USN-661-1: Linux kernel regression

30 October 2008

linux regression

A security issue affects these releases of Ubuntu and its derivatives:

  • Ubuntu 8.10

Software Description

  • linux
  • procps


Version 2.6.27 of the Linux kernel changed the order of options in TCP headers. While this change was RFC-compliant, it was found that some old routers and consumer DSL modems would not route traffic for these systems when TCP timestamps were enabled. As a workaround, TCP timestamps were disabled via sysctl.

This update restores the previous ordering of TCP options, and reenables TCP timestamps. We apologize for the inconvenience.

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 8.10
linux-image-2.6.27-7-generic - 2.6.27-7.15
linux-image-2.6.27-7-server - 2.6.27-7.15
linux-image-2.6.27-7-virtual - 2.6.27-7.15
procps - 1:3.2.7-9ubuntu2.1

To update your system, please follow these instructions:

After a standard system upgrade you need to reboot your computer to effect the necessary changes.