USN-3641-2: Linux kernel vulnerabilities

8 May 2018

linux, linux-lts-trusty vulnerabilities

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

  • Ubuntu 12.04 ESM

Summary

Several security issues were fixed in the Linux kernel.

Software Description

  • linux - Linux kernel
  • linux-lts-trusty - Linux hardware enablement kernel from Trusty for Precise ESM

Details

USN-3641-1 fixed vulnerabilities in the Linux kernel for Ubuntu 14.04 LTS, Ubuntu 16.04 LTS, and Ubuntu 17.10. This update provides the corresponding updates for Ubuntu 12.04 ESM.

Nick Peterson discovered that the Linux kernel did not properly handle debug exceptions following a MOV/POP to SS instruction. A local attacker could use this to cause a denial of service (system crash). This issue only affected the amd64 architecture. (CVE-2018-8897)

Andy Lutomirski discovered that the KVM subsystem of the Linux kernel did not properly emulate the ICEBP instruction following a MOV/POP to SS instruction. A local attacker in a KVM virtual machine could use this to cause a denial of service (guest VM crash) or possibly escalate privileges inside of the virtual machine. This issue only affected the i386 and amd64 architectures. (CVE-2018-1087)

Andy Lutomirski discovered that the Linux kernel did not properly perform error handling on virtualized debug registers. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-1000199)

Update instructions

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

Ubuntu 12.04 ESM
linux-image-3.13.0-147-generic - 3.13.0-147.196~precise1
linux-image-3.13.0-147-generic-lpae - 3.13.0-147.196~precise1
linux-image-3.2.0-134-generic - 3.2.0-134.180
linux-image-3.2.0-134-generic-pae - 3.2.0-134.180
linux-image-3.2.0-134-highbank - 3.2.0-134.180
linux-image-3.2.0-134-omap - 3.2.0-134.180
linux-image-3.2.0-134-powerpc-smp - 3.2.0-134.180
linux-image-3.2.0-134-powerpc64-smp - 3.2.0-134.180
linux-image-3.2.0-134-virtual - 3.2.0-134.180
linux-image-generic - 3.2.0.134.149
linux-image-generic-lpae-lts-trusty - 3.13.0.147.138
linux-image-generic-lts-trusty - 3.13.0.147.138
linux-image-generic-pae - 3.2.0.134.149
linux-image-highbank - 3.2.0.134.149
linux-image-omap - 3.2.0.134.149
linux-image-powerpc - 3.2.0.134.149
linux-image-powerpc-smp - 3.2.0.134.149
linux-image-powerpc64-smp - 3.2.0.134.149

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