USN-3548-2: Linux kernel (HWE) vulnerability

Releases

• Ubuntu 16.04 ESM

Packages

• linux-azure - Linux kernel for Microsoft Azure Cloud systems
• linux-gcp - Linux kernel for Google Cloud Platform (GCP) systems
• linux-hwe - Linux hardware enablement (HWE) kernel
• linux-oem - Linux kernel for OEM processors

Details

USN-3548-1 fixed vulnerabilities in the Linux kernel for Ubuntu 17.10.
This update provides the corresponding updates for the Linux
Hardware Enablement (HWE) kernel from Ubuntu 17.10 for Ubuntu
16.04 LTS.

Jay Vosburgh discovered a logic error in the x86-64 syscall entry
implementation in the Linux kernel, introduced as part of the
mitigations for the Spectre vulnerability. A local attacker could use
this to cause a denial of service or possibly execute arbitrary code.

Update instructions

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

Ubuntu 16.04

• linux-image-4.13.0-1007-azure - 4.13.0-1007.9
• linux-image-4.13.0-1008-gcp - 4.13.0-1008.11
• linux-image-4.13.0-1019-oem - 4.13.0-1019.20
• linux-image-4.13.0-32-generic - 4.13.0-32.35~16.04.1
• linux-image-4.13.0-32-lowlatency - 4.13.0-32.35~16.04.1

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

• https://launchpad.net/bugs/1745564