USN-3981-2: Linux kernel (HWE) vulnerabilities

15 May 2019

linux-hwe, linux-azure, linux-gcp, linux-oracle vulnerabilities

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

  • Ubuntu 16.04 LTS
  • Ubuntu 14.04 ESM

Summary

Several security issues were fixed in the Linux kernel.

Software Description

  • 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-oracle - Linux kernel for Oracle Cloud systems

Details

USN-3981-1 fixed vulnerabilities in the Linux kernel for Ubuntu 18.04 LTS. This update provides the corresponding updates for the Linux Hardware Enablement (HWE) kernel from Ubuntu 18.04 LTS for Ubuntu 16.04 LTS and for the Linux Azure kernel for Ubuntu 14.04 LTS.

Ke Sun, Henrique Kawakami, Kekai Hu, Rodrigo Branco, Giorgi Maisuradze, Dan Horea Lutas, Andrei Lutas, Volodymyr Pikhur, Stephan van Schaik, Alyssa Milburn, Sebastian Österlund, Pietro Frigo, Kaveh Razavi, Herbert Bos, Cristiano Giuffrida, Moritz Lipp, Michael Schwarz, and Daniel Gruss discovered that memory previously stored in microarchitectural fill buffers of an Intel CPU core may be exposed to a malicious process that is executing on the same CPU core. A local attacker could use this to expose sensitive information. (CVE-2018-12130)

Brandon Falk, Ke Sun, Henrique Kawakami, Kekai Hu, Rodrigo Branco, Stephan van Schaik, Alyssa Milburn, Sebastian Österlund, Pietro Frigo, Kaveh Razavi, Herbert Bos, and Cristiano Giuffrida discovered that memory previously stored in microarchitectural load ports of an Intel CPU core may be exposed to a malicious process that is executing on the same CPU core. A local attacker could use this to expose sensitive information. (CVE-2018-12127)

Ke Sun, Henrique Kawakami, Kekai Hu, Rodrigo Branco, Marina Minkin, Daniel Moghimi, Moritz Lipp, Michael Schwarz, Jo Van Bulck, Daniel Genkin, Daniel Gruss, Berk Sunar, Frank Piessens, and Yuval Yarom discovered that memory previously stored in microarchitectural store buffers of an Intel CPU core may be exposed to a malicious process that is executing on the same CPU core. A local attacker could use this to expose sensitive information. (CVE-2018-12126)

Vasily Averin and Evgenii Shatokhin discovered that a use-after-free vulnerability existed in the NFS41+ subsystem when multiple network namespaces are in use. A local attacker in a container could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-16884)

Ke Sun, Henrique Kawakami, Kekai Hu, Rodrigo Branco, Volodrmyr Pikhur, Moritz Lipp, Michael Schwarz, Daniel Gruss, Stephan van Schaik, Alyssa Milburn, Sebastian Österlund, Pietro Frigo, Kaveh Razavi, Herbert Bos, and Cristiano Giuffrida discovered that uncacheable memory previously stored in microarchitectural buffers of an Intel CPU core may be exposed to a malicious process that is executing on the same CPU core. A local attacker could use this to expose sensitive information. (CVE-2019-11091)

Matteo Croce, Natale Vinto, and Andrea Spagnolo discovered that the cgroups subsystem of the Linux kernel did not properly account for SCTP socket buffers. A local attacker could use this to cause a denial of service (system crash). (CVE-2019-3874)

Alex Williamson discovered that the vfio subsystem of the Linux kernel did not properly limit DMA mappings. A local attacker could use this to cause a denial of service (memory exhaustion). (CVE-2019-3882)

Hugues Anguelkov discovered that the Broadcom Wifi driver in the Linux kernel contained a heap buffer overflow. A physically proximate attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2019-9500)

Hugues Anguelkov discovered that the Broadcom Wifi driver in the Linux kernel did not properly prevent remote firmware events from being processed for USB Wifi devices. A physically proximate attacker could use this to send firmware events to the device. (CVE-2019-9503)

Update instructions

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

Ubuntu 16.04 LTS
linux-image-4.15.0-1013-oracle - 4.15.0-1013.15~16.04.1
linux-image-4.15.0-1032-gcp - 4.15.0-1032.34~16.04.1
linux-image-4.15.0-1045-azure - 4.15.0-1045.49
linux-image-4.15.0-50-generic - 4.15.0-50.54~16.04.1
linux-image-4.15.0-50-generic-lpae - 4.15.0-50.54~16.04.1
linux-image-4.15.0-50-lowlatency - 4.15.0-50.54~16.04.1
linux-image-azure - 4.15.0.1045.49
linux-image-gcp - 4.15.0.1032.46
linux-image-generic-hwe-16.04 - 4.15.0.50.71
linux-image-generic-lpae-hwe-16.04 - 4.15.0.50.71
linux-image-gke - 4.15.0.1032.46
linux-image-lowlatency-hwe-16.04 - 4.15.0.50.71
linux-image-oem - 4.15.0.50.71
linux-image-oracle - 4.15.0.1013.7
linux-image-virtual-hwe-16.04 - 4.15.0.50.71
Ubuntu 14.04 ESM
linux-image-4.15.0-1045-azure - 4.15.0-1045.49~14.04.1
linux-image-azure - 4.15.0.1045.32

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.

Please note that fully mitigating the Microarchitectural Data Sampling (MDS) issues (CVE-2018-12126, CVE-2018-12127, CVE-2018-12130, and CVE-2019-11091) requires corresponding processor microcode/firmware updates or, in virtual environments, hypervisor updates.

References