USN-3169-1: Linux kernel vulnerabilities
11 January 2017
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
Dmitry Vyukov discovered that the KVM implementation in the Linux kernel did not properly initialize the Code Segment (CS) in certain error cases. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2016-9756)
Andrey Konovalov discovered that signed integer overflows existed in the setsockopt() system call when handling the SO_SNDBUFFORCE and SO_RCVBUFFORCE options. A local attacker with the CAP_NET_ADMIN capability could use this to cause a denial of service (system crash or memory corruption). (CVE-2016-9793)
Baozeng Ding discovered a race condition that could lead to a use-after- free in the Advanced Linux Sound Architecture (ALSA) subsystem of the Linux kernel. A local attacker could use this to cause a denial of service (system crash). (CVE-2016-9794)
The problem can be corrected by updating your system to the following package versions:
- Ubuntu 16.04 LTS
- linux-image-4.4.0-59-generic - 4.4.0-59.80
- linux-image-4.4.0-59-generic-lpae - 4.4.0-59.80
- linux-image-4.4.0-59-lowlatency - 4.4.0-59.80
- linux-image-4.4.0-59-powerpc-e500mc - 4.4.0-59.80
- linux-image-4.4.0-59-powerpc-smp - 4.4.0-59.80
- linux-image-4.4.0-59-powerpc64-emb - 4.4.0-59.80
- linux-image-4.4.0-59-powerpc64-smp - 4.4.0-59.80
- linux-image-generic - 18.104.22.168.62
- linux-image-generic-lpae - 22.214.171.124.62
- linux-image-lowlatency - 126.96.36.199.62
- linux-image-powerpc-e500mc - 188.8.131.52.62
- linux-image-powerpc-smp - 184.108.40.206.62
- linux-image-powerpc64-emb - 220.127.116.11.62
- linux-image-powerpc64-smp - 18.104.22.168.62
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.