It was not even a week ago that the
Linux 2.6.21 kernel was released, but now the 2.6.21.1 kernel has entered the world. The first minor revision in the Linux 2.6.21 branch fixes an RT0 header IPv6 change and a fix for the netlink fib. The 2.6.21.1 change-log is available
here and the source is available from
Kernel.org.