USN-2909-1: Linux kernel (Utopic HWE) vulnerabilities

22 February 2016

Several security issues were fixed in the kernel.

Releases

Packages

  • linux-lts-utopic - Linux hardware enablement kernel from Utopic

Details

halfdog discovered that OverlayFS, when mounting on top of a FUSE mount,
incorrectly propagated file attributes, including setuid. A local
unprivileged attacker could use this to gain privileges. (CVE-2016-1576)

halfdog discovered that OverlayFS in the Linux kernel incorrectly
propagated security sensitive extended attributes, such as POSIX ACLs. A
local unprivileged attacker could use this to gain privileges.
(CVE-2016-1575)

It was discovered that the Linux kernel's Filesystem in Userspace (FUSE)
implementation did not handle initial zero length segments properly. A
local attacker could use this to cause a denial of service (unkillable
task). (CVE-2015-8785)

Update instructions

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

Ubuntu 14.04

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.

Related notices

  • USN-2908-2: linux-image-4.2.0-30-generic-lpae, linux-image-4.2.0-30-generic, linux-image-4.2.0-30-powerpc-e500mc, linux-image-4.2.0-30-powerpc64-emb, linux-image-4.2.0-30-powerpc64-smp, linux-image-4.2.0-30-lowlatency, linux-lts-wily, linux-image-4.2.0-30-powerpc-smp
  • USN-2908-3: linux-image-4.2.0-1025-raspi2, linux-raspi2
  • USN-2908-1: linux-image-4.2.0-30-generic-lpae, linux-image-4.2.0-30-generic, linux-image-4.2.0-30-powerpc-e500mc, linux-image-4.2.0-30-powerpc64-emb, linux, linux-image-4.2.0-30-powerpc64-smp, linux-image-4.2.0-30-lowlatency, linux-image-4.2.0-30-powerpc-smp
  • USN-2907-1: linux-image-3.13.0-79-lowlatency, linux-image-3.13.0-79-generic, linux, linux-image-3.13.0-79-powerpc-e500mc, linux-image-3.13.0-79-powerpc-smp, linux-image-3.13.0-79-powerpc64-smp, linux-image-3.13.0-79-powerpc64-emb, linux-image-3.13.0-79-generic-lpae, linux-image-3.13.0-79-powerpc-e500
  • USN-2910-1: linux-image-3.19.0-51-powerpc64-smp, linux-image-3.19.0-51-powerpc-smp, linux-image-3.19.0-51-lowlatency, linux-image-3.19.0-51-generic-lpae, linux-image-3.19.0-51-generic, linux-lts-vivid, linux-image-3.19.0-51-powerpc-e500mc, linux-image-3.19.0-51-powerpc64-emb
  • USN-2886-1: linux-image-3.2.0-98-highbank, linux-image-3.2.0-98-virtual, linux-image-3.2.0-98-powerpc64-smp, linux-image-3.2.0-98-omap, linux-image-3.2.0-98-powerpc-smp, linux-image-3.2.0-98-generic-pae, linux-image-3.2.0-98-generic, linux
  • USN-2907-2: linux-image-3.13.0-79-generic, linux-image-3.13.0-79-generic-lpae, linux-lts-trusty
  • USN-2886-2: linux-ti-omap4, linux-image-3.2.0-1476-omap4