USN-2317-1: Linux kernel (Trusty HWE) vulnerabilities

Ubuntu Security Notice USN-2317-1

18th August, 2014

linux-lts-trusty 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-lts-trusty - Linux hardware enablement kernel from Trusty

Details

Eric W. Biederman discovered a flaw with the mediation of mount flags in
the Linux kernel's user namespace subsystem. An unprivileged user could
exploit this flaw to by-pass mount restrictions, and potentially gain
administrative privileges. (CVE-2014-5207)

Kenton Varda discovered a flaw with read-only bind mounds when used with
user namespaces. An unprivileged local user could exploit this flaw to gain
full write privileges to a mount that should be read only. (CVE-2014-5206)

Update instructions

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

Ubuntu 12.04 LTS:
linux-image-3.13.0-34-generic-lpae 3.13.0-34.60~precise1
linux-image-3.13.0-34-generic 3.13.0-34.60~precise1

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-2014-5206, CVE-2014-5207