USN-3392-1: Linux kernel regression

16 August 2017

linux, linux-aws, linux-gke, linux-raspi2, linux-snapdragon regression

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

  • Ubuntu 16.04 LTS

Summary

USN-3378-1 introduced a regression in the Linux kernel.

Software Description

  • linux - Linux kernel
  • linux-aws - Linux kernel for Amazon Web Services (AWS) systems
  • linux-gke - Linux kernel for Google Container Engine (GKE) systems
  • linux-raspi2 - Linux kernel for Raspberry Pi 2
  • linux-snapdragon - Linux kernel for Snapdragon processors

Details

USN-3378-1 fixed vulnerabilities in the Linux kernel. Unfortunately, a regression was introduced that prevented conntrack from working correctly in some situations. This update fixes the problem.

We apologize for the inconvenience.

Original advisory details:

Fan Wu and Shixiong Zhao discovered a race condition between inotify events and vfs rename operations in the Linux kernel. An unprivileged local attacker could use this to cause a denial of service (system crash) or execute arbitrary code. (CVE-2017-7533)

It was discovered that the Linux kernel did not properly restrict RLIMIT_STACK size. A local attacker could use this in conjunction with another vulnerability to possibly execute arbitrary code. (CVE-2017-1000365)

李强 discovered that the Virtio GPU driver in the Linux kernel did not properly free memory in some situations. A local attacker could use this to cause a denial of service (memory consumption). (CVE-2017-10810)

石磊 discovered that the RxRPC Kerberos 5 ticket handling code in the Linux kernel did not properly verify metadata. A remote attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2017-7482)

Update instructions

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

Ubuntu 16.04 LTS
linux-image-4.4.0-1027-gke - 4.4.0-1027.27
linux-image-4.4.0-1031-aws - 4.4.0-1031.40
linux-image-4.4.0-1070-raspi2 - 4.4.0-1070.78
linux-image-4.4.0-1072-snapdragon - 4.4.0-1072.77
linux-image-4.4.0-92-generic - 4.4.0-92.115
linux-image-4.4.0-92-generic-lpae - 4.4.0-92.115
linux-image-4.4.0-92-lowlatency - 4.4.0-92.115
linux-image-4.4.0-92-powerpc-e500mc - 4.4.0-92.115
linux-image-4.4.0-92-powerpc-smp - 4.4.0-92.115
linux-image-4.4.0-92-powerpc64-emb - 4.4.0-92.115
linux-image-4.4.0-92-powerpc64-smp - 4.4.0-92.115
linux-image-aws - 4.4.0.1031.33
linux-image-generic - 4.4.0.92.97
linux-image-generic-lpae - 4.4.0.92.97
linux-image-gke - 4.4.0.1027.28
linux-image-lowlatency - 4.4.0.92.97
linux-image-powerpc-e500mc - 4.4.0.92.97
linux-image-powerpc-smp - 4.4.0.92.97
linux-image-powerpc64-emb - 4.4.0.92.97
linux-image-powerpc64-smp - 4.4.0.92.97
linux-image-raspi2 - 4.4.0.1070.70
linux-image-snapdragon - 4.4.0.1072.64

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