USN-2589-1: Linux kernel (Utopic HWE) vulnerabilities

30 April 2015

linux-lts-utopic vulnerabilities

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

  • Ubuntu 14.04 LTS

Summary

Several security issues were fixed in the kernel.

Software Description

  • linux-lts-utopic - Linux hardware enablement kernel from Utopic

Details

Jan Beulich discovered the Xen virtual machine subsystem of the Linux kernel did not properly restrict access to PCI command registers. A local guest user could exploit this flaw to cause a denial of service (host crash). (CVE-2015-2150)

A stack overflow was discovered in the the microcode loader for the intel x86 platform. A local attacker could exploit this flaw to cause a denial of service (kernel crash) or to potentially execute code with kernel privileges. (CVE-2015-2666)

A privilege escalation was discovered in the fork syscall via the int80 entry on 64 bit kernels with 32 bit emulation support. An unprivileged local attacker could exploit this flaw to increase their privileges on the system. (CVE-2015-2830)

It was discovered that the Linux kernel’s IPv6 networking stack has a flaw that allows using route advertisement (RA) messages to set the ‘hop_limit’ to values that are too low. An unprivileged attacker on a local network could exploit this flaw to cause a denial of service (IPv6 messages dropped). (CVE-2015-2922)

Update instructions

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

Ubuntu 14.04 LTS
linux-image-3.16.0-36-generic - 3.16.0-36.48~14.04.1
linux-image-3.16.0-36-generic-lpae - 3.16.0-36.48~14.04.1
linux-image-3.16.0-36-lowlatency - 3.16.0-36.48~14.04.1
linux-image-3.16.0-36-powerpc-e500mc - 3.16.0-36.48~14.04.1
linux-image-3.16.0-36-powerpc-smp - 3.16.0-36.48~14.04.1
linux-image-3.16.0-36-powerpc64-emb - 3.16.0-36.48~14.04.1
linux-image-3.16.0-36-powerpc64-smp - 3.16.0-36.48~14.04.1

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