linux-kernel-2.2.20-i386+m68k+powerpc - failing function and TLB flush

Paul Starzetz and Wojciech Purczynski of isec.pl discovered a critical
security vulnerability in the memory management code of Linux inside
the mremap(2) system call. Due to flushing the TLB (Translation
Lookaside Buffer, an address cache) too early it is possible for an
attacker to trigger a local root exploit.

The attack vectors for 2.4.x and 2.2.x kernels are exclusive for the
respective kernel series, though. We formerly believed that the
exploitable vulnerability in 2.4.x does not exist in 2.2.x which is
still true. However, it turned out that a second (sort of)
vulnerability is indeed exploitable in 2.2.x, but not in 2.4.x, with a
different exploit, of course.

For the stable distribution (woody) this problem has been fixed in
the following versions and architectures:

For the unstable distribution (sid) this problem will be fixed soon
for the architectures that still ship a 2.2.x kernel package.

We recommend that you upgrade your Linux kernel package.

Vulnerability matrix for CAN-2004-0077