Snalink.exe (SNADLC/802.2) Access Violation in Sbpa4snd() (161774)


The information in this article applies to:

  • Microsoft SNA Server 2.0
  • Microsoft SNA Server 2.1
  • Microsoft SNA Server 2.11
This article was previously published under Q161774

SYMPTOMS

In very rare conditions, the SNA Server 802.2 link service (supporting an SNA connection over Token Ring, Ethernet, or FDDI) may encounter an access violation (AV) leading to the following errors:
  • Users lose their sessions over any SNA Server connection using this link service.
  • The following Windows NT application event log error occurs:
    Event ID: 624
    Source: SNADLC1
    Creating dump file C:\SNA\traces\snadump.log for SNALINK.EXE
  • A Drwtsn32.log entry is created that indicates an application exception error occurred in Snalink.dbg: 
          Application exception occurred:
            App: snalink.DBG (pid=<process id>)
            Exception number: c0000005 (access violation)

      State Dump for Thread Id <thread>

      eax=0019000a ebx=00620c00 ecx=00000381 edx=00000103 esi=00620d6a
      edi=012202b5
      eip=003d96c7 esp=003cfeac ebp=01025f28 iopl=0         nv up ei pl nz
      na po nc
      cs=001b  ss=0023  ds=0023  es=0023  fs=0038  gs=0000
      efl=00000206

      function: sbpa4snd
      [...]

          003d96c4 8b6d00       mov   ebp,[ebp]
ss:0170484a=????????
      FAULT ->003d96c7 66894504     mov   [ebp+0x4],ax
ss:0170484b=????

CAUSE

An access violation may occur if the Snadlc.dll link service formats data to pass to the SNA Server service while Dlc.sys passes up empty buffers with the total data length of a certain size. This is a rare condition that has only been observed at one customer site.

RESOLUTION

A fix is available to correct this problem.

STATUS

Microsoft has confirmed this to be a problem in SNA Server versions 2.0, 2.1, and 2.11. A supported fix is now available, but has not been fully regression-tested and should be applied only to systems experiencing this specific problem. Unless you are severely impacted by this specific problem, Microsoft recommends that you wait for the next Service Pack that contains this fix. Contact Microsoft Technical Support for more information.
Modification Type:MajorLast Reviewed:10/23/2003
Keywords:kbbug kbfix KB161774
©2003 Microsoft Corporation. All rights reserved.