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Ubuntu Security Notice USN-3070-2
August 30, 2016

linux-raspi2 vulnerabilities
==========================================================================

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

- Ubuntu 16.04 LTS

Summary:

Several security issues were fixed in the kernel.

Software Description:
- linux-raspi2: Linux kernel for Raspberry Pi 2

Details:

A missing permission check when settings ACLs was discovered in nfsd. A
local user could exploit this flaw to gain access to any file by setting an
ACL. (CVE-2016-1237)

Kangjie Lu discovered an information leak in the Reliable Datagram Sockets
(RDS) implementation in the Linux kernel. A local attacker could use this
to obtain potentially sensitive information from kernel memory.
(CVE-2016-5244)

James Patrick-Evans discovered that the airspy USB device driver in the
Linux kernel did not properly handle certain error conditions. An attacker
with physical access could use this to cause a denial of service (memory
consumption). (CVE-2016-5400)

Yue Cao et al discovered a flaw in the TCP implementation's handling of
challenge acks in the Linux kernel. A remote attacker could use this to
cause a denial of service (reset connection) or inject content into an TCP
stream. (CVE-2016-5696)

Pengfei Wang discovered a race condition in the MIC VOP driver in the Linux
kernel. A local attacker could use this to cause a denial of service
(system crash) or obtain potentially sensitive information from kernel
memory. (CVE-2016-5728)

Cyril Bur discovered that on PowerPC platforms, the Linux kernel mishandled
transactional memory state on exec(). A local attacker could use this to
cause a denial of service (system crash) or possibly execute arbitrary
code. (CVE-2016-5828)

It was discovered that a heap based buffer overflow existed in the USB HID
driver in the Linux kernel. A local attacker could use this cause a denial
of service (system crash) or possibly execute arbitrary code.
(CVE-2016-5829)

It was discovered that the OverlayFS implementation in the Linux kernel did
not properly verify dentry state before proceeding with unlink and rename
operations. A local attacker could use this to cause a denial of service
(system crash). (CVE-2016-6197)

Update instructions:

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

Ubuntu 16.04 LTS:
  linux-image-4.4.0-1021-raspi2   4.4.0-1021.27

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-3070-2
  https://www.ubuntu.com/usn/usn-3070-1
  CVE-2016-1237, CVE-2016-5244, CVE-2016-5400, CVE-2016-5696,
  CVE-2016-5728, CVE-2016-5828, CVE-2016-5829, CVE-2016-6197

Package Information:
  https://launchpad.net/ubuntu/+source/linux-raspi2/4.4.0-1021.27