==========================================================================
Ubuntu Security Notice USN-3392-2
August 16, 2017

linux-lts-xenial regression
==========================================================================

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

- Ubuntu 14.04 LTS

Summary:

USN-3378-2 introduced a regression the Linux Hardware Enablement
kernel.

Software Description:
- linux-lts-xenial: Linux hardware enablement kernel from Xenial for Trusty

Details:

USN-3392-1 fixed a regression 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 LTS.

USN-3378-2 fixed vulnerabilities in the Linux Hardware Enablement
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)

 aea1/4o 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)

 c3cPS 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 14.04 LTS:
  linux-image-4.4.0-92-generic    4.4.0-92.115~14.04.1
  linux-image-4.4.0-92-generic-lpae  4.4.0-92.115~14.04.1
  linux-image-4.4.0-92-lowlatency  4.4.0-92.115~14.04.1
  linux-image-4.4.0-92-powerpc-e500mc  4.4.0-92.115~14.04.1
  linux-image-4.4.0-92-powerpc-smp  4.4.0-92.115~14.04.1
  linux-image-4.4.0-92-powerpc64-emb  4.4.0-92.115~14.04.1
  linux-image-4.4.0-92-powerpc64-smp  4.4.0-92.115~14.04.1
  linux-image-generic-lpae-lts-xenial  4.4.0.92.76
  linux-image-generic-lts-xenial  4.4.0.92.76
  linux-image-lowlatency-lts-xenial  4.4.0.92.76
  linux-image-powerpc-e500mc-lts-xenial  4.4.0.92.76
  linux-image-powerpc-smp-lts-xenial  4.4.0.92.76
  linux-image-powerpc64-emb-lts-xenial  4.4.0.92.76
  linux-image-powerpc64-smp-lts-xenial  4.4.0.92.76

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://www.ubuntu.com/usn/usn-3392-2
  https://www.ubuntu.com/usn/usn-3392-1
  https://bugs.launchpad.net/bugs/1709032, https://usn.ubuntu.com/usn/usn-3378-2

Package Information:
  https://launchpad.net/ubuntu/+source/linux-lts-xenial/4.4.0-92.115~14.04.1