USN-1448-1: Linux kernel vulnerabilities

21 May 2012

linux vulnerabilities

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

  • Ubuntu 12.04 LTS

Summary

Several security issues were fixed in the kernel.

Software Description

  • linux - Linux kernel

Details

A flaw was found in the Linux kernel’s KVM (Kernel Virtual Machine) virtual cpu setup. An unprivileged local user could exploit this flaw to crash the system leading to a denial of service. (CVE-2012-1601)

Steve Grubb reported a flaw with Linux fscaps (file system base capabilities) when used to increase the permissions of a process. For application on which fscaps are in use a local attacker can disable address space randomization to make attacking the process with raised privileges easier. (CVE-2012-2123)

A flaw was found in how the Linux kernel passed the replacement session keyring to a child process. An unprivileged local user could exploit this flaw to cause a denial of service (panic). (CVE-2012-2745)

Update instructions

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

Ubuntu 12.04 LTS
linux-image-3.2.0-24-generic - 3.2.0-24.38
linux-image-3.2.0-24-generic-pae - 3.2.0-24.38
linux-image-3.2.0-24-omap - 3.2.0-24.38
linux-image-3.2.0-24-powerpc-smp - 3.2.0-24.38
linux-image-3.2.0-24-powerpc64-smp - 3.2.0-24.38
linux-image-3.2.0-24-virtual - 3.2.0-24.38

To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.

After a standard system update you need to reboot your computer to make all the necessary changes.

ATTENTION: Due to an unavoidable ABI change the kernel updates have been given a new version number, which requires you to recompile and reinstall all third party kernel modules you might have installed. If you use linux-restricted-modules, you have to update that package as well to get modules which work with the new kernel version. Unless you manually uninstalled the standard kernel metapackages (e.g. linux-generic, linux-server, linux-powerpc), a standard system upgrade will automatically perform this as well.

References