Debian 514-1 Critical: Kernel 2.2.20 Local Root Access Exploit

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) these problems have been fixed in
version 9woody1 of Linux 2.2 kernel images for the sparc architecture
and in version 2.2.20-5woody3 of Linux 2.2.20 source.

For the unstable distribution (sid) these problems have been fixed in
version 9.1 of Linux 2.2 kernel images for the sparc architecture.

This...