Article ID: 195998
Article Last Modified on 7/13/2004
APPLIES TO
- Microsoft SNA Server 3.0 Service Pack 4
- Microsoft SNA Server 4.0
- Microsoft SNA Server 3.0 Service Pack 2
- Microsoft SNA Server 3.0 Service Pack 3
- Microsoft SNA Server 4.0
- Microsoft SNA Server 4.0 Service Pack 1
This article was previously published under Q195998
SYMPTOMS
The SNA Server service may fail with an access violation after receiving a
badly formatted message from the SNA client APPC DLL (Wappc32.dll). This
may occur if the client application issues both [MC_]ALLOCATE and
RECEIVE_ALLOCATE from the same process.
If Drwtsn32.exe is configured as the default debugger on the SNA Server
system, the Drwtsn32.log file may contain an entry similar to the following
when this access violation occurs:
Application exception occurred:
App: <path>snaservr.exe (pid=<process ID #>)
When: <date> @ <time>
Exception number: c0000005 (access violation)
[...]
State Dump for Thread Id 0xd3
eax=012d007e ebx=012d036e ecx=012d5405 edx=017d88b8 esi=017d1451
edi=017d89bd
eip=003edcf6 esp=0118ff3c ebp=00000000 iopl=0
nv up ei pl nz na po cy
cs=001b ss=0023 ds=0023 es=0023 fs=0038 gs=0000 efl=00000207
function: s1pxsnd
003edcd9 b101 mov cl,0x1
003edcdb 8b5004 mov edx,[eax+0x4]
003edcde 668b5a06 mov bx,[edx+0x6]
003edce2 8bea mov ebp,edx
003edce4 662b5d04 sub bx,[ebp+0x4]
003edce8 6643 inc bx
003edcea 663b5c2412 cmp bx,[esp+0x12]
003edcef 7d19 jge s1pxsnd+0xa8a
003edcf1 8b6d00 mov ebp,[ebp]
003edcf4 fec1 inc cl
FAULT ->003edcf6 668b4506 mov ax,[ebp+0x6]
003edcfa 662b4504 sub ax,[ebp+0x4]
*----> Stack Back Trace <----*
FramePtr ReturnAd Param#1 Param#2 Param#3 Param#4 Function Name
00000000 00000000 00000000 00000000 00000000 00000000 snaservr!s1pxsnd
In addition, the Windows NT Application Event Log may contain the following
event which coincides with the same failure time as indicated in the
drwtsn32.log entry.
Event ID: 624
Source: SNA Server
Description: Creating dump file <snaroot>\snadump.log for Snaservr.exe
CAUSE
In a rare condition, the SNA Windows NT or Windows 95/98 client APPC DLL
(Wappc32.dll) may send a badly formatted message to the SNA Server if the
client application issues both [MC_]ALLOCATE and RECEIVE_ALLOCATE from the
same process. The SNA Server fails with an access violation when receiving
this badly formatted message.
RESOLUTION
SNA Server 3.0
A supported fix that corrects this problem is now available from Microsoft,
but has not been fully regression-tested and should be applied only to
systems experiencing this specific problem. If you are not severely
affected by this specific problem, Microsoft recommends that you wait for
the next Microsoft SNA Server version 3.0 service pack that contains this
fix.
To resolve this problem immediately, contact Microsoft Product Support
Services to obtain the fix. The updated Wappc32.dll must be applied to all
SNA Server client computers that access the SNA Server.
For a complete list of Microsoft Product Support Services phone numbers and
information on support costs, please go to the following address on the
World Wide Web:
The English version of this fix should have the following file attributes
or later:
File Name Date Time
----------------------------------
Wappc32.dll
NOTE: The Date and Time information for the above file will be provided in
this article as soon as it becomes available.
NOTE: Due to file dependencies, the most recent fix that contains the above
files may also contain additional files.
SNA Server 4.0
This problem was corrected in the latest SNA Server version 4.0 U.S.
Service Pack. For information on obtaining this Service Pack, query on
the following word in the Microsoft Knowledge Base (without the spaces):
STATUS
Microsoft has confirmed this to be a problem in SNA Server versions 3.0,
3.0 Service Pack 1, 3.0 Service Pack 2, 3.0 Service Pack 3, 4.0, and 4.0
Service Pack 1.
Keywords: kbbug kbfix KB195998