Novell is now a part of Micro Focus

Security update for Linux Kernel (k_timer)


(Last modified: 11DEC2002)

solutions Security update for Linux Kernel (k_timer) SuSE Linux Maintenance Web (bcb8d250bb36400497e08ad87ed84d2e)

Applies to

Product(s): SuSE Linux Enterprise Server 7 for IBM zSeries

Package: k_timer
Release: 20021211
Obsoletes: none


Everyone should install this updated kernel.


Installation requires re-IPL of the Linux system.


This kernel contains fixes for the following problems:
Security-related fixes
  • Fix a problem in the tcp connection tracking code that could allow an attacker to make a machine unaccessible via the network for long time.
  • Fix security issues in 3270 fullscreen driver and other drivers
  • Fix problem with reparenting in thread group exit
  • Fix the extension header parsing bugs in the IPv6 netfilter code
  • Fix security hole in get_vm_area()
  • Discard SYN packets with the RST or FIN bit set; Linux would previously accept SYN packets with a RST or FIN bit set. This could be used to circumvent some packet filters who assume that these packets cannot open a new connection. This patch discards bogus SYN packets.
General fixes
  • Fix a theoretical race in the memory management (between free_pte() and truncate()) - adds additional checks to be safe against it
  • Fix race with LRU cache handling (also memory management)
  • Fix swapoff bug because of unsafe dirty check
  • Fix unsafe assert when freeing swap pages(could panic)
  • Fix memory leak with swapon/swapoff
  • Fix an O_DIRECT read cornercase problem
  • Fix possibly incorrect TLB flushing under extreme load and memory pressure
  • Fix SMP race in msgrcv (can be triggered only by extensive IPC usage)
Filesystem fixes
  • Fix rare ext3 data journaling race with truncate transactions
  • Fix ext3 data journaling race where files could show foreign data
  • Fix ext3 panic triggered when reading the partition while mounted
  • Fix potential ext3 recovery problem: old data could be in the log
S/390 and zSeries specific fixes
  • Fixes for S/390 IO Layer problems:
    • Fix hangs after a device is gone
    • Fix hangs after a tape attach or attached tape is not recognized
    • Fix fails to detect devices after 'not operational' messages
  • Fix 32-bit Emulation of recvmsg() system call timestamp conversion for input and out parameters
  • Fix CTC not restarting after I/O errors
  • Fix initialisation problems in the dasd discipline drivers
  • Fix initialisation problems when setting up IUCV connections
  • Fix the get block device size function of the xpram driver to i support XPRAM devices larger than 2GB
Configuration changes
To decrease the load on z/VM this kernel uses an on-demand timer tick. Unfortunately, it seems to interact poorly with the QDIO module in LPAR installations and adds some latency to the system performance. For a fixed 100 Hz timer tick and if you observe problems with the QDIO driver (the internal kernel process ksoftirqd_CPU# uses almost 100% CPU time in its slot) please install package k_deflt as described in article "Security update for Linux Kernel (k_deflt)" ( instead.
This Kernel includes OCO Modules from IBM which are updated to the 2002-08-16/Aug16 2002 drop.

Installation notes

Please note that the updated OCO modules require some APARs/PTFs installed for using OSA Express cards or Hipersockets:
Microcode levels for OSA-Express QDIO cards
zSeries 900 GA3:
Driver 3G, OSA microcode level 3.0A,
MCLs: J11204.007 and J11204.008 (available May 03, 2002)
zSeries 900 GA2:
Driver 3C, OSA microcode level: 2.26,
MCLs: J10630.013 and J10630.014 (available May 20, 2002)
zSeries 800 GA1:
Driver 3G, OSA microcode level 3.0A,
MCLs: J11204.007 and J11204.008 (available May 03, 2002)
S/390 Parallel Enterprise Servers G5 and G6:
Driver 26, OSA microcode level: 4.25,
MCLs: F99904.032 and F99904.033 (available May 16, 2002)
z/VM 4.3:
All enhancements included.
z/VM 4.2:
APAR: VM62938, PTF: UM30225
APAR: VM63034, PTF: UM30290
z/VM 4.1:
APAR: VM63034, PTF: UM30289
APAR: VM63036, PTF: UM30293
z/VM 3.1:
APAR: VM63034, PTF: UM30288
APAR: VM63036, PTF: UM30292
VM/ESA 2.4:
APAR: VM63034, PTF: UM30287
APAR: VM63036, PTF: UM30291
Kernel installation
This update is provided as an RPM package that can be manually installed on a running by using these command:
rpm -Uvh k_timer.rpm zipl
Please do not forget to run "zipl", otherwise your system will not IPL. Now IPL the new kernel with
shutdown -r now
To give local shell users time to gracefully log out, exchange "now" with the appropriate amount of time, for example "+5" for five minutes.

links to download packages

Download Source Packages

Download the source code of the patches for maintained products.


The Origin of this information may be internal or external to Novell. Novell makes all reasonable efforts to verify this information. However, the information provided in this document is for your information only. Novell makes no explicit or implied claims to the validity of this information.

Any trademarks referenced in this document are the property of their respective owners. Consult your product manuals for complete trademark information.

© Copyright Micro Focus or one of its affiliates