USN-4008-3: Linux kernel (Xenial HWE) vulnerabilities

7 June 2019

linux-lts-xenial, linux-aws vulnerabilities

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

  • Ubuntu 14.04 ESM

Summary

Several security issues were fixed in the Linux kernel.

Software Description

  • linux-aws - Linux kernel for Amazon Web Services (AWS) systems
  • linux-lts-xenial - Linux hardware enablement kernel from Xenial for Trusty

Details

USN-4008-1 fixed vulnerabilities in the Linux kernel for Ubuntu 16.04 LTS. This update provides the corresponding updates for the Linux Hardware Enablement (HWE) kernel from Ubuntu 16.04 LTS for Ubuntu 14.04 ESM.

Robert Święcki discovered that the Linux kernel did not properly apply Address Space Layout Randomization (ASLR) in some situations for setuid elf binaries. A local attacker could use this to improve the chances of exploiting an existing vulnerability in a setuid elf binary. (CVE-2019-11190)

It was discovered that a null pointer dereference vulnerability existed in the LSI Logic MegaRAID driver in the Linux kernel. A local attacker could use this to cause a denial of service (system crash). (CVE-2019-11810)

It was discovered that a race condition leading to a use-after-free existed in the Reliable Datagram Sockets (RDS) protocol implementation in the Linux kernel. The RDS protocol is blacklisted by default in Ubuntu. If enabled, a local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2019-11815)

Federico Manuel Bento discovered that the Linux kernel did not properly apply Address Space Layout Randomization (ASLR) in some situations for setuid a.out binaries. A local attacker could use this to improve the chances of exploiting an existing vulnerability in a setuid a.out binary. (CVE-2019-11191)

As a hardening measure, this update disables a.out support.

Update instructions

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

Ubuntu 14.04 ESM
linux-image-4.4.0-1045-aws - 4.4.0-1045.48
linux-image-4.4.0-150-generic - 4.4.0-150.176~14.04.1
linux-image-4.4.0-150-generic-lpae - 4.4.0-150.176~14.04.1
linux-image-4.4.0-150-lowlatency - 4.4.0-150.176~14.04.1
linux-image-aws - 4.4.0.1045.46
linux-image-generic-lpae-lts-xenial - 4.4.0.150.132
linux-image-generic-lts-xenial - 4.4.0.150.132
linux-image-lowlatency-lts-xenial - 4.4.0.150.132

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