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

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 version:

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

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

https://bugs.launchpad.net/bugs/1709032, https://usn.ubuntu.com/usn/usn-3378-1