Dear SCO Customer,

The enclosed Support Level Supplement, (SLS) OSS469A, the Networking and 
SMP Supplement, corrects problems in multi-processor systems and in 
networking.  See the list below for more details on specific problems
addressed by this SLS.

RELEASE INFORMATION

SLS OSS469A is intended for use on these products:

          SCO OpenServer System Release 5.0.4 (all configurations)

NOTE: To obtain the same set of corrections for SCO OpenServer Release
      5.0.0 and 5.0.2, and Internet FastStart 1.0.0 and 1.1.0, please
      see SLS OSS468A.

Prerequisites:

        On OpenServer 5.0.4, the following update MUST be installed
        prior to this patch:

           - SCO OpenServer Release Supplement 5.0.4c (rs504c)
             ftp://ftp.sco.com/Supplements/rs504c/

NOTE: OSS469A supersedes the SCO Security Patch SSE010, a patch for IP
      denial of service vulnerabilities. 

OSS469A corrects the following problems:

1. System "hang" (no keyboard response or other apparent system activity)
   under a network load which may be followed, after several minutes, by 
   a warning message similar to:

        WARNING: IP: spinning on pcb ... 

   This only occurs on multi-processor systems, and may be accompanied 
   by a depletion of streams buffers.

2. Lock timeout panic in "narrowcast" or "cpuintr"; this only occurs on
   multi-processor systems.

3. Unexpected Out of Band Data denial-of-service attack; an exploit has 
   been distributed under the name "winnuke".

4. Spoofed Self-connect Packets denial-of-service attack; exploits have 
   been distributed under the names "land" and "latierra".

NOTE: OpenServer systems are NOT vulnerable to IP denial-of-service
attacks based on fragmented packets with invalid sizes.  Exploits
have been distributed under the names "teardrop", "bonk", and "newtear".

5. Warning message "WARNING: NLM: request to server failed:", followed 
   by a panic in "printf" called from the NFS lock manager.

6. Incoming udp broadcasts can bring down a system by using up all its 
   streams buffers.  This may be caused because a program, such as 
   scologin, has stopped reading incoming packets, or by a flood of 
   incoming packets which are arriving too fast for a slow system.

7. AFPS performance problem. Setting the option TCP_NODELAY improves 
   performance of certain size transactions, which would otherwise show 
   large degradation in performance.
   
8. UNIX domain sockets performance problem. Performance of UNIX domain 
   sockets would degrade with multiple CPUs compared with a single CPU.


I. INSTALLING SLS OSS469A

  1. Prepare the media for installation.

     Download the OSS469A media image file (oss469a.Z file), place
     the file in the /tmp directory, uncompress and rename the file
     by typing the following commands:

                uncompress /tmp/oss469a.Z
                mv /tmp/oss469a /tmp/VOL.000.000

  2. Run the Software Manager with the command:

             # scoadmin software

     or double-click on the Software Manager icon in the desktop.

  3. Pull down the "Software" menu and select "Install New".

  4. When prompted for the host to install from, choose the local
     machine and then "Continue".

  5. When prompted to select the media device:

     If you are installing this SLS from diskette media, select the 
     appropriate floppy disk drive and then "Continue". Proceed to step 6.

     If you are installing this SLS from media images per step 1, select 
     "Media Images", then "Continue".  When prompted for the "Image 
     Directory", enter "/tmp" (or the directory where you placed the VOL 
     file in step 1) and then select "OK".

  6. When prompted to select software to install, ensure that the "OSS469A" 
     entry is highlighted. Choose "Install".

  7. You will be asked whether or not you want to relink the kernel.

     Enter "y" or "n" based on this message. Note that you will not be able 
     to make use of the patch until you relink the kernel. Therefore, it is 
     suggested that you answer "y" to this question.

  8. Once the installation finishes, quit the Software Manager.  Installation 
     of SLS OSS469A is now complete. The changes will take effect the next 
     time you reboot the system.

  9. Log in as root on tty01, and shut down the system:

              # shutdown -g0 -y

    After shutting down and rebooting the machine, application of the patch 
    is complete.


II. REMOVING SLS OSS469A

Note: Patches must be rolled back in the reverse order in which they
      were installed on a per-component basis.

  1. Log in as root.

  2. Execute the command:

             # scoadmin software

     or double-click on the Software Manager icon in the desktop.

  3. Highlight "OSS469A: The Networking and SMP Supplement."

  4. Pull down the "Software" menu and select "Remove Software".

  5. You will be asked whether or not you want to relink the kernel.

     Enter "y" or "n" based on this message. Note that package removal
     will not take effect until you relink the kernel.  Therefore, it 
     is suggested that you answer "y" to this question.

  6. Once the removal finishes, quit the Software Manager.

  7. As root on tty01, shut down the system:

              # shutdown -g0 -y

    After shutting down and rebooting the machine, application of the patch 
    is complete.


If you have questions regarding this SLS, or the product on which it is 
installed, please contact your software supplier.

We appreciate your business.

SCO Support Services