--- title: 'USN-2420-1: Linux kernel vulnerabilities | Ubuntu security notices' description: Ubuntu is an open source software operating system that runs from the desktop, to the cloud, to all your internet connected things. url: https://ubuntu.com/security/notices/USN-2420-1 --- 1. [Ubuntu Security Notices](https://ubuntu.com/security/notices) 2. USN-2420-1 --- # USN-2420-1: Linux kernel vulnerabilities Publication date 25 November 2014 Overview Several security issues were fixed in the kernel. Releases [14.04 LTS](https://ubuntu.com/security/notices?release=trusty) --- Open side navigation ## Packages * [linux](https://ubuntu.com/security/cves?package=linux) - Linux kernel ## Details A flaw was discovered in how the Linux kernel's KVM (Kernel Virtual Machine) subsystem handles the CR4 control register at VM entry on Intel processors. A local host OS user can exploit this to cause a denial of service (kill arbitrary processes, or system disruption) by leveraging /dev/kvm access. ([CVE-2014-3690](https://ubuntu.com/security/CVE-2014-3690)) Don Bailey discovered a flaw in the LZO decompress algorithm used by the Linux kernel. An attacker could exploit this flaw to cause a denial of service (memory corruption or OOPS). ([CVE-2014-4608](https://ubuntu.com/security/CVE-2014-4608)) Andy Lutomirski discovered a flaw in how the Linux kernel handles pivot\_root when used with a chroot directory. A local user could exploit this flaw to cause a denial of service (mount-tree loop). ([CVE-2014-7970](https://ubuntu.com/security/CVE-2014-7970)) Andy Lutomirski discovered that the Linux kernel was not checking the CAP\_SYS\_ADMIN when... --- Show more ## Update instructions After a standard system update you need to reboot your computer to make all the necessary changes. [Learn more about how to get the fixes.](https://ubuntu.com/security/cves/about#security) 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. The problem can be corrected by updating your system to the following package versions: | Ubuntu Release | Package Version | | --- | --- | | 14.04 LTS trusty | [linux-image-3.13.0-40-generic](https://launchpad.net/ubuntu/+source/linux) –  [3.13.0-40.69](https://launchpad.net/ubuntu/+source/linux/3.13.0-40.69) | | | | [linux-image-3.13.0-40-generic-lpae](https://launchpad.net/ubuntu/+source/linux) –  [3.13.0-40.69](https://launchpad.net/ubuntu/+source/linux/3.13.0-40.69) | | | | [linux-image-3.13.0-40-lowlatency](https://launchpad.net/ubuntu/+source/linux) –  [3.13.0-40.69](https://launchpad.net/ubuntu/+source/linux/3.13.0-40.69) | | | | [linux-image-3.13.0-40-powerpc-e500](https://launchpad.net/ubuntu/+source/linux) –  [3.13.0-40.69](https://launchpad.net/ubuntu/+source/linux/3.13.0-40.69) | | | | [linux-image-3.13.0-40-powerpc-e500mc](https://launchpad.net/ubuntu/+source/linux) –  [3.13.0-40.69](https://launchpad.net/ubuntu/+source/linux/3.13.0-40.69) | | | | [linux-image-3.13.0-40-powerpc-smp](https://launchpad.net/ubuntu/+source/linux) –  [3.13.0-40.69](https://launchpad.net/ubuntu/+source/linux/3.13.0-40.69) | | | | [linux-image-3.13.0-40-powerpc64-emb](https://launchpad.net/ubuntu/+source/linux) –  [3.13.0-40.69](https://launchpad.net/ubuntu/+source/linux/3.13.0-40.69) | | | | [linux-image-3.13.0-40-powerpc64-smp](https://launchpad.net/ubuntu/+source/linux) –  [3.13.0-40.69](https://launchpad.net/ubuntu/+source/linux/3.13.0-40.69) | | | --- ### Reduce your security exposure Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines. [Get Ubuntu Pro](https://ubuntu.com/pro) ## References * [CVE-2014-7975](https://ubuntu.com/security/CVE-2014-7975) * [CVE-2014-7970](https://ubuntu.com/security/CVE-2014-7970) * [CVE-2014-4608](https://ubuntu.com/security/CVE-2014-4608) * [CVE-2014-3690](https://ubuntu.com/security/CVE-2014-3690) ## Related notices * [USN-2514-1](https://ubuntu.com/security/notices/USN-2514-1) * [USN-2513-1](https://ubuntu.com/security/notices/USN-2513-1) * [USN-2448-1](https://ubuntu.com/security/notices/USN-2448-1) * [USN-2447-1](https://ubuntu.com/security/notices/USN-2447-1) * [USN-2421-1](https://ubuntu.com/security/notices/USN-2421-1) * [USN-2419-1](https://ubuntu.com/security/notices/USN-2419-1) * [USN-2418-1](https://ubuntu.com/security/notices/USN-2418-1) * [USN-2417-1](https://ubuntu.com/security/notices/USN-2417-1) * [USN-2416-1](https://ubuntu.com/security/notices/USN-2416-1) * [USN-2415-1](https://ubuntu.com/security/notices/USN-2415-1) --- Show 2 more references --- Have additional questions? 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