USN-1452-1: Linux kernel vulnerabilities

Ubuntu Security Notice USN-1452-1

25th May, 2012

linux vulnerabilities

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

  • Ubuntu 11.10

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 version:

Ubuntu 11.10:
linux-image-3.0.0-20-generic-pae 3.0.0-20.34
linux-image-3.0.0-20-powerpc 3.0.0-20.34
linux-image-3.0.0-20-server 3.0.0-20.34
linux-image-3.0.0-20-omap 3.0.0-20.34
linux-image-3.0.0-20-generic 3.0.0-20.34
linux-image-3.0.0-20-powerpc-smp 3.0.0-20.34
linux-image-3.0.0-20-powerpc64-smp 3.0.0-20.34
linux-image-3.0.0-20-virtual 3.0.0-20.34

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

CVE-2012-1601, CVE-2012-2123, CVE-2012-2745