[USN-3055-1] Linux kernel vulnerabilities

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2
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=jkF+
-----END PGP SIGNATURE-----
==========================================================================
Ubuntu Security Notice USN-3055-1
August 10, 2016

linux 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: Linux kernel

Details:

Ben Hawkes discovered an integer overflow in the Linux netfilter
implementation. On systems running 32 bit kernels, a local unprivileged
attacker could use this to cause a denial of service (system crash) or
possibly execute arbitrary code with administrative privileges.
(CVE-2016-3135)

It was discovered that the keyring implementation in the Linux kernel did
not ensure a data structure was initialized before referencing it after an
error condition occurred. A local attacker could use this to cause a denial
of service (system crash). (CVE-2016-4470)

Sasha Levin discovered that a use-after-free existed in the percpu
allocator in the Linux kernel. A local attacker could use this to cause a
denial of service (system crash) or possibly execute arbitrary code with
administrative privileges. (CVE-2016-4794)

Kangjie Lu discovered an information leak in the netlink implementation of
the Linux kernel. A local attacker could use this to obtain sensitive
information from kernel memory. (CVE-2016-5243)

Update instructions:

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

Ubuntu 16.04 LTS:
linux-image-4.4.0-34-generic 4.4.0-34.53
linux-image-4.4.0-34-generic-lpae 4.4.0-34.53
linux-image-4.4.0-34-lowlatency 4.4.0-34.53
linux-image-4.4.0-34-powerpc-e500mc 4.4.0-34.53
linux-image-4.4.0-34-powerpc-smp 4.4.0-34.53
linux-image-4.4.0-34-powerpc64-emb 4.4.0-34.53
linux-image-4.4.0-34-powerpc64-smp 4.4.0-34.53

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:
http://www.ubuntu.com/usn/usn-3055-1
CVE-2016-3135, CVE-2016-4470, CVE-2016-4794, CVE-2016-5243

Package Information:
https://launchpad.net/ubuntu/+source/linux/4.4.0-34.53