USN-2887-2: Linux kernel (Trusty HWE) vulnerabilities

2 February 2016

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

It was discovered that a use-after-free vulnerability existed in the AF_UNIX implementation in the Linux kernel. A local attacker could use crafted epoll_ctl calls to cause a denial of service (system crash) or expose sensitive information. (CVE-2013-7446)

It was discovered that the KVM implementation in the Linux kernel did not properly restore the values of the Programmable Interrupt Timer (PIT). A user-assisted attacker in a KVM guest could cause a denial of service in the host (system crash). (CVE-2015-7513)

Sasha Levin discovered that the Reliable Datagram Sockets (RDS) implementation in the Linux kernel had a race condition when checking whether a socket was bound or not. A local attacker could use this to cause a denial of service (system crash). (CVE-2015-7990)

It was discovered that the Btrfs implementation in the Linux kernel incorrectly handled compressed inline extants on truncation. A local attacker could use this to expose sensitive information. (CVE-2015-8374)

Update instructions

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

Ubuntu 12.04 LTS
linux-image-3.13.0-77-generic - 3.13.0-77.121~precise1
linux-image-3.13.0-77-generic-lpae - 3.13.0-77.121~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. Unless you manually uninstalled the standard kernel metapackages (e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual, linux-powerpc), a standard system upgrade will automatically perform this as well.

References