SNA Server Fails Unexpectedly With Access Violation in S1PUC62 (312819)



The information in this article applies to:

  • Microsoft SNA Server 4.0

This article was previously published under Q312819

SYMPTOMS

The SNA Server service (Anaservr.exe) may fail unexpectedly with an access violation, causing all users to lose their SNA sessions. SNA Servers configured to support LU 6.2 sessions to a host system may experience this problem.

If Drwtsn32.exe is configured as the system's default debugger, the Drwtsn32.log file will indicate an access violation fault in routine s1puc62(). The log entry will be similar to the following:
Application exception occurred:
        App: exe\snaservr.dbg (pid=198)
        When: 11/2/2001 @ 19:9:1.272
        Exception number: c0000005 (access violation)

[data omitted]

function: s1puc62
        0101625f 0fbf4610         movsx   eax,word ptr [esi+0x10]    ds:02345a67=????
        01016263 c644241301       mov     byte ptr [esp+0x13],0x1      ss:01bde913=??
        01016268 8b0c85e04a0f01                                  ds:00000000=????????
                                  mov     ecx,[s1scb+0x4e20 (010f4ae0)+eax*4]
        0101626f 885916           mov     [ecx+0x16],bl                ds:02345a08=??
        01016272 e9ab010000       jmp     s1puc62+0x3c2 (01016422)
        01016277 807e13ff         cmp     byte ptr [esi+0x13],0xff     ds:02345a66=??
        0101627b 0f85e7000000     jne     s1puc62+0x308 (01016368)
        01016281 668b6f0a         mov     bp,[edi+0xa]               ds:021b60ff=????
        01016285 0fbfd5           movsx   edx,bp
        01016288 8b0495e04a0f01                                  ds:ffffb2c4=????????
                                  mov     eax,[s1scb+0x4e20 (010f4ae0)+edx*4]
FAULT ->0101628f 8a4815           mov     cl,[eax+0x15]                ds:0102ea06=00
        01016292 3acb             cmp     cl,bl
        01016294 0f84b5000000     je      s1puc62+0x2ef (0101634f)
        0101629a 668b500c         mov     dx,[eax+0xc]               ds:0102ea07=9090
        0101629e 663bd3           cmp     dx,bx
        010162a1 742d             jz      s1puc62+0x270 (010162d0)
        010162a3 0fbfd2           movsx   edx,dx
        010162a6 8b1495bcf40e01                                  ds:ffffb2c4=????????
                                  mov     edx,[s1rcb+0xe25c (010ef4bc)+edx*4]
        010162ad 0fbf5210         movsx   edx,word ptr [edx+0x10]    ds:01029ccb=8d55
        010162b1 8b1495dc520b01                                  ds:ffffb2c4=????????
                                  mov     edx,[G_comp_flat2+0x59fc (010b52dc)+edx*4]
        010162b8 385a08           cmp     [edx+0x8],bl                 ds:01029cca=53
        010162bb 7413             jz      s1puc62+0x270 (010162d0)

*----> Stack Back Trace <----*

FramePtr ReturnAd Param#1  Param#2  Param#3  Param#4  Function Name
0000b2c4 00000000 00000000 00000000 00000000 00000000 snaservr!s1puc62  (FPO: [EBP 0x00000000] [0,3,4])
0000b2cc 00000000 00000000 00000000 00000000 00000000 snaservr!<nosymbols> 

State Dump for Thread Id 0xcb

eax=000000ac ebx=00beff24 ecx=00000090 edx=00000000 esi=7ffdf000 edi=00000000
eip=77f682cb esp=00beff00 ebp=00beff54 iopl=0         nv up ei pl nz ac pe cy
cs=001b  ss=0023  ds=0023  es=0023  fs=0038  gs=0000             efl=00000213
				
In addition, an event similar to the following will be logged in the Windows NT or Windows 2000 Application Event Log:
Event ID: 624
Source: SNA Server
Description: Creating dump file C:\SNA\traces\snadump.log for SNASERVR.EXE

CAUSE

A message received by the SNA Server service contained an index to an invalid conversation control block. The access violation occurs when the SNA Server service attempts to access the invalid conversation control block.

RESOLUTION

A supported fix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Apply it only to computers that are experiencing this specific problem. This fix may receive additional testing. Therefore, if you are not severely affected by this problem, Microsoft recommends that you wait for the next Microsoft SNA Server version 4.0 service pack that contains this hotfix.

To resolve this problem immediately, contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information about support costs, visit the following Microsoft Web site:NOTE: In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The typical support costs will apply to additional support questions and issues that do not qualify for the specific update in question.

The English version of this fix should have the following file attributes or later:

File nameDateTime
Snaservr.exe11/08/20016:46

NOTE: Because of file dependencies, the most recent fix that contains the preceding files may also contain additional files.

STATUS

Microsoft has confirmed that this is a problem in Microsoft SNA Server version 4.0.

Modification Type:MinorLast Reviewed:10/6/2005
Keywords:kbbug kbfix kbQFE KB312819