USN-3443-2: Linux kernel (HWE) vulnerabilities
10 October 2017
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 16.04 LTS
Several security issues were fixed in the Linux kernel.
- linux-hwe - Linux hardware enablement (HWE) kernel
USN-3443-1 fixed vulnerabilities in the Linux kernel for Ubuntu 17.04. This update provides the corresponding updates for the Linux Hardware Enablement (HWE) kernel from Ubuntu 17.04 for Ubuntu 16.04 LTS.
It was discovered that on the PowerPC architecture, the kernel did not properly sanitize the signal stack when handling sigreturn(). A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2017-1000255)
Andrey Konovalov discovered that a divide-by-zero error existed in the TCP stack implementation in the Linux kernel. A local attacker could use this to cause a denial of service (system crash). (CVE-2017-14106)
The problem can be corrected by updating your system to the following package versions:
- Ubuntu 16.04 LTS
- linux-image-4.10.0-37-generic - 4.10.0-37.41~16.04.1
- linux-image-4.10.0-37-generic-lpae - 4.10.0-37.41~16.04.1
- linux-image-4.10.0-37-lowlatency - 4.10.0-37.41~16.04.1
- linux-image-generic-hwe-16.04 - 18.104.22.168.39
- linux-image-generic-lpae-hwe-16.04 - 22.214.171.124.39
- linux-image-lowlatency-hwe-16.04 - 126.96.36.199.39
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.