?

Thanks

[Guest Ratnesh Yadav [MSFT]]

Re: Virtual channel access violation in mstscax.dll with Vista SP1

 

Answered in following post,

http://www.microsoft.com/communities/newsgroups/en-us/default.aspx?dg=microsoft.public.win32.programmer.networks&tid=8d87dbcc-bc1d-4b23-860b-b716c5ed9e75&cat=&lang=en&cr=US&sloc=&p=1

 

Ratnesh

 

"Preference" <preference@newsgroup.nospam> wrote in message

news:7872704E-857E-474A-B5D4-FB02EAD58C93@microsoft.com...

> Hello,

>

> I have a dll registered to use virtual channel in mstsc

> (HKEY_CURRENT_USER\Software\Microsoft\Terminal Server

> Client\Default\Addins),

> before mstsc released with vista sp1 all works fine, but with the latest

> whenever I click on connect in mstsc I will get an access violation.

>

> First-chance exception at 0x6beab2f5 in mstsc.exe: 0xC0000005: Access

> violation reading location 0x00000000

>

> Tried to recompile my dll, doing nothing, just returning, and the crash

> append too.

> If I unregister the dll all works.

> Has something related to virtual channel implementation changed? I checked

> in many places but I have found nothing.

>

> In the debug session I see following:

>

> 1. The sentence:

>

> uRet = gpEntryPoints->pVirtualChannelInit( (LPVOID *)&gphChannel,

> (PCHANNEL_DEF)&cd,

> 1,VIRTUAL_CHANNEL_VERSION_WIN2000,(PCHANNEL_INIT_EVENT_FN)VirtualChannelInitEventProc

> );

>

> RETURNS uRet == 0 OK

>

> 2. Next inside the VirtualChannelInitEventProc, the sentence:

>

> case CHANNEL_EVENT_CONNECTED:

> {

> if ( OUTPUT_DEBUG_INFO == 1 )

> {

> OutputDebugString( _T("CHANNEL_EVENT_CONNECTED\n") );

> }

> // open channel

> ui = gpEntryPoints->pVirtualChannelOpen( gphChannel,

> &gdwOpenChannel, CHANNELNAME,

> (PCHANNEL_OPEN_EVENT_FN)VirtualChannelOpenEvent );

> if ( ui == CHANNEL_RC_OK )

> {

>

> }

>

> Returns ui == 0 OK, but the call-back function VirtualChannelOpenEvent

> never

> is called and when exit from VirtualChannelInitEventProc, then following

> exception is thrown:

> First-chance exception at 0x6beab2f5 in mstsc.exe: 0xC0000005: Access

> violation reading location 0x00000000.

>

> The error in Event Viewer is following:

>

> Nombre de registro:Application

> Origen: Application Error

> Fecha: 07/04/2008 16:33:04

> Id. del evento:1000

> Categoría de la tarea:(100)

> Nivel: Error

> Palabras clave:Clásico

> Usuario: No disponible

> Equipo: MyComputer

> Descripción:

> Aplicación con errores mstsc.exe, versión 6.0.6001.18000, marca de hora

> 0x47919247, módulo con errores mstscax.dll, versión 6.0.6001.18000, marca

> de

> tiempo 0x4791a718, código de excepción 0xc0000005, desplazamiento con

> errores

> 0x0015b2f5, Id. de proceso 0xd74, hora de inicio de la aplicación

> 0x01c898bc48a32825.

> XML de evento:

> <Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">

> <System>

> <Provider Name="Application Error" />

> <EventID Qualifiers="0">1000</EventID>

> <Level>2</Level>

> <Task>100</Task>

> <Keywords>0x80000000000000</Keywords>

> <TimeCreated SystemTime="2008-04-07T14:33:04.000Z" />

> <EventRecordID>9553</EventRecordID>

> <Channel>Application</Channel>

> <Computer>MyComputer</Computer>

> <Security />

> </System>

> <EventData>

> <Data>mstsc.exe</Data>

> <Data>6.0.6001.18000</Data>

> <Data>47919247</Data>

> <Data>mstscax.dll</Data>

> <Data>6.0.6001.18000</Data>

> <Data>4791a718</Data>

> <Data>c0000005</Data>

> <Data>0015b2f5</Data>

> <Data>d74</Data>

> <Data>01c898bc48a32825</Data>

> </EventData>

> </Event>

>

> Someone has any idea?

> Thanks

>