USN-3392-1: Linux kernel regression

Ubuntu Security Notice USN-3392-1

16th 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


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


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.

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 version:

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

To update your system, please follow these instructions:

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.