USN-3469-1: Linux kernel vulnerabilities

31 October 2017

Several security issues were fixed in the Linux kernel.

Releases

Packages

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

Details

Anthony Perard discovered that the Xen virtual block driver did not
properly initialize some data structures before passing them to user space.
A local attacker in a guest VM could use this to expose sensitive
information from the host OS or other guest VMs. (CVE-2017-10911)

Bo Zhang discovered that the netlink wireless configuration interface in
the Linux kernel did not properly validate attributes when handling certain
requests. A local attacker with the CAP_NET_ADMIN could use this to cause a
denial of service (system crash). (CVE-2017-12153)

It was discovered that the nested KVM implementation in the Linux
kernel in some situations did not properly prevent second level guests
from reading and writing the hardware CR8 register. A local attacker
in a guest could use this to cause a denial of service (system crash).

It was discovered that the key management subsystem in the Linux kernel
did not properly restrict key reads on negatively instantiated keys. A
local attacker could use this to cause a denial of service (system crash).
(CVE-2017-12192)

It was discovered that an integer overflow existed in the sysfs interface
for the QLogic 24xx+ series SCSI driver in the Linux kernel. A local
privileged attacker could use this to cause a denial of service (system
crash). (CVE-2017-14051)

It was discovered that the ATI Radeon framebuffer driver in the Linux
kernel did not properly initialize a data structure returned to user space.
A local attacker could use this to expose sensitive information (kernel
memory). (CVE-2017-14156)

Dave Chinner discovered that the XFS filesystem did not enforce that the
realtime inode flag was settable only on filesystems on a realtime device.
A local attacker could use this to cause a denial of service (system
crash). (CVE-2017-14340)

ChunYu Wang discovered that the iSCSI transport implementation in the Linux
kernel did not properly validate data structures. A local attacker could
use this to cause a denial of service (system crash). (CVE-2017-14489)

It was discovered that the generic SCSI driver in the Linux kernel did not
properly initialize data returned to user space in some situations. A local
attacker could use this to expose sensitive information (kernel memory).
(CVE-2017-14991)

Dmitry Vyukov discovered that the Floating Point Unit (fpu) subsystem in
the Linux kernel did not properly handle attempts to set reserved bits in a
task's extended state (xstate) area. A local attacker could use this to
cause a denial of service (system crash). (CVE-2017-15537)

Pengfei Wang discovered that the Turtle Beach MultiSound audio device
driver in the Linux kernel contained race conditions when fetching
from the ring-buffer. A local attacker could use this to cause a
denial of service (infinite loop). (CVE-2017-9984, CVE-2017-9985)

Update instructions

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

Ubuntu 16.04

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.