USN-3055-1: Linux kernel vulnerabilities
Ubuntu Security Notice USN-3055-1
10th August, 2016
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 16.04 LTS
Several security issues were fixed in the kernel.
- linux - Linux kernel
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.
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)
The problem can be corrected by updating your system to the following package version:
- Ubuntu 16.04 LTS:
- linux-image-4.4.0-34-generic 4.4.0-34.53
- linux-image-4.4.0-34-powerpc-e500mc 4.4.0-34.53
- linux-image-4.4.0-34-powerpc64-smp 4.4.0-34.53
- linux-image-4.4.0-34-generic-lpae 4.4.0-34.53
- linux-image-4.4.0-34-powerpc64-emb 4.4.0-34.53
- linux-image-4.4.0-34-powerpc-smp 4.4.0-34.53
- linux-image-4.4.0-34-lowlatency 4.4.0-34.53
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
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.