DSA 466-1: New Linux 2.2.10 packages fix local root exploit (powerpc)

New Kernel 2.2.10 PowerPC packages has been released for Debian GNU/Linux

--------------------------------------------------------------------------
Debian Security Advisory DSA 466-1 security@debian.org
http://www.debian.org/security/ Martin Schulze
March 18th, 2004 http://www.debian.org/security/faq
---------------------------------------------------------------------------

Package : kernel-source-2.2.10, kernel-image-2.2.10-powerpc-apus
Vulnerability : failing function and TLB flush
Problem-Type : local
Debian-specific: no
CVE ID : CAN-2004-0077
CERT advisory : VU#981222

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 version 2.2.10-13woody1 of 2.2 kernel images for the powerpc/apus architecture and in version 2.2.10-2 of Linux 2.2.10 source.

For the unstable distribution (sid) this problem will be fixed soon with the 2.4.20 kernel-image package for powerpc/apus. The old 2.2.10 kernel image will be removed from Debian unstable.

You are strongly advised to switch to the fixed 2.4.17 kernel-image package for powerpc/apus from woody until the 2.4.20 kernel-image package is fixed in the unstable distribution.

We recommend that you upgrade your Linux kernel package.

Upgrade Instructions
---------------------

wget url
will fetch the file for you
dpkg -i file.deb
will install the referenced file.

If you are using the apt-get package manager, use the line for sources.list as given below:

apt-get update
will update the internal database
apt-get upgrade
will install corrected packages

You may use an automated update by adding the resources from the footer to the proper configuration.


Debian GNU/Linux 3.0 alias woody
---------------------------------

Source archives:

http://security.debian.org/pool/updates/main/k/kernel-source-2.2.10/kernel-source-2.2.10_2.2.10-2.dsc
Size/MD5 checksum: 602 c30270ed0bb5a9b99775aefaff4b5037
http://security.debian.org/pool/updates/main/k/kernel-source-2.2.10/kernel-source-2.2.10_2.2.10-2.diff.gz
Size/MD5 checksum: 13862 b0dec7f7611601b2aab69d2117298641
http://security.debian.org/pool/updates/main/k/kernel-source-2.2.10/kernel-source-2.2.10_2.2.10.orig.tar.gz
Size/MD5 checksum: 13902979 e3e865f9103dfcea4a3715d66d89dad1

http://security.debian.org/pool/updates/main/k/kernel-image-2.2.10-powerpc-apus/kernel-image-2.2.10-powerpc-apus_2.2.10-13woody1.dsc
Size/MD5 checksum: 614 f6f2c6563e5eed7ff97d19551a1117fb
http://security.debian.org/pool/updates/main/k/kernel-image-2.2.10-powerpc-apus/kernel-image-2.2.10-powerpc-apus_2.2.10-13woody1.tar.gz
Size/MD5 checksum: 453378 865a8125d959621697b045edc210e200

Architecture independent components:

http://security.debian.org/pool/updates/main/k/kernel-source-2.2.10/kernel-doc-2.2.10_2.2.10-2_all.deb
Size/MD5 checksum: 866978 74d85ee7a1f5855710b3201b907967dd
http://security.debian.org/pool/updates/main/k/kernel-source-2.2.10/kernel-source-2.2.10_2.2.10-2_all.deb
Size/MD5 checksum: 11302672 7a66220ced59920d2cc50eff7003108f

PowerPC architecture:

http://security.debian.org/pool/updates/main/k/kernel-image-2.2.10-powerpc-apus/kernel-headers-2.2.10-apus_2.2.10-13woody1_powerpc.deb
Size/MD5 checksum: 1575772 03558d9d86b2c08194088cf5cece6811
http://security.debian.org/pool/updates/main/k/kernel-image-2.2.10-powerpc-apus/kernel-image-2.2.10-apus_2.2.10-13woody1_powerpc.deb
Size/MD5 checksum: 1303764 2a3c5a6a45c3978ae45c4572ddc0547b


These files will probably be moved into the stable distribution on its next revision.