==========================================================================
Ubuntu Security Notice USN-3632-1
April 24, 2018

linux-azure vulnerabilities
==========================================================================

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

- Ubuntu 16.04 LTS

Summary:

Several security issues were fixed in the Linux kernel.

Software Description:
- linux-azure: Linux kernel for Microsoft Azure Cloud systems

Details:

It was discovered that a race condition leading to a use-after-free
vulnerability existed in the ALSA PCM subsystem of the Linux kernel. A
local attacker could use this to cause a denial of service (system crash)
or possibly execute arbitrary code. (CVE-2017-0861)

It was discovered that the KVM implementation in the Linux kernel allowed
passthrough of the diagnostic I/O port 0x80. An attacker in a guest VM
could use this to cause a denial of service (system crash) in the host OS.
(CVE-2017-1000407)

It was discovered that a use-after-free vulnerability existed in the
network namespaces implementation in the Linux kernel. A local attacker
could use this to cause a denial of service (system crash) or possibly
execute arbitrary code. (CVE-2017-15129)

It was discovered that the HugeTLB component of the Linux kernel did not
properly handle holes in hugetlb ranges. A local attacker could use this to
expose sensitive information (kernel memory). (CVE-2017-16994)

It was discovered that the netfilter component of the Linux did not
properly restrict access to the connection tracking helpers list. A local
attacker could use this to bypass intended access restrictions.
(CVE-2017-17448)

It was discovered that the netfilter passive OS fingerprinting (xt_osf)
module did not properly perform access control checks. A local attacker
could improperly modify the system-wide OS fingerprint list.
(CVE-2017-17450)

Dmitry Vyukov discovered that the KVM implementation in the Linux kernel
contained an out-of-bounds read when handling memory-mapped I/O. A local
attacker could use this to expose sensitive information. (CVE-2017-17741)

It was discovered that the Salsa20 encryption algorithm implementations in
the Linux kernel did not properly handle zero-length inputs. A local
attacker could use this to cause a denial of service (system crash).
(CVE-2017-17805)

It was discovered that the HMAC implementation did not validate the state
of the underlying cryptographic hash algorithm. A local attacker could use
this to cause a denial of service (system crash) or possibly execute
arbitrary code. (CVE-2017-17806)

It was discovered that the keyring implementation in the Linux kernel did
not properly check permissions when a key request was performed on a task's
default keyring. A local attacker could use this to add keys to
unauthorized keyrings. (CVE-2017-17807)

It was discovered that the Broadcom NetXtremeII ethernet driver in the
Linux kernel did not properly validate Generic Segment Offload (GSO) packet
sizes. An attacker could use this to cause a denial of service (interface
unavailability). (CVE-2018-1000026)

It was discovered that the Reliable Datagram Socket (RDS) implementation in
the Linux kernel contained an out-of-bounds write during RDMA page
allocation. An attacker could use this to cause a denial of service (system
crash) or possibly execute arbitrary code. (CVE-2018-5332)

Mohamed Ghannam discovered a null pointer dereference in the RDS (Reliable
Datagram Sockets) protocol implementation of the Linux kernel. A local
attacker could use this to cause a denial of service (system crash).
(CVE-2018-5333)

ee3/4ePS discovered that a race condition existed in loop block device
implementation in the Linux kernel. A local attacker could use this to
cause a denial of service (system crash) or possibly execute arbitrary
code. (CVE-2018-5344)

It was discovered that the Broadcom UniMAC MDIO bus controller driver in
the Linux kernel did not properly validate device resources. A local
attacker could use this to cause a denial of service (system crash).
(CVE-2018-8043)

Update instructions:

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

Ubuntu 16.04 LTS:
  linux-image-4.13.0-1014-azure   4.13.0-1014.17
  linux-image-azure               4.13.0.1014.16

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://usn.ubuntu.com/usn/usn-3632-1
  CVE-2017-0861, CVE-2017-1000407, CVE-2017-15129, CVE-2017-16994,
  CVE-2017-17448, CVE-2017-17450, CVE-2017-17741, CVE-2017-17805,
  CVE-2017-17806, CVE-2017-17807, CVE-2018-1000026, CVE-2018-5332,
  CVE-2018-5333, CVE-2018-5344, CVE-2018-8043

Package Information:
  https://launchpad.net/ubuntu/+source/linux-azure/4.13.0-1014.17