USN-3055-1: Linux kernel vulnerabilities
10 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. (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)
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
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.